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To assess the clinical utility of the sFlt-1:PlGF ratio rule-in/rule-out pre-eclampsia either directly or after correcting each marker for gestation and maternal weight.This was a prospective cohort study. sFlt-1, PlGF were measured in 965 women randomized to undergo a single blood withdraw between 20 and 39 weeks of gestation. sFlt-1, PlGF and the sFlt-1:PlGF ratio temporal relationship was determined. sFlt-1 and PlGF were converted to multiples of the expected gestational median (MoM) and adjusted for maternal weight. The 90th centile of the adjusted sFlt-1MoM:PlGFMoM ratio was determined. Clinical utility of the sFlt-1:PlGF ratio (≥38) to rule in/rule-out pre-eclampsia (PE) after 20 weeks of gestation versus that of the sFlt-1MoM:PlGFMoM 90th percentile was assessed in 81 women admitted for management of antenatal hypertension.The sFlt-1:PlGF ratio had quadratic relationship with gestation whereas the sFlt-1MoM:PlGFMoM ratio log distribution that was Gaussian with a mean of zero and a standard deviation of 0.85 with a 90th percentile equal to 1.08. Thirty-four (42%) of the 81 women admitted for management of their antenatal hypertension had PE, 26 (76.4%) had a sFlt-1:PlGF ratio ≥ 38. Four of the remaining 8 PE affected pregnancies with sFlt-1:PlGF ratio38 delivered within 7 days, 3 were preterm. Two of the 3 preterm PE pregnancies had sFlt-1MoM:PlGFMoM exceeding 90th percentile.The relative level of the sFlt-1 to PlGF carries prognostic value. A sFlt-1MoM:PlGFMoM ratio exceeding the 90th centile resulted in additional detection of pregnancies which developed PE compared to the conventional sFlt-1:PlGF ratio.

Background Placenta previa remains one of the major causes of massive postpartum hemorrhage and maternal mortality worldwide. Objective To determine whether internal iliac artery balloon occlusion during cesarean delivery for placenta previa could reduce postpartum hemorrhage and other maternal complications. Study Design This was a prospective randomized controlled trial conducted at a tertiary university obstetric unit in Hong Kong. Pregnant women who were diagnosed to have placenta previa at 34 weeks (defined as lower placenta edge within 2 cm from the internal os) and required cesarean delivery were invited to participate. Eligible pregnant women were randomized into internal iliac artery balloon occlusion (Occlusion) group or standard management (Control) group. Those randomized to the Occlusion group had internal iliac artery balloon catheter placement performed before cesarean delivery and then balloon inflation after delivery of the baby. The primary outcome was the reduction of postpartum hemorrhage in those with internal iliac artery balloon occlusion. Secondary outcome measures included hemoglobin drop after delivery; amount of blood product transfusion; incidence of hysterectomy; maternal complications including renal failure, ischemic liver, disseminated intravascular coagulation, and adult respiratory distress syndrome; length of stay in hospital; admission to intensive care unit; and maternal death. Results Between May 2016 and September 2018, 40 women were randomized (20 in each group). Demographic and obstetric characteristics were similar between the 2 groups. In the Occlusion group, 3 women did not receive the scheduled procedure, as it was preceded by antepartum hemorrhage that required emergency cesarean delivery, and 1 woman had repeated scan at 36 weeks showing the placental edge was slightly more than 2 cm from the internal os. Intention-to-treat analysis found no significant differences between the Occlusion and the Control groups regarding to the median intraoperative blood loss (1451 [1024–2388] mL vs 1454 [888–2300] mL; P = .945), the median length of surgery (49 [30–62] min vs 37 [30–51] min; P = .204), or the need for blood transfusion during operation (57.9% vs 50.0%; P = .621). None of the patients had rebleeding after operation, complication related to internal iliac artery procedure, or any other maternal complications. Reanalyzing the data using on-treatment approach showed the same results. Conclusion The use of prophylactic internal iliac artery balloon occlusion in placenta previa patients undergoing cesarean delivery did not reduce postpartum hemorrhage or have any effect on maternal or neonatal morbidity.

