Search

The direction and magnitude of association between maternal exposure to ambient air pollutants across gestational windows and offspring risk of autism spectrum disorders (ASD) remains unclear. We sought to evaluate the time-varying effects of prenatal air pollutant exposure on ASD. We conducted a matched case-control study of singleton term children born in Ontario, Canada from 1-Apr-2012 to 31-Dec-2016. Provincial birth registry data were linked with applied behavioural analysis services and ambient air pollutant datasets to ascertain prenatal exposure to nitrogen dioxide (NO 2 ), ground-level ozone (O 3 ), fine particulate matter (PM 2.5 ), and ASD diagnoses. Covariate balance between cases and controls was established using coarsened exact matching. Conditional logistic regression was used to assess the association between prenatal air pollutant exposure and ASD. Distributed lag non-linear models (DLNM) were used to examine the effects of single-pollutant exposure by prenatal week. Sensitivity analyses were conducted to assess the impact of exposure period on the observed findings. The final sample included 1589 ASD cases and 7563 controls. Compared to controls, cases were more likely to be born to mothers living in urban areas, delivered by Caesarean section, and assigned male sex at birth. NO 2 was a consistent and significant contributor to ASD risk after accounting for co-exposure to O 3 , PM 2.5 and covariates. The odds ratio per interquartile range increase was 2.1 (95%CI 1.8-2.3) pre-conception, 2.2 (2.0-2.5) for the 1st trimester, 2.2 (1.9-2.5) for the 2nd trimester, and 2.1 (1.9-2.4) for the 3rd trimester. In contrast, findings for O 3 and PM 2.5 with ASD were inconsistent. Findings from DLNM and sensitivity analyses were similar. Exposure to NO 2 before and during pregnancy was significantly associated with ASD in offspring. The relationship between prenatal O 3 and PM 2.5 exposure and ASD remains unclear. Further investigation into the combined effects of multi-pollutant exposure on child neurodevelopment is warranted., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Objectives: The prevalence of gestational diabetes mellitus (GDM) has been increasing globally over recent decades; however, underlying reasons for the increase remain unclear. We analyzed trends in GDM rates and evaluated risk factors associated with the observed trends in Ontario, Canada., Methods: We conducted a retrospective population-based cohort study using the Better Outcomes Registry and Network Ontario, linked with the Canadian Institute for Health Information Discharge Abstract Database. All pregnant individuals who had a singleton hospital delivery from 1 April 2012 to 31 March 2020 were included. We calculated rates and 95% CIs for GDM by year of delivery and contrasted fiscal year 2019/20 with 2012/13. Temporal trends in GDM were quantified using crude and adjusted risk ratios by modified Poisson regression. We further quantified the temporal increase attributable to changes in maternal characteristics by decomposition analysis., Results: Among 1 044 258 pregnant individuals, 82 896 (7.9%) were diagnosed with GDM over the 8 years. GDM rate rose from 6.1 to 10.4 per 100 deliveries between fiscal years 2012/13 and 2019/20. The risk of GDM in 2019/20 was 1.53 times (95% CI 1.50-1.56) higher compared with 2012/13. 27% of the increase in GDM was due to changes in maternal age, 8 BMI, and Asian ethnicity., Conclusions: The GDM rate has been consistently increasing in Ontario, Canada. The contribution of increasing maternal age, pre-pregnancy obesity, and Asian ethnicity to the recent increase in GDM is notable. Further investigation is required to better understand the contributors to increasing GDM., (Copyright © 2024 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.)

Background: Increasing evidence links early life residential exposure to natural urban environmental attributes and positive health outcomes in children. However, few studies have focused on their protective effects on the risk of autism spectrum disorder (ASD). The aim of this study was to investigate the associations of neighborhood greenspace, and active living environments during pregnancy with ASD in young children (≤6 years)., Methods: We conducted a population-based matched case-control study of singleton term births in Ontario, Canada for 2012-2016. The ASD and environmental data was generated using the Ontario Autism Spectrum Profile, the Better Outcomes Registry & Network Ontario, and Canadian Urban Environmental Health Research Consortium. We employed conditional logistic regressions to estimate the odds ratio (OR) between ASD and environmental factors characterizing selected greenspace metrics and neighborhoods conducive to active living (i.e., green view index (GVI), normalized difference vegetation index (NDVI), tree canopy, park proximity and active living environments index (ALE))., Results: We linked 8643 mother-child pairs, including 1554 cases (18%). NDVI (OR 1.034, 0.944-1.024, per Inter Quartile Range [IQR] = 0.08), GVI (OR 1.025, 95% CI 0.953-1.087, per IQR = 9.45%), tree canopy (OR 0.992, 95% CI 0.903-1.089, per IQR = 6.24%) and the different categories of ALE were not associated with ASD in adjusted models for air pollution. In contrast, living closer to a park was protective (OR 0.888, 0.833-0.948, per 0.06 increase in park proximity index), when adjusted for air pollution., Conclusions: This study reported mixed findings showing both null and beneficial effects of green spaces and active living environments on ASD. Further investigations are warranted to elucidate the role of exposure to greenspaces and active living environments on the development of ASD., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2024. Published by Elsevier Inc. All rights reserved.)

Objectives: Investigations about cesarean delivery (CD) on maternal request (CDMR) and infant infection risk frequently rely on administrative data with poorly defined indications for CD. We sought to determine the association between CDMR and infant infection using an intent-to-treat approach., Methods: This was a population-based cohort study of low-risk singleton pregnancies with a term live birth in Ontario, Canada between April 2012 and March 2018. Subjects with prior CD were excluded. Outcomes included upper and lower respiratory tract infections, gastrointestinal infections, otitis media, and a composite of these 4. Relative risk and 95% CI were calculated for component and composite outcomes up to 1 year following planned CDMR versus planned vaginal deliveries (VDs). Subgroup and sensitivity analyses included age at infection (≤28 vs. >28 days), type of care (ambulatory vs. hospitalisation), restricting the cohort to nulliparous pregnancies, and including individuals with previous CD. Last, we re-examined outcome risk on an as-treated basis (actual CD vs. actual VD)., Results: Of 422 134 pregnancies, 0.4% (1827) resulted in a planned CDMR. After adjusting for covariates, planned CDMR was not associated with a risk of composite infant infections (adjusted relative risk 1.02; 95% CI 0.92-1.11). Findings for component infection outcomes, subgroup, and sensitivity analyses were similar. However, the as-treated analysis of the role of delivery mode on infant risk for infection demonstrated that actual CD (planned and unplanned) was associated with an increased risk for infant infections compared to actual VD., Conclusions: Planned CDMR is not associated with increased risk for neonatal or infant infections compared with planned VD. Study design must be carefully considered when investigating the impact of CDMR on infant infection outcomes., (Copyright © 2024 The Author. Published by Elsevier Inc. All rights reserved.)

We used a prospective cohort of pregnant women at 12 to 20 weeks gestation between 2002 and 2008 in Ottawa and Kingston to evaluate the impact of early pregnancy folic acid supplementation on the risk of gestational diabetes mellitus. Among 7552 eligible women, 84 (1.11%) were diagnosed of gestational diabetes mellitus. Non-significant associations were observed between gestational diabetes mellitus and folate supplementation, homocysteine levels, and methylenetetrahydrofolate reductase 677 TT genotype. Although we found no significant associations between folic acid supplementation and the risk of gestational diabetes mellitus, genetic associations were not confounded by lifestyle or socioeconomic factors, which may have biased previous studies., (Copyright © 2021 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.)

