Search

Objective: Accurate assessment of gestational age (GA) is critical to paediatric care, but is limited in developing countries without access to ultrasound. Our objectives were to assess the accuracy of prediction of GA at birth and preterm birth classification using routinely collected anthropometry measures.Design: Prospective cohort study.Setting: United States.Population or Sample: A total of 2334 non-obese and 468 obese pregnant women.Methods: Enrolment GA was determined based on last menstrual period, confirmed by first-trimester ultrasound. Maternal anthropometry and fundal height (FH) were measured by a standardised protocol at study visits; FH alone was additionally abstracted from medical charts. Neonatal anthropometry measurements were obtained at birth. To estimate GA at delivery, we developed three predictor models using longitudinal FH alone and with maternal and neonatal anthropometry. For all predictors, we repeatedly sampled observations to construct training (60%) and test (40%) sets. Linear mixed models incorporated longitudinal maternal anthropometry and a shared parameter model incorporated neonatal anthropometry. We assessed models' accuracy under varied scenarios.Main Outcome Measures: Estimated GA at delivery.Results: Prediction error for various combinations of anthropometric measures ranged between 13.9 and 14.9 days. Longitudinal FH alone predicted GA within 14.9 days with relatively stable prediction errors across individual race/ethnicities [whites (13.9 days), blacks (15.1 days), Hispanics (15.5 days) and Asians (13.1 days)], and correctly identified 75% of preterm births. The model was robust to additional scenarios.Conclusions: In low-risk, non-obese women, longitudinal FH measures alone can provide a reasonably accurate assessment of GA when ultrasound measures are not available.Tweetable Abstract: Longitudinal fundal height alone predicts gestational age at birth when ultrasound measures are unavailable. [ABSTRACT FROM AUTHOR]

Objective: To investigate the independent impact of prepregnancy obesity on preterm delivery among women without chronic diseases by gestational age, preterm category and parity.Design: A retrospective cohort study.Setting: Data from the Consortium on Safe Labor (CSL) in the USA (2002-08).Population: Singleton deliveries at ≥23 weeks of gestation in the CSL (43 200 nulliparas and 63 129 multiparas) with a prepregnancy body mass index (BMI) ≥18.5 kg/m2 and without chronic diseases.Methods: Association of prepregnancy BMI and the risk of preterm delivery was examined using Poisson regression with normal weight as reference.Main Outcome Measures: Preterm deliveries were categorised by gestational age (extremely, very, moderate to late) and category (spontaneous, indicated, no recorded indication).Results: Relative risk of spontaneous preterm delivery was increased for extremely preterm among obese nulliparas (1.26, 95% CI: 0.94-1.70 for overweight; 1.88, 95% CI: 1.30-2.71 for obese class I; 1.99, 95% CI: 1.32-3.01 for obese class II/III) and decreased for moderate to late preterm delivery among overweight and obese multiparas (0.90, 95% CI: 0.83-0.97 for overweight; 0.87, 95% CI: 0.78-0.97 for obese class I; 0.79, 95% CI: 0.69-0.90 for obese class II/III). Indicated preterm delivery risk was increased with prepregnancy BMI in a dose-response manner for extremely preterm and moderate to late preterm among nulliparas, as it was for moderate to late preterm delivery among multiparas.Conclusions: Prepregnancy BMI was associated with increased risk of preterm delivery even in the absence of chronic diseases, but the association was heterogeneous by preterm categories, gestational age and parity.Tweetable Abstract: Obese nulliparas without chronic disease had higher risk for spontaneous delivery <28 weeks of gestation. [ABSTRACT FROM AUTHOR]