Objective: To explore the acceptance of pregnant Chinese women on giving birth to a child with beta-thalassemia major. Materials and methods: Women's acceptance on having a child with beta thalassemia major was assessed using standard gamble metrics during an interviewer-administered survey on 309 women recruited in the antenatal clinic. Utility scores were determined and the association with sociodemographic factors was assessed. Results: The median utility score for having a child with beta-thalassemia major was 0.5 (0–0.65). Women having either higher educational level or family income had significantly higher utility scores (P

To elucidate the effect of hepatitis B virus (HBV) infection on breastfeeding uptake in Chinese mothers in an endemic region.A retrospective cohort study on 63 885 consecutive pregnant delivered between January 1997 and June 2008, were extracted from computerized database to examine the relationship between breastfeeding uptake and maternal HBV status, adjusted for demographic factors.A total of 6593 (10.3%) women were hepatitis B surface antigen (HBsAg)-positive, with an annual prevalence of around 10%. In the study period, 29 869 (46.8%) practised breastfeeding, and its prevalence ranged from 35.4 to 54.8% with an increasing trend throughout the years (p0.001). HBsAg-positive mothers had a significantly lower rate of breastfeeding (39.2 vs. 47.6% p0.001). Multiparas had higher incidence of HBV infection (10.9 vs. 9.8%, p0.001) and lower breastfeeding rate (42.2% versus 51.0%, p0.001) when compared with primiparas. Among those factors, maternal HBV infection had the strongest negative association with breastfeeding (adjusted odd ratio (aOR) = 0.726, 95% confidence interval (CI): 0.689-0.765).Our results suggested maternal HBV infection was one of the factors for the persistently low breastfeeding rate in Hong Kong over the past decades. To promote breastfeeding, it is necessary to generate definitive data on its safety regarding to mother-to-child transmission (MTCT) of HBV in order to allay the fear and anxiety in HBsAg-positive mothers.

Objective To assess the knowledge on hepatitis B virus (HBV) infection and associated factors among expectant mothers in an endemic region. Methods A questionnaire was administered to pregnant Chinese women (n = 1623) attending the antenatal clinic to examine their knowledge on HBV infection, and correlating this with socio-demographic, medical and obstetric factors. Results Independent factors associated with insufficient reduced HBV knowledge include women outside the healthcare sector, lower education level, and no previous HBV testing. The majority of respondents could provide correct responses about the common aspects of HBV infection, including screening, blood-borne and perinatal transmissions, prevention by vaccination, and sequelae of HBV infection, but 47.1% did not know that HBV is transmissible by sexual intercourse. Over 75% respondents misunderstood the fact that HBV cannot be transmitted through food, or prevented by a balanced life style and nutrition. Conclusions Misconceptions about HBV transmission are still common among the obstetric population, and the provision of appropriate and correct information is warranted to improve further the control of HBV infection to the target group. Practice implications Appropriate emphasis should be given to educating the general population about horizontal transmission of HBV.

Hepatitis B virus (HBV) infection is endemic in many countries, but the risk factors for HBV carriage in the obstetric population are unclear. A survey on 1,580 women attending the antenatal clinic in an endemic region was conducted in order to examine the prevalence of and factors associated with maternal HBV carriage, including socio-demographic, medical, and previous obstetrical and family history, by means of a questionnaire. The prevalence of maternal HBV carriage was 9.1%, and 4.8% of women with a history of hepatitis B vaccination were found to be HBV carriers. Factors associated with maternal HBV carriage were residency status (adjusted odds ratio [aOR] 3.65 for immigrants; aOR 7.62 for non-residents), positive family history (aOR 3.72 for infected mother; aOR 5.36 for other family members), no previous vaccination (aOR 4.39) and having previous HBsAg testing (aOR 2.26). The findings suggest that there was probably an overlooked role of horizontal transmission within the family setting in addition to perinatal transmission in determining the likelihood of HBV infection in our obstetric population. Reconfirmation of hepatitis B status might be necessary among individuals with a history of vaccination to ensure the effectiveness of their immunoprotection.