Objective: Maternal weight during pregnancy impacts the health of both mother and baby. This project investigated associations between maternal pre-pregnancy body mass index (BMI) and the child's future health service utilization., Methods: The study population comprised all women who delivered a singleton, live infant in Ontario between 2012 and 2014, and was assembled from data contained in the provincial birth registry. Health service utilization in the 24 months following birth was examined by linking data from the registry with other provincial health administrative databases housed at ICES., Results: A total of 258 005 records were available for analysis. After adjusting for infant sex and maternal age, smoking status, income quintile, and pre-existing or gestational diabetes or hypertension, children born to mothers who were overweight or had obesity prior to pregnancy had increased rates of hospitalization (overweight adjusted incidence rate ratio [aIRR] 1.09, 95% confidence interval [CI] 1.06-1.12; obesity aIRR 1.20, 95% CI 1.17-1.24), physician visits (overweight aIRR 1.03, 95% CI 1.03-1.04; obesity aIRR 1.05, 95% CI 1.04-1.05) and emergency department visits (overweight aIRR 1.12, 95% CI 1.10-1.13; obesity aIRR 1.27, 95% CI 1.25-1.29) than infants born to mothers with normal pre-pregnancy BMI., Conclusion: Excess maternal weight was associated with greater pediatric health service utilization. Rates of health service utilization appeared to increase with maternal pre-pregnancy BMI. Future study of the reasons behind this increase may allow for early education, diagnosis, and intervention in this at-risk population., (Copyright © 2021 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.)

Objective: Comprehensive comparison of maternal and neonatal outcomes between placenta previa with and without a history of caesarean delivery is sparse in the literature. The objective of this study was to conduct such an analysis., Methods: We conducted a retrospective cohort study involving all cases of placenta previa among 56 070 singleton births at two tertiary care hospitals in Guangdong, China, between January 2014 and December 2018. Placenta previa cases were divided into two groups: those with a history of caesarean delivery and those without. We first compared baseline characteristics and then compared maternal and neonatal outcomes between the two groups. Multiple log binomial regression and multiple linear regression analyses were performed to estimate independent association between a history of caesarean delivery and adverse maternal and neonatal outcomes., Results: A total of 773 placenta previa cases were included in the final analysis. Of them, 546 had a history of cesarean delivery and 227 did not. Compared with placenta previa cases without a history of cesarean delivery, placenta previa cases with a history of caesarean delivery were at increased risks of placenta accrete and increta, uterine rapture, shock, severe anemia, hysterectomy, and increased bleeding and hospital costs. No differences in neonatal outcomes between the two groups were observed., Conclusions: History of caesarean delivery is associated with an increased risk of adverse maternal outcomes but not with neonatal outcomes with placenta previa., (Copyright © 2021 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.)

Background: Periconceptional folic acid (FA) supplementation is recommended to prevent neural tube defects; however, the extent to which recommendations are met through dietary sources and supplements is not clear., Objectives: Our objective was to evaluate the dietary and supplemental intakes of FA in a Canadian pregnancy cohort and to determine the proportions of pregnant women exceeding the Estimated Average Requirement (EAR) and Tolerable Upper Intake Level (UL)., Methods: FACT (the Folic Acid Clinical Trial) was an international multicenter, randomized, double-blinded, placebo-controlled, phase III trial investigating FA for the prevention of pre-eclampsia in high-risk pregnancies. Participants were enrolled from Canadian sites at 8-16 weeks of gestation. Dietary and supplemental FA intake data were collected through participant interviews and FFQs at the time of FACT enrollment. Categorical data were summarized as n (%) and continuous data as median (IQR)., Results: This study included 1198 participants. Participants consumed 485 μg dietary folate equivalents (DFE)/d (IQR: 370-630 μg DFE/d) from dietary sources of folate and FA. Through diet alone, 43.4% of participants consumed ≥520 μg DFE/d, the EAR for pregnant individuals. Of the 91.9% of participants who consumed daily FA supplements, 0.4% consumed <400 μg FA/d and 96.0% consumed ≥1000 μg/d, the UL for FA. Median (IQR) total folate intake was 2167 μg DFE/d (2032-2325 μg DFE/d); 95.3% of participants met or exceeded the EAR from all sources, but 1069 (89.2%) participants exceeded the UL., Conclusions: The majority of participants in this Canadian pregnancy cohort did not consume the recommended amount of folate from dietary sources. However, most prenatal supplements contained 1000 μg FA, resulting in the majority of women exceeding the UL. With no additional benefit associated with FA intakes beyond the UL for most women, modification of prenatal supplement formulations may be warranted to ensure women meet but do not exceed recommended FA intakes.FACT was registered at clinicaltrials.gov as NCT01355159 and at isrctn.com as ISRCTN23781770., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society for Nutrition.)

Background: Periconceptional folic acid (FA) supplementation is recommended to prevent the occurrence of neural tube defects. Currently, most over-the-counter FA supplements in Canada and the United States contain 1 mg FA and some women are prescribed 5 mg FA/d. High-dose FA is hypothesized to impair 1-carbon metabolism. We aimed to determine folate and 1-carbon metabolism biomarkers in pregnant women exposed to 1 mg or 5 mg FA., Objectives: This was an ancillary study within the Folic Acid Clinical Trial (FACT), a randomized, double-blinded, placebo-controlled, phase III trial designed to assess the efficacy of high-dose FA to prevent preeclampsia., Methods: For FACT, women were randomized at 8-16 gestational weeks to receive daily 4.0 mg FA (high dose) or placebo (low dose) plus their usual supplementation (≤1.1 mg). Women were recruited from 3 Canadian FACT centers and provided nonfasting blood samples at 24-26 gestational weeks for measurement of RBC and serum total folate, serum unmetabolized FA (UMFA), tetrahydrofolate (THF), 5-methylTHF, 5-formylTHF, 5,10-methenylTHF, and MeFox (pyrazino-s-triazine derivative of 4α-hydroxy-5-methylTHF, a 5-methylTHF oxidation product); total vitamins B-12 and B-6; and plasma total homocysteine. Group differences were determined using χ2, Fisher exact, and Wilcoxon rank-sum tests., Results: Nineteen (38%) women received high-dose FA and 31 (62%) received low-dose FA. The median RBC folate concentration was 2701 (IQR: 2243-3032) nmol/L and did not differ between groups. The high-dose group had higher serum total folate (median: 148.4 nmol/L, IQR: 110.4-181.2; P = 0.007), UMFA (median: 4.6 nmol/L, IQR: 2.5-33.8; P = 0.008), and 5-methylTHF (median: 126.6 nmol/L, IQR: 98.8-158.6; P = 0.03) compared with the low-dose group (median: 122.8 nmol/L, IQR: 99.5-136.0; median: 1.9 nmol/L, IQR: 0.9-4.1; median: 108.6 nmol/L, IQR: 96.4-123.2, respectively). Other biomarkers of 1-carbon metabolism did not differ., Conclusions: High-dose FA supplementation in early pregnancy increases maternal serum folate but not RBC folate concentrations, suggesting tissue saturation. Higher UMFA concentrations in women receiving high-dose FA supplements suggest that these doses are supraphysiologic but with no evidence of altered 1-carbon metabolism., (© Crown copyright 2021.)