Objective: To assess differences in small-for-gestational age (SGA) classifications for the detection of neonates with increased perinatal mortality risk among obese women and subsequently assess the association between prepregnancy body mass index (BMI) status and SGA.Design: Hospital-based cohort.Setting: Twelve US clinical centres (2002-08).Population: A total of 114 626 singleton, nonanomalous pregnancies.Methods: Data were collected using electronic medical record abstraction. Relative risks (RR) with 95% CI were estimated.Main Outcome Measures: SGA trends (birthweight < 10th centile) classified using population-based (SGAPOP ), intrauterine (SGAIU ) and customised (SGACUST ) references were assessed. The SGA-associated perinatal mortality risk was estimated among obese women. Using the SGA method most associated with perinatal mortality, the association between prepregnancy BMI and SGA was estimated.Results: The overall perinatal mortality prevalence was 0.55% and this increased significantly with increasing BMI (P < 0.01). Among obese women, SGAIU detected the highest proportion of perinatal mortality cases (2.49%). Perinatal mortality was 5.32 times (95% CI 3.72-7.60) more likely among SGAIU neonates than non-SGAIU neonates. This is in comparison with the 3.71-fold (2.49-5.53) and 4.81-fold (3.41-6.80) increased risk observed when SGAPOP and SGACUST were used, respectively. Compared with women of normal weight, overweight women (RR = 0.82, 95% CI 0.78-0.86) and obese women (RR = 0.80; 95% CI 0.75-0.83) had a lower risk for delivering an SGAIU neonate.Conclusion: Among obese women, the intrauterine reference best identified neonates at risk of perinatal mortality. Based on SGAIU , SGA is less common among obese women but these SGA babies are at a high risk of death and remain an important group for surveillance.Tweetable Abstract: SGA is less common among obese women but these SGA babies are at a high risk of death. [ABSTRACT FROM AUTHOR]

Objectives: To estimate the incidence and risk of complications associated with a fetal scalp electrode and to determine whether its application in the setting of operative vaginal delivery was associated with increased neonatal morbidity.Design: Retrospective cohort study.Setting: Twelve clinical centers with 19 hospitals across nine American Congress of Obstetricians and Gynecologists US districts.Population: Women in the USA.Methods: We evaluated 171 698 women with singleton deliveries ≥ 23 weeks of gestation in a secondary analysis of the Consortium on Safe Labor study between 2002 and 2008, after excluding conditions that precluded fetal scalp electrode application such as prelabour caesarean delivery. Secondary analysis limited to operative vaginal deliveries ≥ 34 weeks of gestation was also performed.Main Outcome Measures: Incidences and adjusted odds ratios with 95% confidence intervals of neonatal complications were calculated, controlling for maternal characteristics, delivery mode and pregnancy complications.Results: Fetal scalp electrode was used in 37 492 (22%) of deliveries. In non-operative vaginal delivery, fetal scalp electrode was associated with increased risk of injury to scalp due to birth trauma (1.2% versus 0.9%; adjusted odds ratios 1.62; 95% confidence intervals 1.41-1.86) and cephalohaematoma (1.0% versus 0.9%; adjusted odds ratios 1.57; 95% confidence intervals 1.36-1.83). Neonatal complications were not significantly different comparing fetal scalp electrode with vacuum-assisted vaginal delivery and vacuum-assisted vaginal delivery alone or comparing fetal scalp electrode with forceps-assisted vaginal delivery and forceps-assisted vaginal delivery alone.Conclusions: We found increased neonatal morbidity with fetal scalp electrode though the absolute risk was very low. It is possible that these findings reflect an underlying indication for its use. Our findings support the use of fetal scalp electrodes when clinically indicated.Tweetable Abstract: Neonatal risks associated with fetal scalp electrode use were low (injury to scalp 1.2% and cephalohaematoma 1.0%). [ABSTRACT FROM AUTHOR]