Objectives To determine reference ranges of fetal nasal bone length (NBL) in a Chinese population and to assess the value of NBL measurement in screening for chromosomal defects in the first trimester. Methods In this prospective study the fetal profile was examined and the fetal NBL and crown–rump length (CRL) were measured in Chinese women presenting with singleton pregnancies for first-trimester screening for aneuploidy between January 2004 and June 2007. Screening was performed on the basis of nuchal translucency (NT) measurement and maternal serum free β-human chorionic gonadotropin and pregnancy-associated plasma protein-A levels. Results NBL was measured in 7543 fetuses, of which 7517 were euploid. The best fit equation for median NBL in euploid fetuses in relation to CRL was: NBL (mm) = 0.4593 + (0.0186 × CRL(mm)). The NBL for gestational age (GA, in days) was given by the equation NBL(mm) = 0.2392 + (0.0027 × GA). There was no correlation between log10(NBL multiples of the median (MoM)) and log10(NT MoM) in unaffected pregnancies (r = − 0.009; P = 0.43). Only two of the 11 cases with trisomy 21 had an NBL outside the 5th or 95th centiles of the reference range for euploid fetuses. Conclusion Reference ranges for NBL in a Chinese population suitable for screening for aneuploidy between 11 and 13 + 6 weeks' gestation have been derived. The NBL in Chinese fetuses is similar to that of other ethnic groups. However, unlike the determination of presence vs. absence of the nasal bone, NBL measurement is unlikely to further improve screening for aneuploidy. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.

Objective To determine the prevalence of a history of hepatitis B vaccination among pregnant Chinese women in Hong Kong, and to identify factors associated with vaccine uptake at their own expense. Methods A prospective, cross-sectional survey was conducted in a university obstetric unit in Hong Kong. Pregnant Chinese women who attended the prenatal clinic were invited to complete a self-administered questionnaire, which requested details of their history of hepatitis B vaccination and sociodemographic characteristics. Results The prevalence of hepatitis B vaccine uptake was 33%. The following factors were associated with higher hepatitis B vaccine uptake: employment as a healthcare worker; a higher education level; higher monthly family income; routine medical checkups; and premarital checkups. Conclusion The findings suggest that the public has insufficient awareness of hepatitis B infection in the community and that providing better information and education to the general public is necessary.

Objective To assess the effect of increasing body mass index (BMI) on pregnancy outcome in a population of Chinese women. Design A retrospective study. Setting A university teaching hospital. Population Women delivering singleton babies between 1995 and 2005 who sought antenatal care before 20 weeks of gestation. Methods A total of 29 303 women were categorised into six BMI groups according to WHO’s classification. Univariate, multivariate and logistic regression analysis were performed to compare obstetric and perinatal outcomes between BMI groups. Main outcome measures Incidences of caesarean delivery, pre-eclampsia, gestational diabetes, preterm delivery, small for gestational age (SGA) and large for gestational age (LGA), perinatal death, and the respective odd ratios in reference to the normal group with BMI ≥ 18.5 kg/m2 and

Objective To evaluate expectation and knowledge on obstetric ultrasound examination in the first and second trimester in a Chinese population. Method A cross-sectional survey was conducted in a university obstetric clinic in Hong Kong. Chinese pregnant women who underwent the first trimester early scan sessions, or the second trimester anomaly scan sessions were invited to complete a self-administered questionnaire, which contained items on their knowledge, expectation, and sociodemographic characteristics. Results In all 276 eligible pregnant women (117 in the first trimester and 159 in the second trimester) were recruited. Although 249 women (90.2%) claimed they understood the indication of the ultrasound examination, only 93 of them were correct (33.7%). The median perceived overall-detection rate for structural abnormalities was 66.5%. Living in Hong Kong for more than 7 years was significantly associated with higher knowledge level and expectation from ultrasound examination. Attaining tertiary education level was also significantly associated with higher knowledge level. Over 90% of the pregnant women studied wished to know the fetal gender from the anomaly scan examination. Conclusion Knowledge of Chinese pregnant women on ultrasound was generally unsatisfactory. Understanding their limitation of knowledge and expectations helps to devise appropriate education in the local setting. Copyright © 2008 John Wiley & Sons, Ltd.

Objective To compare seroprevalence (serum IgG titre) with self-reported history of varicella zoster virus (VZV) infection among pregnant women in Hong Kong. Methods Pregnant women undergoing first trimester Down screening over a 3-months period were recruited for the study. Results Positive immunity was found in 477 (95.4%) of the 500 recruited women, and those with positive, negative, or uncertain history of infection had similarly high seroprevalence (96.4, 90.5, 95.9% respectively). The mean age of infection from self-recalled history was 8.61 (SD 4.69) years, and only 3% recalled infection after age 18. Insufficient knowledge on the disease and vaccination was demonstrated. Conclusions Despite the absence of a routine vaccination programme, VZV immunity was high among pregnant women, the majority being infected during childhood and infection above age 18 was very rare. Hence, universal antenatal screening or vaccination for all women in the reproductive age would not be cost-effective in Hong Kong.