We sought to assess chronic inflammatory responses in patients who achieved pregnancy by oocyte donation and non-oocyte donation-assisted reproductive technology and delivered at The Ottawa Hospital. Data describing maternal health, obstetrical outcomes, neonatal outcomes, and placental pathology were collected and analyzed from electronic medical records. An increased frequency of adverse obstetrical outcomes was observed. In the oocyte donation-assisted reproductive technology group, placental pathology data demonstrated increased frequency of fetal vascular malperfusion (p = 0.02) and placenta accreta (p < 0.001), representing a chronic inflammatory response. Placental pathology reflecting dysregulated immune processes and vasculopathy is associated with oocyte donation., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objective: This study sought to assess surgical outcomes of hysterectomy performed for transgender individuals compared with hysterectomy for individuals with menstrual disorders., Methods: This retrospective cohort study was conducted using the American College of Surgeons National Surgical Quality Improvement Program database. Data of transgender individuals who underwent hysterectomy and individuals who underwent hysterectomy for menstrual disorders were extracted from the participant use data file (2015-2016). Transgender individuals were compared with individuals with menstrual disorders for surgical outcomes within 30 days of hysterectomy, by using appropriate statistical tests. A two-sided P value of less than 0.05 was considered statistically significant (Canadian Task Force Classification II-2)., Results: The study identified 89 cases of hysterectomy for transgender individuals and 4439 cases of hysterectomy for menstrual disorders. Compared with patients who underwent hysterectomy for menstrual disorders, transgender patients were more likely to be younger (mean ± SD 30.79 ± 9.68 years vs. 42.6 ± 7.04 years), have a normal body mass index (25.84% vs. 17.77%), be classified as American Society of Anesthesiologists class I (34.09% vs. 10.46%), and have outpatient surgery (76.40% vs. 53.55%) (P < 0.05). Overall incidence of postoperative complications was low for both groups. No significant difference in surgical outcomes was observed for re-admission, superficial or deep/organ space infections, wound dehiscence, sepsis, blood transfusion, deep vein thrombosis, pulmonary embolism, or death. Transgender patients who underwent hysterectomy on average required decreased operative time (120.4 ± 79.2 minutes vs. 131.2 ± 64.3 minutes) and decreased lengths of stay (0.82 ± 0.82 days vs. 1.35 ± 2.73 days)., Conclusion: This study suggests that transgender patients undergoing hysterectomy were younger and healthier than patients undergoing hysterectomy for menstrual disorders. Surgical complications were low for both groups, and significant differences in surgical outcomes were not observed., (Copyright © 2019 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. All rights reserved.)

Objective: To assess the impact of search strategies for a different language on systematic review results, using English index searches versus Chinese index searches for Chinese literature pertaining to cerebral palsy (CP) as an example., Methods: We conducted two parallel searches with the same search strategy. Both searches looked for studies published in the Chinese language that examined risk factors for CP. The first was conducted in standard English indexes and the second was in standard Chinese indexes. We compared the results using the two searches using a Z-test. Egger's test and Begg's test were used to assess the potential publication bias., Results: Using the English indexes, nine studies were identified. Using the identical search and inclusion/exclusion criteria in the Chinese indexes, 17 studies were returned. The association between intracranial hemorrhage and CP was much stronger in the studies found in the search by the English indexes (odds ratio [OR] 61.73, 95% confidence interval (CI) 19.48-195.61) than the results from studies identified by the Chinese indexes (OR 9.57, 95% CI 2.42-37.88). The association between hypertension and CP was not significant in studies found using the English indexes (OR 1.67, 95% CI 0.34-8.30) but was significant in studies identified by searching the Chinese indexes (OR 2.25, 95% CI 1.06-4.77). Egger's test suggested that, for the risk factor of preterm birth, some small studies with negative results might have been missed by the search using the English indexes (Egger's test: P = 0.00)., Conclusions: Searching Chinese literature using English indexes has the potential to fail to identify a substantial number of publications. This bias can result in significant discrepancies in the pooled estimates of risk factors for CP., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objectives: To compare the risk factors for gestational hypertension (GH) and preeclampsia (PE) in the same population, which may provide clues to better understanding of their etiologic mechanisms., Methods: We conducted a cohort study in Liuyang, China, during 2010-2011. Twelve potential risk factors were investigated, including maternal age, body mass index at first antenatal visit, gender of newborn, parity, abortion history, smoking history, family history of hypertension, gestational diabetes mellitus, pregnancy complications of diabetes mellitus/renal disease/cardiac disease, reproductive tract infection, season of delivery, and district level average per capita income. Logistic regression were used to estimate odds ratios for potential risk factors., Results: Of 6223 pregnancies, 1.8% was complicated by PE, and 5.4% by GH. Maternal age older than 35, body mass index above 24, and pregnancy complicated with gestational diabetes mellitus increased the risk of both PE and GH, while with different effect sizes. Primiparity and deliver in winter and spring (compared with summer delivery) were risk factors for GH only. Pregnancy complicated with diabetes mellitus/renal disease/cardiac disease was risk factor for PE only. Significantly lower risk of GH was observed for women younger than 25 or with low body mass index in the first trimester. Mothers carrying a male fetus were more likely to develop PE., Conclusions: Risk factors for GH and PE were not exactly the same. Underling those differences might be their different etiology and mechanism. To confirm the similarities and differences been found in single study, it is important to conduct investigation in other population., (Copyright © 2015 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.)

Background: To explore the impact of passive smoking, cooking with solid fuel, mannose-binding lectin (MBL) gene, MBL-associated serine proteases 2 (MASP-2) gene, and gene-environment interactions on the susceptibility to tuberculosis (TB) in non-smokers., Methods: A total of 205 TB patients and 216 healthy controls were recruited to participate in this case-control study. PCR with sequence-specific primers (PCR-SSP) technology was leveraged to genotype rs7096206 of MBL genes and rs2273346 and rs6695096 of MASP-2 genes. Demographic data and information on exposures of participants were collected. Unconditioned logistic regression analysis was conducted to identify associations between the various factors and TB, and marginal structural linear odds models were used to estimate the interactions., Results: Passive smoking and cooking with solid fuel were associated with the risk of TB, with odds ratios (OR) of 1.58 and 2.93, respectively (p<0.05). Genotype CG at rs7096206 of MBL genes (OR 2.02) and genotype TC at rs6695096 of MASP-2 genes (OR 1.67) were more prevalent in the TB patients than in healthy controls (p<0.05). The relative excess risk of interaction (RERI) between rs7096206 of MBL genes and passive smoking or cooking with solid fuel exposure was 1.86 (95% confidence interval (CI) 0.59-3.16) and 2.66 (95% CI 1.85-3.47), respectively. The RERI between rs6695096 of MASP-2 genes and cooking with solid fuel exposure was 3.70 (95% CI 2.63-4.78), which was also a positive interaction. However, the RERI between rs6695096 of MASP-2 genes and passive smoking was not statistically significant., Conclusions: Passive smoking, cooking with solid fuel, and polymorphisms of MBL (rs7096206) and MASP-2 (rs6695096) genes were associated with susceptibility to TB in non-smokers, and there were gene-environment interactions among them. Further studies are needed to explore details of the mechanisms of association., (Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: To assess whether singleton pregnancies conceived by assisted reproductive technology (ART) are associated with an increased use of intrapartum interventions when compared with spontaneous singleton pregnancies., Methods: In total, 1327 ART pregnancies and 5222 spontaneous pregnancies during the period 2004 to 2008 were extracted from BORN (Better Outcomes Registry and Network) Ontario's information system. The incidences of common intrapartum interventions were compared, and different classification systems for Caesarean section were used to compare the indications for these between singleton pregnancies following ART with or without intracytoplasmic sperm injection and singleton spontaneously conceived pregnancies., Results: Compared with spontaneous singleton pregnancies, the ART group had increased incidences of internal electronic fetal monitoring (OR 1.60; 95% CI 1.37 to 1.87), artificial rupture of membranes (OR 1.39; 95% CI 1.17 to 1.66), oxytocin augmentation of labour (OR 1.51; 95% CI 1.28 to 1.77), induction of labour (OR 1.31; 95% CI 1.14 to 1.50), and Caesarean section (OR 1.40; 95% CI 1.24 to 1.60)., Conclusion: Singleton pregnancies resulting from ART were associated with more frequent use of several intrapartum interventions, including Caesarean section.

Objective: To examine the combined effect of macrosomia and maternal obesity on adverse pregnancy outcomes using a retrospective cohort., Methods: Infants with a birth weight of ≥ 4000g (macrosomia) were identified from an institutional birth cohort. Demographic characteristics and maternal, fetal, neonatal, and pregnancy outcomes of macrosomic infants whose mothers were obese were compared with those whose mothers were non-obese., Results: Pregnancies in obese women resulting in macrosomic infants are more likely to be complicated by gestational diabetes, gestational hypertension, and smoking than pregnancies in non-obese women with macrosomic infants. Mothers whose infants are macrosomic are significantly more likely to require induction of labour (OR 1.42; 95% CI 1.10 to 1.98) and delivery by Caesarean section (OR 1.45; 95% CI 1.04 to 2.01), particularly for maternal indications (OR 3.7; 95% CI 1.47 to 9.34), if they are obese. Finally, macrosomic infants of obese mothers are significantly more likely to require neonatal resuscitation in the form of free flow oxygen (OR 1.57; 95% CI 1.03 to 2.42) than macrosomic infants of non-obese mothers., Conclusion: When both maternal obesity and macrosomia are present, adverse pregnancy outcomes are more common than when fetal macrosomia occurs in a woman of normal weight.