Background: The COVID-19 pandemic may have disproportionally impacted vulnerable groups such as people who inject drugs (PWID) through reduced healthcare services as well as social changes from pandemic mitigation measures. Understanding how the COVID-19 pandemic and associated mitigation strategies subsequently changed the trajectory of hepatitis C virus (HCV) and HIV transmission is critical to estimating disease burdens, identifying outbreak risk, and developing informed intervention strategies., Methods: Using behavioral data from the AIDS Linked to the IntraVenous Experience (ALIVE) study, an ongoing community-based cohort of PWID in Baltimore, USA, and an individual-based network model, we explored the impacts of service disruptions combined with changes in social networks and injecting behaviors of PWID on HCV and HIV transmission., Results: Analyses of ALIVE data showed that during the pandemic, there was an acceleration in injection cessation trajectories overall, but those who continued injecting increased the frequency of injection; at the same time, individual drug-use networks became smaller and the probability of injecting with others decreased. Simulation results demonstrated that HCV and HIV prevalence increased from service disruptions alone, but these effects were mitigated when including observed behavior changes in addition., Conclusions: Model results combined with rich individual behavioral data indicated that pandemic-induced behavioral changes of PWID that lasted longer than service disruptions could have offset the increasing disease burden caused by disrupted service access during the pandemic., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Introduction: Adverse pregnancy outcomes such as preterm delivery and preeclampsia are associated with a higher maternal risk for subsequent cardiovascular disease (CVD) and all-cause mortality. While such pregnancy conditions are related to abnormal placentation, little research has investigated whether pathologic placental measures could serve as a risk factor for future CVD mortality in mothers., Methods: Longitudinal study of 33,336 women from the Collaborative Perinatal Project (CPP; 1959-1966) linked to mortality information through December 2016. Pathologists took extensive morphological and histopathological measures. Apart from assessing associations with morphological features, we derived an overall composite score and specific inflammation-related, hemorrhage-related, and hypoxia-related pathologic placenta index scores. Cox regression estimated hazard ratios (HR) and 95% confidence intervals (CI) for mortality adjusting for covariates., Results: Thirty-nine percent of women died with mean (standard deviation, SD) time to death of 39 (12) years. Mean (SD) placental weight and birthweight were 436 g (98) and 3156 g (566), respectively. Placenta-to-birthweight ratio was associated with all-cause mortality (adjusted HR 1.03: 1.01, 1.05 per SD in ratio). In cause-specific analyses, it was significantly associated with respiratory (HR 1.06), dementia (HR: 1.10) and liver (HR 1.04) related deaths. CVD, cancer, diabetes and kidney related deaths also tended to increase, whereas infection related deaths did not (HR 0.94; 0.83, 1.06). Placental measures of thickness, diameters, and histopathological measures grouped by inflammatory, hemorrhagic, or hypoxic etiology were not associated with mortality., Discussion: Placental weight in relation to birthweight was associated with long-term maternal mortality but other histopathologic or morphologic features were not., (Copyright © 2021. Published by Elsevier Ltd.)

Background: Information on the etiology and age-specific burden of respiratory viral infections among school-aged children remains limited. Though school aged children are often recognized as driving the transmission of influenza as well as other respiratory viruses, little detailed information is available on the distribution of respiratory infections among children of different ages within this group. Factors other than age including gender and time spent in school may also be important in determining risk of infection but have been little studied in this age group., Methods: We conducted a cohort study to determine the etiology of influenza like illness (ILI) among 2519 K-12 students during the 2012-13 influenza season. We obtained nasal swabs from students with ILI-related absences. Generalized linear mixed-effect regressions determined associations of outcomes, including ILI and laboratory-confirmed respiratory virus infection, with school grade and other covariates., Results: Overall, 459 swabs were obtained from 552 ILI-related absences. Respiratory viruses were found in 292 (63.6%) samples. Influenza was found in 189 (41.2%) samples. With influenza B found in 134 (70.9%). Rates of influenza B were significantly higher in grades 1 (10.1, 95% CI 6.8-14.4%), 2 (9.7, 6.6-13.6%), 3 (9.3, 6.3-13.2%), and 4 (9.9, 6.8-13.8%) than in kindergarteners (3.2, 1.5-6.0%). After accounting for grade, sex and self-reported vaccination status, influenza B infection risk was lower among kindergarteners in half-day programs compared to kindergarteners in full-day programs (OR = 0.19; 95% CI 0.08-0.45)., Conclusions: ILI and influenza infection is concentrated in younger schoolchildren. Reduced infection by respiratory viruses is associated with a truncated school day for kindergarteners but this finding requires further investigation in other grades and populations.