Objective: To assess how pregnant women choose between a non-invasive DNA test (NIDT) and an invasive prenatal test (IPD) based on the accuracy of the test. Materials and Methods: Pregnant women who attended for first-trimester combined screening assessment of risk of Down syndrome were invited to participate in an interviewer-administered survey. Women were asked to choose between NIDT (variable detection rate but no miscarriage risk) and IPD (∼100% detection rate but 0.5-1% miscarriage risk) if their screening test was positive for Down syndrome using the standard gamble technique. Results: 358 women were approached of which 106 (29.6%) were unwilling to participate in the study as it had already been decided in advance which additional test they would have if they were screened positive. Of these 106 women, 70 (19.6%) would only choose IPD whereas 36 (10%) would only choose NIDT. Among those who agreed to undertake the gamble and participate in the study (n = 252), 50% were willing to accept NIDT as an alternative to IPD provided that NIDT had a detection rate of 95%. Conclusion: The majority can accept NIDT as an alternative to IPD provided that the test is 95% accurate in the diagnosis of Down syndrome. Current evidence indicates that the detection rate of NIDT will be higher than this level. Health professionals should consider NIDT as an alternative to IPD when counseling women with a positive screening test.

Hepatitis B virus (HBV) infection remains a global public health problem and it is an important cause of acute, chronic and fulminant hepatitis, liver cirrhosis and hepatocellular carcinoma. The prevalence of HBV infection in Hong Kong over the past decade remained unchanged at 10%, despite the implementation of universal neonatal and availability of adult vaccination. We suspect that the current state of affairs is attributable to inadequate awareness and knowledge of HBV transmission and prevention in the general population, resulting in a low rate of uptake of HBV vaccination by the lay public. Therefore, we have embarked in this study to evaluate the awareness and knowledge on HBV infection in our local Chinese population, their attitude on the prevention of horizontal transmission of HBV, and the use of HBV vaccination, especially in those who were born before the era of universal neonatal vaccination.The factors associated with HBV screening, vaccination uptake, and knowledge were examined in a face-to-face questionnaire survey on a group of adult Chinese in Hong Kong.Within this group, 14% was considered to have good knowledge for HBV infection, and 26% had HBV vaccination. Age, occupation, having children, and family monthly income, are independent factors associated with vaccination.This study suggests insufficient public awareness of HBV infection in the Hong Kong Adult Chinese population.

BACKGROUND: Spontaneous preterm birth (SPB, before 37 gestational weeks) is a major cause of perinatal mortality and morbidity, but its pathogenesis remains unclear. Studies on SPB have been hampered by the limited availability of markers for SPB in predelivery clinical samples that can be easily compared with gestational age-matched normal controls. We hypothesize that SPB involves aberrant placental RNA expression, and that such RNA transcripts can be detected in predelivery maternal plasma samples, which can be compared with gestational age-matched controls. PRINCIPAL FINDINGS: Using gene expression microarray to profile essentially all human genes, we observed that 426 probe signals were changed by >2.9-fold in the SPB placentas, compared with the spontaneous term birth (STB) placentas. Among the genes represented by those probes, we observed an over-representation of functions in RNA stabilization, extracellular matrix binding, and acute inflammatory response. Using RT-quantitative PCR, we observed differences in the RNA concentrations of certain genes only between the SPB and STB placentas, but not between the STB and term elective cesarean delivery placentas. Notably, 36 RNA transcripts were observed at placental microarray signals higher than a threshold, which indicated the possibility of their detection in maternal plasma. Among them, the IL1RL1 mRNA was tested in plasma samples taken from 37 women. It was detected in 6 of 10 (60%) plasma samples collected during the presentation of preterm labor (≤32.9 weeks) in women eventually giving SPB, but was detected in only 1 of 27 (4%) samples collected during matched gestational weeks from women with no preterm labor (Fisher exact test, p = 0.00056). CONCLUSION: We have identified 36 SPB-associated RNA transcripts, which are possibly detectable in maternal plasma. We have illustrated that the IL1RL1 mRNA was more frequently detected in predelivery maternal plasma samples collected from women resulting in SPB than the gestational-age matched controls.