Objective: This study was undertaken to examine the association between maternal oseltamivir treatment for influenza and infant outcomes during the 2009 HINI influenza pandemic., Study Design: This was a retrospective cohort study using a population-based maternal newborn database including women who gave birth to a singleton infant in the Canadian province of Ontario from November 2009 through April 2010. Risks of small for gestational age (SGA) (10th percentile and 3rd percentile), preterm birth (<37 weeks of gestation), very preterm birth (<32 weeks of gestation), and 5-minute Apgar score <7 associated with maternal exposure to oseltamivir were analyzed by multivariable regression., Results: A total of 55,355 women with a singleton birth were included in this study. Among them, 1237 (2.2%) women received oseltamivir for treatment or prevention of influenza during pregnancy. Women who took oseltamivir during pregnancy were less likely to have a SGA infant based on the 10th percentile for growth (adjusted risk ratio, 0.77; 95% confidence interval, 0.60-0.98). No association between maternal use of oseltamivir with SGA on 3rd percentile, preterm birth, very preterm birth, and low Apgar score was observed., Conclusion: There is no evidence of an association between maternal use of oseltamivir for influenza and early birth, low Apgar at birth, and poor fetal growth., (Copyright © 2013 Mosby, Inc. All rights reserved.)

Objective: To calculate the cardiovascular disease (CVD) risk estimates for women following a pregnancy with or without preeclampsia., Methods: We calculated 10-year, 30-year, and lifetime CVD risk estimates at one year postpartum for women recruited into the Pre-Eclampsia New Emerging Team's prospective cohort., Results: Complete CVD risk screening data were obtained from 118 control women and 99 preeclamptic women. A total of 18.2% of preeclamptic women and 1.7% of control women had a high 10-year risk (OR 13.08; 95% CI 3.38 to 85.5), 31.3% of preeclamptic women and 5.1% of control women had a high 30-year risk (OR 8.43; 95% CI 3.48 to 23.23), and 41.4% of preeclamptic women and 17.8% of control women had a high lifetime risk for CVD (OR 3.25; 95% CI 1.76 to 6.11)., Conclusions: The association of preeclampsia with the future development of CVD makes pregnancy an early window of opportunity for the preservation of health and prevention of CVD.

Background: Our goal was to determine the prevalence of metabolic syndrome in women following a pregnancy complicated by preeclampsia and to determine whether this changes between one- and three-years postpartum., Methods: We recruited women into a longitudinal prospective cohort following a pregnancy with or without preeclampsia. The prevalence of cardiometabolic factors were assessed at one- and three-years postpartum. A total of 217 women completed a visit at one year postpartum (n = 99 preeclampsia, n = 118 control subjects) and 120 completed a visit at three-years (n = 73 preeclampsia, n = 47 control subjects)., Results: The prevalence of metabolic syndrome at one- and three-years postpartum was significantly greater in women who had preeclampsia (18.18% at one year, 21.92% at three-years) than in control subjects (6.78%, 6.38%) (P < 0.05), but did not change over time., Conclusions: Given the difficulty in following women long-term, either clinically or as part of study, and because cardiometabolic factors do not change significantly between one- and three-years postpartum, strategies for health preservation and disease prevention should be adopted in the first-year postpartum.

Objective: Carbon monoxide (CO) in cigarette smoke may be the mechanism by which tobacco use during pregnancy decreases the risk of the development of preeclampsia. We attempted to test this hypothesis by examining the effect of maternal exposure to ambient CO on preeclampsia., Study Design: Births that occurred between 2004 and 2009 in the Canadian province of Ontario were extracted from the data. Study subjects were divided into 4 groups according to quartiles of CO concentration that were based on maternal residence. Adjusted odds ratio and 95% confidence interval were used to estimate the independent effect of CO on preeclampsia., Results: Rates of preeclampsia were 2.32%, 1.97%, 1.59%, and 1.26%, respectively, in the first, second, third, and fourth quartile of CO concentration. The inverse association between CO concentration and preeclampsia risk remained the same after adjustment for several important confounding factors., Conclusion: Maternal exposure to moderate ambient CO is associated independently with a decreased risk of preeclampsia., (Crown Copyright © 2012. Published by Mosby, Inc. All rights reserved.)

Objective: The Ottawa and Kingston (OaK) Birth Cohort collected data on maternal and infant genetic and epidemiologic variables in order to (1) explore the association between folate supplementation or thrombophilias and adverse, placenta-mediated pregnancy outcomes; (2) create a biobank of maternal and infant biological and genetic samples; and (3) stimulate future research using this cohort data., Methods: A prospective cohort design was used to collect mother and infant data. Women were recruited at 12 to 20 weeks' gestation, during prenatal care visits at The Ottawa Hospital and Kingston General Hospital from October 2002 to April 2009. Data on maternal and infant demographics, maternal health, obstetrical history, and pregnancy outcomes were collected. Testing was done for biological/serological markers associated with adverse pregnancy outcomes. Maternal and cord blood samples were biobanked., Results: A total of 8085 mothers were recruited to the OaK Birth Cohort. Analysis of the cohort data showed that taking multivitamin supplements containing folic acid was associated with a reduced risk of preeclampsia (aOR 0.37; 95% CI 0.18 to 0.75). The majority of participants agreed to have their genetic/biological samples biobanked (samples collected for n = 7241 mothers, n = 2175 infants) and to be re-contacted regarding future research opportunities., Conclusion: Birth cohorts are a useful tool in determining associations between risk factors and adverse maternal and fetal outcomes, and can serve as a repository of data for future research. Creating strong research partnerships helped enhance financial resources and increase participant recruitment potential. Epidemiological and biobanked data and samples from the OaK Birth Cohort are available for use by other investigators.

Objectives: To determine the factors that put Canadian women at risk for not supplementing with folic acid (FA) in the three months before conception, as recommended for the prevention of infant neural tube defects., Methods: This study used data from the Canadian Maternity Experiences Survey. We used Poisson regression analysis with a robust variance to determine which factors were associated with women not supplementing with FA in the three months prior to pregnancy as compared with women who did supplement., Results: Of the 6421 women surveyed, 57.7% were supplementing with FA pre-conceptionally. The risk factors associated with a lack of FA supplementation pre-conceptionally were maternal age <19 (prevalence ratio [PR] = 0.50; 95% CI 0.36 to 0.69) or 20 to 24 (PR = 0.75; 95% CI 0.67 to 0.84); education below high school level (PR = 0.73; 95% CI 0.61 to 0.87), at high school level (PR = 0.77; 95% CI 0.71 to 0.83), or at post-secondary level other than university (PR = 0.93; 95% CI 0.88 to 0.97); being at or below the low-income cut-off (PR = 0.74; 95% CI 0.67 to 0.81); smoking before pregnancy (PR = 0.79; 95% CI 0.73 to 0.86); being non-fluent in the language of the health care provider (PR = 0.66; 95% CI 0.49 to 0.88); being obese (BMI ≥ 30) (PR = 0.91; 95% CI 0.85 to 0.98); being unemployed (PR = 0.94; 95% CI 0.89 to 1.00); and being born outside of Canada (PR = 0.79; 95% CI 0.74 to 0.84)., Conclusion: Young maternal age, low education, low income, smoking, language barriers, obesity, unemployment, and being born outside Canada are risk factors for suboptimal or lack of FA supplementation pre-conceptionally.