Since the 2000s, air pollution has generally continued to decrease in the U.S. To investigate preterm birth (PTB) risk associated with air pollutants in two consecutive pregnancies, we estimated exposures using modified Community Multiscale Air Quality models linked to the NICHD Consecutive Pregnancy Study. Electronic medical records for delivery admissions were available for 50,005 women with singleton births in 20 Utah-based hospitals between 2002-2010. We categorized whole pregnancy average exposures as high (>75th percentile), moderate (25-75) and low (<25). Modified Poisson regression estimated second pregnancy PTB risk associated with persistent high and moderate exposure, and increasing or decreasing exposure, compared to persistent low exposure. Analyses were adjusted for prior PTB, interpregnancy interval and demographic and clinical characteristics. Second pregnancy PTB risk was increased when exposure stayed high for sulfur dioxide (32%), ozone (17%), nitrogen oxides (24%), nitrogen dioxide (43%), carbon monoxide (31%) and for particles < 10 microns (29%) versus consistently low exposure. PTB risk tended to increase to a lesser extent for repeated PTB (19-21%) than for women without a prior PTB (22-79%) when exposure increased or stayed high. Area-level changes in air pollution exposure appear to have important consequences in consecutive pregnancies with increasing exposure associated with higher risk.

Background: The impact of autoimmune diseases on pregnancy remains understudied on a population level. Examination of obstetric and neonatal outcomes among women with autoimmune disease and their infants can provide important insights for clinical management., Methods: Autoimmune diseases and outcomes were identified using medical records. Cesarean delivery, preterm birth, preeclampsia, small for gestational age (SGA), neonatal intensive care (NICU) admission, neonatal respiratory distress syndrome (RDS), and perinatal mortality risk was assessed. Poisson regression with robust standard errors estimated relative risks (RR) and 95% confidence intervals (95% CI) with adjustment for maternal characteristics and other chronic conditions., Results: Women with T1DM were at increased risk for nearly all outcomes including RDS (RR: 3.62; 95% CI: 2.84, 4.62), perinatal mortality (RR: 2.35; 95% CI: 1.12, 4.91), cesarean delivery (RR: 2.16; 95% CI: 2.02, 2.32) and preterm birth (RR: 3.52; 95% CI: 3.17, 3.91). Women with SLE also had higher risk for preterm delivery (RR: 2.90; 95% CI: 2.42, 3.48) and RDS (RR:2.99; 95% CI: 1.99, 4.51) as did women with Crohn's (cesarean delivery RR:1.31, 95% CI: 1.08, 1.60; preterm delivery RR: 1.84, 95% CI: 1.37, 2.49. RA increased risk for SGA (RR:1.66; 95% CI: 1.08, 2.55)., Conclusion(s): Despite the heterogeneity in autoimmune diseases, we observed elevated preterm birth risk for most women with autoimmune disease. SLE and T1DM appeared to confer increased risk for a wide range of adverse outcomes., (Published by Elsevier Ltd.)