Objective: To examine the association between trimethoprim/sulfamethoxazole, other US Food and Drug Administration (FDA) C and D anti-infectives, and non anti-infective FDA C, D, and X drugs used during pregnancy with preterm birth and low birth weight., Methods: We carried out a retrospective cohort study based on a 50% random sample of women who gave birth in the Canadian province of Saskatchewan from 1997 to 2000. The association between trimethoprim/sulfamethoxazole, other FDA C and D anti-infectives (fluconazole, clarithromycin, doxycycline, and tetracycline), and non anti-infective FDA C, D, and X drugs used during pregnancy with preterm birth and low birth weight was evaluated using multiple logistic regression, with adjusted odds ratios (aORs) and 95% confidence intervals (CIs) as association measures., Results: A total of 17 939 women were included in the final analysis. Trimethoprim/sulfamethoxazole was associated with significantly increased risks for preterm birth (aOR 1.51, 95% CI 1.10, 2.08) and low birth weight (aOR 1.67, 95% CI 1.14, 2.46). Exposure to non anti-infective FDA category C, D and X drugs was also associated with increased risks for preterm birth (aOR 1.17, 95% CI 1.09, 1.31) and low birth weight (aOR 1.14, 95% CI 0.92, 1.42), but to a lesser degree. Other FDA C and D anti-infectives were not (statistically) significantly associated with increased risks for preterm birth (aOR 0.93, 95% CI 0.49, 1.77) or low birth weight (aOR 0.65, 95% CI 0.27, 1.60)., Conclusions: Among FDA C, D and X drugs, trimethoprim/sulfamethoxazole, a folic acid antagonist, has the strongest association with preterm birth and low birth weight., (Copyright © 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Objective: The objective of this study was to determine the cost-effectiveness of using transdermal nitroglycerin (GTN) for cases of preterm labor., Methods: The study included 153 women with clinical preterm labor, who were randomly allocated to either a GTN or placebo arm. All randomized cases were included in the final economic analysis. Differences between the two arms in gestational age at delivery, neonatal intensive care unit (NICU) admission, length of NICU stay, and NICU cost were assessed. Costs for non-NICU cases were calculated using Ottawa Hospital data through the Ontario Case Costing Initiative (OCCI). Cost-effectiveness and sensitivity analyses using a hospital perspective were both conducted., Results: In the 153 randomized cases, 55 babies were admitted to NICU (GTN = 24; placebo = 31). We found no significant differences between the two arms in gestational age at delivery, NICU admission rate (32.4% vs. 39.2%), NICU length of stay (42.7 days vs. 52.8 days), or NICU cost (CAN $34,306 vs. CAN $44,326). Overall, (based on all randomized cases) the cost-effectiveness analyses showed that the GTN arm was the dominant strategy, with both lower cost (CAN $13,397 vs. CAN $18,427) and higher NICU admission avoided rate (67.6% vs. 60.8%) compared to the placebo arm. This dominance persisted in all sensitivity analyses., Conclusion: The use of GTN patch for preterm labor could reduce NICU costs, while improving important neonatal outcomes., (Copyright © 2011 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.)

Objective: Our randomized, double-blind, placebo-controlled trial of transdermal nitroglycerin (GTN) for preterm labour demonstrated a significant reduction in neonatal morbidity and mortality. The objective of this study was to evaluate developmental performance in the children born to women who participated in the GTN trial after one year and two years of follow-up., Methods: The Ages and Stages Questionnaires (ASQ) were used for the assessments, and five domains of child development (communication, gross motor skills, fine motor skills, problem-solving, and personal social skills) were evaluated. Supplementary analyses were performed after stratifying study subjects by gestational age at birth (< 28, 28 to 32, 33 to 36, ≥ 37 weeks) or by defining study subjects as normal or abnormal using standard cut-offs., Results: A total of 153 infants born to women who participated in the GTN trial were included in the initial follow-up. Among them, 111 (72.5%) children (55 in the GTN arm and 56 in the placebo arm) at 12 months of age and 83 (54.2%) children (42 in the GTN arm and 41 in the placebo arm) at 24 months of age completed the full ASQ. There were no differences in ASQ total score and five subscores between the GTN arm and the placebo arm at the one-year and two-year follow-up evaluations, in overall study subjects, or after stratifying study subjects by gestational age. A trend towards reduced abnormalities in the GTN arm at the two-year follow-up was observed, although there was no statistical significance., Conclusion: Maternal GTN use for preterm labour had no impact on children's long-term development, but larger studies are needed to confirm the preliminary findings of this study.

Objective: This secondary analysis of a randomized placebo-controlled trial was to hypothesize on mechanisms for the improved neonatal outcomes with the use of nitroglycerin (GTN) for preterm labor., Study Design: Women in the original trial who delivered at term were excluded. A composite of severe neonatal outcomes, gestational age at delivery, and corticosteroid use in addition to Kaplan-Meier survival analysis to assess time from randomization to delivery were examined., Results: A decrease in composite neonatal outcome (relative risk, 0.21; 95% confidence interval, 0.05-0.81; P = .018) with GTN (n = 39) compared with placebo (n = 38) was primarily due to a 23 day prolongation of pregnancy (P = .019) and a trend (P = .04) toward completing a course of corticosteroids in the subgroup randomized prior to 28 weeks' gestation., Conclusion: We hypothesize that GTN has a gestational age-dependent reduction in neonatal outcomes as a result of pregnancy prolongation and corticosteroid administration., (Copyright © 2010 Mosby, Inc. All rights reserved.)

Objective: to assess the association between neighbourhood family income and adverse birth outcomes., Methods: we conducted a retrospective cohort study of 334 231 singleton births during 2004 and 2006 based on the Niday Perinatal Database from Ontario. Median neighbourhood family incomes from the 2001 Canadian census were linked with the Niday Perinatal Database by dissemination areas. Generalized estimating equations were applied to estimate the odds ratios of adverse birth outcomes associated with lower neighbourhood income, with adjustment for maternal confounding variables at the individual level., Results: compared with the highest neighbourhood income quintile, mothers from the lowest quintile were at increased risk of having small for gestational age neonates (OR 1.51; 95% CI 1.46 to 1.57), low birth weight (OR 1.43; 95% CI 1.36 to 1.50), preterm birth (OR 1.17; 95% CI 1.12 to 1.23), low Apgar score (< 7) at five minutes (OR 1.32; 95% CI 1.21 to 1.44), and stillbirth (OR 1.39; 95% CI 1.19 to 1.62). The risks of women from the lowest income quintiles delivering a macrosomic baby (OR 0.81; 95% CI 0.79 to 0.84) or a large for gestational age baby (OR 0.82; 95% CI 0.80 to 0.85) were significantly decreased. No difference in risk of congenital anomaly was found among different income quintiles., Conclusion: a lower level of neighbourhood income is associated with increased risks of small for gestational age babies, low birth weight, preterm birth, low Apgar score at five minutes, and stillbirth.

Objective: Maternal smoking and preeclampsia independently increase the risk of adverse pregnancy outcomes; however, smoking decreases the risk of preeclampsia. We sought to estimate the risk of adverse pregnancy outcomes among preeclamptic women who smoke and hypothesized that this risk would be increased, compared with nonpreeclamptic women who smoke or preeclamptic women who do not smoke., Study Design: With the use of the Niday Perinatal Database and multiple logistic regressions, we estimated the risk of adverse pregnancy outcomes in nonpreeclamptic women who smoke, preeclamptic women who do not smoke, and preeclamptic women who smoke in relation to nonpreeclamptic women who do not smoke., Results: The incidence of adverse pregnancy outcomes was more than twice as high among preeclamptic women who smoke as among nonpreeclamptic women who do not smoke. The following data were observed: small-for-gestational-age infant (odds ratio [OR], 3.40; 95% CI, 2.27-4.89), preterm birth (OR, 5.77; 95% CI, 4.50-7.35), very preterm birth (OR, 5.44; 95% CI, 3.51-8.11), abruption (OR, 6.16; 95% CI, 3.05-11.01), Apgar <4 at 5 minutes (OR, 3.11; 95% CI, 1.48-5.72), and stillbirth (OR, 3.39; 95% CI, 1.33-6.99)., Conclusion: Smoking decreases the risk of preeclampsia, but smokers with preeclampsia have an increased risk for adverse pregnancy outcomes., (Copyright © 2010 Mosby, Inc. All rights reserved.)