Objective: Accurate assessment of gestational age (GA) is critical to paediatric care, but is limited in developing countries without access to ultrasound. Our objectives were to assess the accuracy of prediction of GA at birth and preterm birth classification using routinely collected anthropometry measures., Design: Prospective cohort study., Setting: United States., Population or Sample: A total of 2334 non-obese and 468 obese pregnant women., Methods: Enrolment GA was determined based on last menstrual period, confirmed by first-trimester ultrasound. Maternal anthropometry and fundal height (FH) were measured by a standardised protocol at study visits; FH alone was additionally abstracted from medical charts. Neonatal anthropometry measurements were obtained at birth. To estimate GA at delivery, we developed three predictor models using longitudinal FH alone and with maternal and neonatal anthropometry. For all predictors, we repeatedly sampled observations to construct training (60%) and test (40%) sets. Linear mixed models incorporated longitudinal maternal anthropometry and a shared parameter model incorporated neonatal anthropometry. We assessed models' accuracy under varied scenarios., Main Outcome Measures: Estimated GA at delivery., Results: Prediction error for various combinations of anthropometric measures ranged between 13.9 and 14.9 days. Longitudinal FH alone predicted GA within 14.9 days with relatively stable prediction errors across individual race/ethnicities [whites (13.9 days), blacks (15.1 days), Hispanics (15.5 days) and Asians (13.1 days)], and correctly identified 75% of preterm births. The model was robust to additional scenarios., Conclusions: In low-risk, non-obese women, longitudinal FH measures alone can provide a reasonably accurate assessment of GA when ultrasound measures are not available., Tweetable Abstract: Longitudinal fundal height alone predicts gestational age at birth when ultrasound measures are unavailable., (© 2018 Royal College of Obstetricians and Gynaecologists.)

Iodine 131 (I-131), the principal component of nuclear fallout from the Chernobyl accident, concentrates in the thyroid gland and may pose risks to fetal development. To evaluate this, neonatal outcomes following the accident in April of 1986 were investigated in a cohort of 2582 in utero-exposed individuals from northern Ukraine for whom estimates of fetal thyroid I-131 dose were available. We carried out a retrospective review of cohort members' prenatal, delivery and newborn records. The relationships of dose with neonatal anthropometrics and gestational length were modeled via linear regression with adjustment for potentially confounding variables. We found similar, statistically significant dose-dependent reductions in both head circumference (-1.0 cm/Gy, P = 0.005) and chest circumference (-0.9 cm/Gy, P = 0.023), as well as a similar but non-significant reduction in neonatal length (-0.6 cm/Gy, P = 0.169). Gestational length was significantly increased with increasing fetal dose (0.5 wks/Gy, P = 0.007). There was no significant (P > 0.1) effect of fetal dose on birth weight. The observed associations of radioiodine exposure with decreased head and chest circumference are consistent with those observed in the Japanese in utero-exposed atomic bomb survivors.

Objective: To investigate the independent impact of prepregnancy obesity on preterm delivery among women without chronic diseases by gestational age, preterm category and parity., Design: A retrospective cohort study., Setting: Data from the Consortium on Safe Labor (CSL) in the USA (2002-08)., Population: Singleton deliveries at ≥23 weeks of gestation in the CSL (43 200 nulliparas and 63 129 multiparas) with a prepregnancy body mass index (BMI) ≥18.5 kg/m 2 and without chronic diseases., Methods: Association of prepregnancy BMI and the risk of preterm delivery was examined using Poisson regression with normal weight as reference., Main Outcome Measures: Preterm deliveries were categorised by gestational age (extremely, very, moderate to late) and category (spontaneous, indicated, no recorded indication)., Results: Relative risk of spontaneous preterm delivery was increased for extremely preterm among obese nulliparas (1.26, 95% CI: 0.94-1.70 for overweight; 1.88, 95% CI: 1.30-2.71 for obese class I; 1.99, 95% CI: 1.32-3.01 for obese class II/III) and decreased for moderate to late preterm delivery among overweight and obese multiparas (0.90, 95% CI: 0.83-0.97 for overweight; 0.87, 95% CI: 0.78-0.97 for obese class I; 0.79, 95% CI: 0.69-0.90 for obese class II/III). Indicated preterm delivery risk was increased with prepregnancy BMI in a dose-response manner for extremely preterm and moderate to late preterm among nulliparas, as it was for moderate to late preterm delivery among multiparas., Conclusions: Prepregnancy BMI was associated with increased risk of preterm delivery even in the absence of chronic diseases, but the association was heterogeneous by preterm categories, gestational age and parity., Tweetable Abstract: Obese nulliparas without chronic disease had higher risk for spontaneous delivery <28 weeks of gestation., (© 2017 Royal College of Obstetricians and Gynaecologists.)