Objective: To assess the trends and determinants of maternal and congenital syphilis in Shanghai, China., Methods: We conducted a prospective cohort study of maternal and congenital syphilis from 2002 to 2006 in Shanghai, China. We presented the trends of maternal syphilis and congenital syphilis rates and compared outcomes in infants born to mothers with complete versus incomplete treatment for maternal syphilis. We also assessed the determinants of compliance to treatment of maternal syphilis and examined the associations of initial maternal RPR antibody level and gestational age at initiation of treatment with occurrence of congenital syphilis., Results: A total of 535 537 pregnant women were included in the analysis. During this period of time, 1471 maternal syphilis cases (298.7 per 100 000 live births) and 334 congenital syphilis cases (62.4 per 100 000 live births) were identified. Both maternal and congenital syphilis rates increased from 2002 until 2005, with a slight decrease in 2006. The rate of maternal syphilis was 156.2 per 100 000 live births in Shanghai residents and 371.7 per 100 000 live births in the migrating population (p<0.001). The compliance to treatment for maternal syphilis was poorer in women with a lower level of education. The rate of congenital syphilis in infants born to mothers with incomplete treatment (50.8%) was much higher than in infants born to mothers with complete treatment (12.5%). Rates of fetal death, neonatal death, and major birth defects were 30.4%, 11.0%, and 3.8%, respectively, in the incomplete treatment group; the corresponding figures were 5.5%, 0.56%, and 0.46%, respectively, in the complete treatment group. Infant outcome was also affected by initial maternal RPR antibody level and time of treatment, with much better outcomes in mothers with low antibody levels and earlier treatment., Conclusion: There has been a resurgence of congenital syphilis in Shanghai, China, especially in the migrating population and other populations with a lower socioeconomic status., (Copyright © 2010 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Objective: We sought to examine the difference in use of labor epidural analgesia among women from different neighborhood socioeconomic groups., Study Design: Neighborhood socioeconomic variables from the 2001 Canadian Census were linked to singleton vaginal births from the Niday perinatal database (2004-2006) in Ontario, Canada. Births were divided into income and education groups by quintiles. Generalized estimating equations were employed to evaluate the association between labor epidural and neighborhood socioeconomic status. Supplementary analysis was conducted after stratifying data by hospital types., Results: Compared with those from the richest neighborhood, women from the poorest quintile were the least likely to receive labor epidural analgesia (odds ratio [OR], 0.59; 95% confidence interval [CI], 0.58-0.61). The differences were smallest in teaching hospitals (OR, 0.73; 95% CI, 0.67-0.79) and largest in small community hospitals (OR, 0.57; 95% CI, 0.50-0.64). Similar association was found in neighborhood education quintiles., Conclusion: The use of labor epidural analgesia is decreased with decreasing neighborhood economic and education levels., (Copyright 2010 Mosby, Inc. All rights reserved.)

Objectives: Hemodialysis-associated bloodstream infection (BSI) is a significant public health problem because the number of hemodialysis patients in Canada had doubled from 1996 to 2005.Our study aimed to determine the costs of nosocomial BSIs in Canada and estimate the investment expenses for establishing infection control programs in general hospitals and conduct cost-benefit analysis., Materials and Methods: The data from the Canadian Nosocomial Infection Surveillance Program was used to estimate the incidence rate of nosocomial BSI. We used Canadian Institute of Health Information data to estimate the extra costs of BSIs per stay across Canada in 2004. The cost of establishing and maintaining an infection control program in 1985 was estimated by the US Centers for Disease Control and Prevention and converted into 2004 Canadian costs. The possible 20% to 30% reduction of total nosocomial BSIs was hypothesized., Results: A total of 2524 hemodialysis-associated BSIs were projected among 15,278 hemodialysis patients in Canada in 2004. The total annual costs to treat BSIs were estimated to be CDN$49.01 million. Total investment costs in prevention and human resources were CDN$8.15 million. The savings of avoidable medical costs after establishing infection control programs were CDN$14.52 million. The benefit/cost ratio was 1.0 to 1.8:1., Conclusion: Our study provides evidence that the economic benefit from implementing infection control programs could be expected to be well in excess of additional cost postinfection if the reduction of BSI can be reduced by 20% to 30%. Infection control offered double benefits: saving money while simultaneously improving the quality of care.

Objective: The aim of this study was to explore the risk factors of schistosomiasis japonica in China, using a hierarchical multi-level model with individuals nested within villages., Methods: A cross-sectional survey of schistosomiasis japonica was conducted in 16 villages in the Chinese province of Hunan. A multi-level modeling technique (HLM version 6.04) was used to assess risk factors of schistosomiasis. The results from this multi-level model were compared with those from a conventional single-level logistic regression model., Results: A total of 10,245 individuals were enrolled in this study, of whom about 4.1% were infected with Schistosoma japonicum. In the multi-level model analysis, individual level variables such as gender, age, and occupation, and village level variables such as type of S. japonicum endemic area, drinking water source, sewage treatment, June temperature, and April rainfall were associated with schistosomiasis japonica infection. Conventional single-level logistic regression analysis selected more independent variables, and had narrower confidence intervals around the corresponding regression coefficients. In particular, per capita income, precipitation in October, and density of infected snails were statistically significant in the conventional single-level logistic regression analysis but not in the multi-level model., Conclusions: Multi-level modeling is a useful tool in the analysis of risk factors of schistosomiasis japonica. Because the multi-level model captures the hierarchical structure of the data, it may be considered a more appropriate analytical tool for data of this type. This technique may also be useful in the analysis of other infectious diseases with a similar hierarchical structure.

Purpose: To assess the association of antenatal and postnatal social support with postpartum depression (PPD)., Methods: We carried out a prospective cohort study of 534 pregnant women between February and September 2007 in Hunan, China. The association between prenatal and postnatal social support with PPD was examined., Results: A total of 103 (19.29%) women had PPD. Women with low prenatal and postnatal social support had higher rates of PPD. For prenatal support, PPD was 28.20% in the lowest quartile versus 9.90% in the highest quartile (adjusted odds ratio [OR]: 3.38, 95% confidence interval [CI]=1.64,6.98). For postnatal support, PPD was 44.10% in the lowest quartile versus 5.40% in the highest quartile (adjusted OR: 9.64, 95% CI=4.09, 22.69)., Conclusions: Lower or lack of social support is a risk factor of PPD. The association between postnatal social support and PPD is much stronger than that of prenatal social support.

Objective: To examine the presence of hepatitis B surface antigen (HBsAg), hepatitis B core antigen (HBcAg), and hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) in renal tissues from patients with HBV-related glomerulonephritis., Methods: Renal tissue biopsies taken from patients with HBV-related glomerulonephritis and two control groups were prepared for immunocytochemical detection of HBsAg and HBcAg. HBV cccDNA was examined using a nested PCR., Results: Of the 63 HBV-related glomerulonephritis patients studied, HBsAg was present in the renal tissues of 48 (76.2%) and HBcAg in the renal tissues of 27 (42.9%). The HBsAg and HBcAg positive rates in HBV-related glomerulonephritis patients were higher than those of the 20 patients with non-HBV-related glomerulonephritis (p<0.05). However, there was no significant difference when the HBV-related glomerulonephritis patients were compared with 12 patients with renal tuberculosis, renal atrophy, renal calculus, and renal tumor with positive serum HBV markers. In patients with HBV-related glomerulonephritis, there was no significant difference in HBsAg and HBcAg positive rates in renal tissue between patients with and without serum hepatitis B e antigen (HBeAg). By nested PCR, two of five patients with HBV-related glomerulonephritis were positive for HBV cccDNA., Conclusion: The location and replication of HBV in renal tissue make the kidney a potential reservoir for HBV. HBV cccDNA may be key in the search for anti-HBV drugs.

Objective: The objective of this study was to prospectively assess physical and biochemical cardiovascular risk markers in women who had developed preeclampsia (PE) at 1 year postpartum., Study Design: Following an overnight fast, previously PE (n = 70) and normotensive women (n = 70) had weight and blood pressure recorded and levels of morning blood for insulin, glucose, C-reactive protein, lipids, cholesterol, and urine for microalbumin and creatinine measured. Body mass index, homeostatic model assessment index, and incidence of metabolic syndrome were determined., Results: At 1 year postpartum, markers of cardiovascular disease were different between the groups. There were also differences in the number of women with abnormal values. Mathematical modeling of cardiovascular event risk suggests that PE increases the risk by 2- to 3-fold; the risk was greatest for women with severe PE., Conclusion: The development of PE is 1 of the earliest clinically identifiable markers of a woman's heightened risk of cardiovascular disease.

Objective: To examine the presence of hepatitis B surface antigen (HBsAg), hepatitis B core antigen (HBcAg), and hepatitis B virus (HBV) DNA in parotid tissues from patients with positive serum HBV markers., Methods: HBsAg and HBcAg were examined in parotid biopsy tissues from patients with suspected parotid tumor and positive serum HBV markers by immunocytochemistry, and HBV DNA was detected in parotid tissues by PCR., Results: Among the 22 patients with a parotid tumor, only one was pathologically confirmed as a neoplasm; all others were benign. HBsAg and HBcAg were present in parotid cells with positive rates of 45.5% (10/22) and 40.9% (9/22), respectively, with an overall positive rate of 54.5% (12/22). Of the 22 cases with serum markers of HBV infection, seven (31.8%) had both HBsAg and HBcAg in the parotid cells. HBV DNA was present in seven of the 12 samples in which hepatitis B antigen was detected (58.3%)., Conclusions: HBV in saliva might originate from the infected salivary glands and the infectious saliva could transmit HBV.

Objective: To determine the potential pathway of the association between teenage pregnancy and neonatal and postneonatal mortality., Study Design and Setting: We carried out a retrospective cohort study of 4,037,009 nulliparous pregnant women under 25 years old who had a live singleton birth during 1995 to 2000, based on linked birth and infant death data set of the United States., Results: Teenage pregnancy (10-19 years old) was associated with increased neonatal mortality (odds ratio [OR]: 1.20, 95% confidence interval [CI]=1.16-1.24) and postneonatal mortality (OR: 1.47, 95% CI=1.41-1.54) after adjustment for potential confounders. With further adjustment for weight gain during pregnancy, teenage pregnancy was still associated with increased risk of neonatal (OR: 1.23, 95% CI=1.19-1.28) and postneonatal mortality (OR: 1.48, 95% CI=1.42-1.55). When adjustment was made for gestational age at birth, there was no association of teenage pregnancy with neonatal mortality (OR: 0.98, 95% CI=0.95-1.02), whereas there was significant association with postneonatal mortality (OR: 1.40, 95% CI=1.34-1.46)., Conclusion: The increased risk of neonatal death associated with teenage pregnancy is largely attributable to higher risk of preterm births, whereas increased postneonatal mortality is independent of the known confounders and gestational age at birth.

Objective: The objective of the study was to evaluate the association between folic acid supplementation in early second trimester and the risk of developing preeclampsia., Study Design: We carried out a prospective cohort study between October 2002-December 2005. We recruited women who had their prenatal care visit (12-20 weeks' gestation) at the Ottawa Hospital and Kingston General Hospital. All charts for participants with a diagnosis of preeclampsia were audited and blindly adjudicated by 4 study investigators to validate the diagnosis., Results: A total of 2951 pregnant women were included in the final analysis. Supplementation of multivitamins containing folic acid was associated with increased serum folate (on average 10.51 micromol/L), decreased plasma homocysteine (on average 0.39 micromol/L), and reduced risk of preeclampsia (adjusted odds ratio, 0.37; 95% confidence interval, 0.18-0.75)., Conclusion: Supplementation of multivitamins containing folic acid in the second trimester is associated with reduced risk of preeclampsia.

Objective: To assess women's satisfaction with the current state of prenatal care for pregnancies complicated by congenital anomalies., Methods: We conducted a cross-sectional survey of 251 women with pregnancies complicated by congenital anomalies. The women were recruited from five Ontario hospitals (Mount Sinai Hospital in Toronto, Hamilton Health Sciences Centre, St. Joseph's Health Care in London, Kingston General Hospital, and The Ottawa Hospital) at the time of referral. A seven-question, self-administered questionnaire developed by an expert panel was used to collect data from the study subjects about satisfaction with prenatal care at antenatal clinics. The women's level of satisfaction was measured using a 5-point scale (1 = least satisfactory and 5 = most satisfactory). Demographic information and information about women's medical and obstetrical history, and obstetrical knowledge was also collected. Descriptive analyses were performed, and relative risks (RR) were calculated to estimate measures of association., Results: Most of the study subjects (> 90%) had a high level of education and were married or in a common-law relationship, and about 80% came from high-income families. The mean age of the study subjects was 31.4 years. The mean gestational age at the first visit with a doctor or midwife was 8.5 weeks, at first being told of a concern with their pregnancy was 18.6 weeks, and at the first visit with an obstetric specialist in the community was 19.6 weeks. Mean scores for each item of satisfaction measure varied from 4.05 to 4.53, and the mean score for women's overall satisfaction was 29.7 (95% confidence intervals [CI] 28.9-30.4). There was a statistically significant association between women's opinion and knowledge of prenatal testing and their level of satisfaction with prenatal care. Women who had difficulty understanding what a doctor or midwife was telling them were less satisfied with prenatal care than women without such difficulty (RR 3.21; 95% CI 2.14-4.81). Language and ethnic diversity were not associated with the level of satisfaction., Conclusion: In Ontario, of women whose pregnancies are complicated by congenital anomalies, those who are less knowledgeable about their pregnancies are more likely to be dissatisfied with their prenatal care. Overall, however, most women are satisfied with their prenatal care.

Objective: The purpose of this study was to identify the gestational age with the lowest morbidity and mortality rates for twin pregnancies that reach term., Study Design: A retrospective cohort study carried out with 60,443 twin pairs from the United States (1995-1997). Analysis was restricted to pregnancies that had reached at least 37 weeks of gestation; groups were created on the basis of the gestational ages of 37, 38, 39, and > or = 40 weeks. The incidence of death and morbidity were calculated; multiple logistic regression models were used to estimate the independent effect of gestational age for twin A and B., Results: The neonatal mortality rate increased significantly after 40 weeks of gestation (twin A: odds ratio, 3.47 [95% CI, 2.29, 5.38]; twin B, odds ratio, 2.52 [95% CI, 1.75, 3.67]). There was also an increased risk of neonatal morbidity in the > or = 40 weeks of gestation group for twin A and B (Apgar score, < or = 3; odds ratio, 1.88 [95% CI, 1.18, 3.02], 1.74 [95% CI, 1.21, 2.52], respectively). There was a decreased risk of assisted ventilation in the 38 and 39 weeks of gestation group for twin A (odds ratio, 0.86 [95% CI, 0.77, 0.97], odds ratio, 0.83 [95% CI, 0.72, 0.95], respectively) and a decreased risk in the 39 and > or = 40 weeks of gestation groups for twin B (assisted ventilation: odds ratio, 0.83 [95% CI, 0.73, 0.93], odds ratio, 0.81 [95% CI, 0.72, 0.92], respectively)., Conclusion: This study suggests that the optimal date of delivery for twins should be <40 weeks of gestation; there was no compelling evidence for delivering at <38 weeks of gestation.