Objective: To assess differences in small-for-gestational age (SGA) classifications for the detection of neonates with increased perinatal mortality risk among obese women and subsequently assess the association between prepregnancy body mass index (BMI) status and SGA., Design: Hospital-based cohort., Setting: Twelve US clinical centres (2002-08)., Population: A total of 114 626 singleton, nonanomalous pregnancies., Methods: Data were collected using electronic medical record abstraction. Relative risks (RR) with 95% CI were estimated., Main Outcome Measures: SGA trends (birthweight < 10th centile) classified using population-based (SGA POP ), intrauterine (SGA IU ) and customised (SGA CUST ) references were assessed. The SGA-associated perinatal mortality risk was estimated among obese women. Using the SGA method most associated with perinatal mortality, the association between prepregnancy BMI and SGA was estimated., Results: The overall perinatal mortality prevalence was 0.55% and this increased significantly with increasing BMI (P < 0.01). Among obese women, SGA IU detected the highest proportion of perinatal mortality cases (2.49%). Perinatal mortality was 5.32 times (95% CI 3.72-7.60) more likely among SGA IU neonates than non-SGA IU neonates. This is in comparison with the 3.71-fold (2.49-5.53) and 4.81-fold (3.41-6.80) increased risk observed when SGA POP and SGA CUST were used, respectively. Compared with women of normal weight, overweight women (RR = 0.82, 95% CI 0.78-0.86) and obese women (RR = 0.80; 95% CI 0.75-0.83) had a lower risk for delivering an SGA IU neonate., Conclusion: Among obese women, the intrauterine reference best identified neonates at risk of perinatal mortality. Based on SGA IU , SGA is less common among obese women but these SGA babies are at a high risk of death and remain an important group for surveillance., Tweetable Abstract: SGA is less common among obese women but these SGA babies are at a high risk of death., (Published 2016. This article is a U.S. Government work and is in the public domain in the USA.)

Objectives: To estimate the incidence and risk of complications associated with a fetal scalp electrode and to determine whether its application in the setting of operative vaginal delivery was associated with increased neonatal morbidity., Design: Retrospective cohort study., Setting: Twelve clinical centers with 19 hospitals across nine American Congress of Obstetricians and Gynecologists US districts., Population: Women in the USA., Methods: We evaluated 171 698 women with singleton deliveries ≥ 23 weeks of gestation in a secondary analysis of the Consortium on Safe Labor study between 2002 and 2008, after excluding conditions that precluded fetal scalp electrode application such as prelabour caesarean delivery. Secondary analysis limited to operative vaginal deliveries ≥ 34 weeks of gestation was also performed., Main Outcome Measures: Incidences and adjusted odds ratios with 95% confidence intervals of neonatal complications were calculated, controlling for maternal characteristics, delivery mode and pregnancy complications., Results: Fetal scalp electrode was used in 37 492 (22%) of deliveries. In non-operative vaginal delivery, fetal scalp electrode was associated with increased risk of injury to scalp due to birth trauma (1.2% versus 0.9%; adjusted odds ratios 1.62; 95% confidence intervals 1.41-1.86) and cephalohaematoma (1.0% versus 0.9%; adjusted odds ratios 1.57; 95% confidence intervals 1.36-1.83). Neonatal complications were not significantly different comparing fetal scalp electrode with vacuum-assisted vaginal delivery and vacuum-assisted vaginal delivery alone or comparing fetal scalp electrode with forceps-assisted vaginal delivery and forceps-assisted vaginal delivery alone., Conclusions: We found increased neonatal morbidity with fetal scalp electrode though the absolute risk was very low. It is possible that these findings reflect an underlying indication for its use. Our findings support the use of fetal scalp electrodes when clinically indicated., Tweetable Abstract: Neonatal risks associated with fetal scalp electrode use were low (injury to scalp 1.2% and cephalohaematoma 1.0%)., Competing Interests: of interest: The authors report no conflicts of interest. The ICMJE disclosure forms are available as online supporting information., (© 2015 Royal College of Obstetricians and Gynaecologists.)

First discovered in 1947, Zika virus (ZIKV) infection remained a little-known tropical disease until 2015, when its apparent association with a considerable increase in the incidence of microcephaly in Brazil raised alarms worldwide. There is limited information on the key factors that determine the extent of the global threat from ZIKV infection and resulting complications. Here, we review what is known about the epidemiology, natural history, and public health effects of ZIKV infection, the empirical basis for this knowledge, and the critical knowledge gaps that need to be filled., (Copyright © 2016, American Association for the Advancement of Science.)

Objective: To study the relationship between acute air pollution exposure and cardiovascular events during labour/delivery., Methods: The Consortium on Safe Labor (2002-2008), an observational US cohort with 223,502 singleton deliveries provided electronic medical records. Air pollution exposure was estimated by modified Community Multiscale Air Quality models. Cardiovascular events (cardiac failure/arrest, stroke, myocardial infarcts and other events) were recorded in the hospital discharge records for 687 pregnancies (0.3%). Logistic regression with generalised estimating equations estimated the relationship between cardiovascular events and daily air pollutant levels for delivery day and the 7 days preceding delivery., Results: Increased odds of cardiovascular events were observed for each IQR increase in exposure to nitric oxides at 5 and 6 days prior to delivery (OR=1.17, 99% CI 1.04 to 1.30 and OR=1.15, 1.03 to 1.28, respectively). High exposure to toxic air pollution species such as ethylbenzene (OR=1.50, 1.08 to 2.09), m-xylene (OR=1.54, 1.11 to 2.13), o-xylene (OR=1.51, 1.09 to 2.09), p-xylene (OR=1.43, 1.03 to 1.99) and toluene (OR=1.42, 1.02 to 1.97) at 5 days prior to delivery were also associated with cardiovascular events. Decreased odds of events were observed with exposure to ozone., Conclusions: Air pollution in the days prior to delivery, especially nitrogen oxides and some toxic air pollution species, was associated with increased risk of cardiovascular events during the labour/delivery admission., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Purpose: To examine whether maternal asthma contributes to racial/ethnic differences in obstetrical and neonatal complications., Methods: Data on white (n = 110,603), black (n = 50,284), and Hispanic (n = 38,831) singleton deliveries came from the Consortium on Safe Labor. Multilevel logistic regression models, with an interaction term for asthma and race/ethnicity, estimated within-group adjusted odds ratios (aORs) for gestational diabetes, gestational hypertension, pre-eclampsia, placental abruption, premature rupture of membranes, preterm delivery, maternal hemorrhage, neonatal intensive care unit admissions, small for gestational age, apnea, respiratory distress syndrome, transient tachypnea of the newborn, anemia, and hyperbilirubinemia after adjustment for clinical and demographic confounders. Nonasthmatics of the same racial/ethnic group were the reference group., Results: Compared with nonasthmatics, white asthmatics had increased odds of pre-eclampsia (aOR, 1.28; 95% confidence interval [CI], 1.15-1.43) and maternal hemorrhage (aOR, 1.14; 95% CI, 1.04-1.23). White and Hispanic infants were more likely to have neonatal intensive care unit admissions (aOR, 1.19; 95% CI, 1.11-1.28; aOR, 1.16; 95% CI, 1.02-1.32, respectively) and be small for gestational age (aOR, 1.11; 95% CI, 1.02-1.20; aOR, 1.26; 95% CI, 1.10-1.44, respectively), and Hispanic infants were more likely to have apnea (aOR, 1.32; 95% CI, 1.02-1.69)., Conclusions: Maternal asthma did not affect most obstetrical and neonatal complication risks within racial/ethnic groups. Despite their increased risk for both asthma and many complications, our findings for black women were null. Asthma did not contribute to racial/ethnic disparities in complications., (Published by Elsevier Inc.)