Objective: The purpose of this study was to assess the safety of the use of selective serotonin reuptake inhibitors in pregnancy., Study Design: We carried out a retrospective cohort study of 972 pregnant women who had been given at least 1 selective serotonin reuptake inhibitor prescription in the year before delivery and 3878 pregnant women who did not receive selective serotonin reuptake inhibitors and who were matched by the year of the infant's birth, the type of institute at birth, and the mother's postal code from 1990 to 2000 in the Canadian province of Saskatchewan., Results: The risks of low birth weight (adjusted odds ratio, 1.58; 95% CI, 1.19, 2.11), preterm birth (adjusted odds ratio, 1.57; 95% CI, 1.28, 1.92), fetal death (adjusted odds ratio, 2.23; 95% CI, 1.01, 4.93), and seizures (adjusted odds ratio, 3.87; 95% CI, 1.00, 14.99) were increased in infants who were born to mothers who had received selective serotonin reuptake inhibitor therapy., Conclusion: The use of selective serotonin reuptake inhibitors in pregnancy may increase the risks of low birth weight, preterm birth, fetal death, and seizures.

Previous studies have suggested that environmental lead exposure increases the risk of hypertension in the general population. In this article, the authors used the 1998 linked birth/infant death database of the United States to examine the association between environmental lead level and the occurrence of pregnancy-induced hypertension (PIH). Yearly summaries of environmental lead levels were abstracted from the US Environmental Protection Agency's air pollution databases, and linked with birth/infant death records by state codes. Generalized estimating equations (GEEs) were used to evaluate the odds ratios of PIH associated with environmental lead measured at ecological levels, with adjustment for maternal age, race, education level, marital status, parity, and adequacy of prenatal care measured at individual levels, stratified by maternal cigarette smoking. A total of 2,994,072 women pregnant in 1998 were included in this study. With the first quartile of lead level as the reference group, the odds ratio for PIH among all study subjects in the second quartile of seasonal average lead level at conception was 1.07 (95% CI: 1.05-1.08), and odds ratios in the third and fourth quartiles were 1.22 (95% CI: 1.20-1.25) and 1.16 (95% CI: 1.15-1.18), respectively. The odds ratios for the second, third, and fourth quartiles of seasonal average lead level at birth were 1.07 (95% CI: 1.05-1.09), 1.21 (95% CI: 1.19-1.23), and 1.15 (95% CI: 1.13-1.17), respectively. The risk of PIH increased by 4% per 0.05 microg/m3 increase in seasonal average lead level at conception and birth, in both smokers and nonsmokers. These results suggest that higher environmental lead levels increase the risk of PIH.

Background: Randomized controlled trials have demonstrated that periconceptional folic acid supplementation has a dramatic effect in reducing neural tube defects, one of the most serious congenital anomalies. Unfortunately, supplementation tends to be suboptimal in disadvantaged populations., Objective: The primary objective was to determine patient factors associated with a lack of use of periconceptional folic acid among Canadian women in a multi-ethnic, urban setting. Our secondary objective was to assess patient knowledge about folic acid tablet supplementation and its link to reduced birth defects., Methods: We undertook a cross-sectional study to survey postpartum Toronto women on their use and knowledge of periconceptional folic acid., Results: Of the 383 women surveyed, only 28% took folic acid or a multivitamin containing folic acid during the periconceptional period. Multivariate analysis revealed that the use of periconceptional folic acid was more common among women of Jewish descent (adjusted relative risk [RR] 0.3; 95% confidence interval [CI], 0.04-0.9) and those who had 1 or no children (adjusted RR 0.6; 95% CI, 0.4-0.8). Not taking folic acid was associated with unplanned pregnancy (adjusted RR 1.5; 95% CI, 1.4-1.6) and a lack of knowledge about when folic acid should be taken (adjusted RR 1.8; 95% CI, 1.6-1.8)., Conclusion: Ethnic background is an independent predictor of periconceptional folic acid use.

Objective: The purpose of this study was to assess the risk of neonatal death and morbidity in vertex-nonvertex second twins according to the mode of delivery and birth weight., Study Design: Data from a retrospective cohort study that was based on all twin births in the United States (1995-1997) were used., Results: A total of 15,185 vertex-nonvertex second twins were classified into 3 groups: (1) both twins were delivered by cesarean delivery (37.7%), (2) both twins were delivered vaginally (46.8%), and (3) the second twin was delivered by cesarean delivery after vaginal delivery of the first twin (15.5%). The risk of asphyxia-related neonatal deaths and morbidity was increased in the group in which both twins were delivered vaginally and the group in which both twins were delivered by cesarean delivery. The increase in neonatal death in the group in which both twins were delivered vaginally was stronger in the birth weight of < 1500 g. In contrast, in the group in which both twins were delivered vaginally and the group in which the second twin was delivered by cesarean delivery after the first twin was delivered vaginally, the increase in neonatal morbidity was greater in the group in which the birth weight was 1500 to 4000 g., Conclusion: The risk of neonatal death and morbidity in second-born twins is higher in the group in which both twins were delivered vaginally and the group in which the second twin was delivered by cesarean delivery after the first twin was delivered vaginally compared with the group in which both twins were delivered by cesarean delivery.

Objective: This study was undertaken to estimate occurrence and explore clinical predictors of abdominal and vaginal operative delivery in vertex second twin after normal vaginal delivery of the first twin., Methods: Data from a historical cohort study that was based on a twin registry in the United States (1995-1997) were used., Results: Among 42,417 vertex second twins following normal vaginal delivery of the first twins, rates of abdominal and vaginal operative delivery were 6.3% and 8.3%, respectively. Cord prolapse, fetal distress, maternal complications, abnormal labor, and birth weight 25% larger than first twin were the most important predicators for operative deliveries. Fetal distress and cord prolapse had a stronger effect on abdominal than vaginal operative delivery., Conclusion: In general population, abdominal and vaginal operative delivery rates were 6.3% and 8.3%, respectively, in vertex second twin after normal vaginal delivery of the first twin. The most important predictors for operative delivery are cord prolapse and fetal distress.

Objectives: First, to examine the biological basis of why folic acid may have health effects beyond its proven effect of reducing neural tube defects; and second, to explore current controversial policies of folic acid supplementation and food fortification., Methods: We searched MEDLINE for English-language papers published from 1991 to 2003, using the key words "folic acid" and "folate." The literature search was restricted to human studies. Of 8986 publications identified, 65 were relevant to the objectives of this paper., Results: Analysis of the literature revealed that a major mechanism of folic acid in improving infant health may be related to its effect in correcting maternal folate-homocysteine-methylenetetrahydrofolate reductase metabolic defects. Conversely, exposure to high levels of folic acid may have such adverse health effects as increased risk of neurologic disorders in the general population., Conclusions: Randomized trials or well-designed prospective cohort studies are needed to assess the effects of folic acid on various pregnancy outcomes. To enable an examination of the association between folic acid and rare outcomes, such as a specific category of birth defects and fetal and neonatal deaths, it is necessary to recruit a large number of pregnant women to participate in such studies.

In industrialized countries, 5-11% of infants are born preterm (<37 weeks' gestation), and the rate has been increasing since the early 1980s. Preterm births account for 70% of neonatal deaths and up to 75% of neonatal morbidity, and contribute to long-term neurocognitive deficits, pulmonary dysfunction and ophthalmologic disorders. In the past several decades, major progress has been made in improving the survival of extremely premature newborns, mostly attributable to timely access to effective interventions that ameliorate prematurity-associated mortality and morbidity such as antenatal administration of corticosteroids and exogenous surfactant therapy, rather than preventing preterm births. However, the societal and healthcare costs to care for survivors with severe morbidity and neurological handicaps remain substantial. Future research should concentrate on the ways to reduce long-term health sequelae and developmental handicaps among survivors of infants born preterm, as well as elucidating the mechanisms and aetiology of preterm births.