Nausea and vomiting in pregnancy (NVP) is the most common pregnancy complication affecting women during the first trimester of pregnancy. The cause of NVP remains unknown and factors associated with the occurrence of NVP are contradictory. There is currently little information on its effects of NVP in general and specifically in the Chinese population.To assess the prevalence of NVP with different degree of severity and identify their relationship with health-related quality of life (HRQoL) and to determine its association with the sociodemographic and obstetric factors.In a prospective cross-sectional study, 396 women who attended the antenatal clinic between 10 and 14 weeks of gestation were invited to complete a structured questionnaire covering maternal characteristics, severity of NVP and their HRQoL. The status of NVP and HRQoL was measured by the frequency of symptoms and the Medical Outcomes Study Short-Form-36 (SF-36) respectively. Logistic regression analysis was performed to delineate the factors associated with NVP.The prevalence of NVP was 90.9%. Almost all domains and dimensions of SF-36 were affected by the presence of NVP and its severity. Factors associated with the presence and severity of NVP were non-smoking, younger age and history of NVP in previous pregnancy.The various degrees of severity of NVP significantly impair both physical and mental HRQoL in Hong Kong Chinese women. Awareness and care should be given to women with symptoms of nausea or retching alone, as well as vomiting.

To assess pre-induction sonographic, digital examination and biochemical changes in the cervix to predict induction outcome.Transvaginal and abdominal scans were performed in 460 women at 37-41 weeks of gestation to determine cervical length (CL), posterior cervical angle (PCA) and foetal occipital position. The Bishop Score (BS) and the absence/presence of phosphorylated form of insulin-like growth factor-binding protein-1 (phIGFBP-1) in cervical secretions were assessed. Independent parameters significantly associated with a vaginal delivery were identified.A total of 340 (73.9%) women achieved a vaginal delivery following induction. Multivariate analysis indicated that significant independent predictors of vaginal delivery were CL (adjusted odds ratio [AOR]: 0.59, 95% confidence interval [CI]: 0.45-0.79), PCA (AOR: 1.89, 95% CI: 1.09-3.28) and multiparae (AOR: 10.02, 95% CI: 5.10-19.69). For a specificity of 75%, the sensitivity for prediction of vaginal delivery using the BS, the CL and the multivariate model using the identified significant independent predictors were 37.1, 46.8 and 68%, respectively.The combination of sonographic assessment of the cervix and maternal characteristics was superior to the either BS or CL alone in the prediction of the induction outcome. Inclusion of the absence/presence of phIGFBP-1 did not further improve induction outcome.

To assess Chinese women's preference for the choice of a prenatal diagnosis test, karyotyping or rapid aneuploidy, and its relationship to maternal psychological state.Three hundred consenting women completed a self administered structured questionnaire which documented their psychological state and their preferred choice of diagnostic test for chromosomal abnormality using a discrete choice experiment design. Diagnostic tests were categorised according to three attributes: completeness of chromosomal information, procedure-to-result time interval and cost.Participants indicated a preference towards the karyotype test irrespective of cost and procedure-to-result time interval. The value of obtaining the extra information provided by karyotyping above that of rapid aneuploidy was pound267.82 (95% CI 226.71-323.31). Women would only accept the rapid aneuploidy test if results where available 18 days sooner than if they were undergoing a karyotyping test. Among women who traded between diagnostic tests, the value of extra chromosomal information was reduced to pound153.83 (95% CI 125.81-192.19). Women with high trait anxiety scores (40) did not preferentially select one test.Chinese women showed a strong preference towards performing a full karyotype test and having a full chromosomal assessment performed for their pregnancy.

To elicit the level of risk of prenatal diagnostic procedure-related miscarriage that Chinese pregnant women were willing to accept.An interviewer-administered survey was conducted on 276 women who presented to the University Obstetric Unit. Using the standard gamble approach, subjects were asked to choose between a screening test with a 90% detection rate and a diagnostic test which is definitive but carries a finite risk of abortion. This probability of abortion was varied until the subject was indifferent between the two choices, and the value was called the utility score.When compared with a screening test with 90% detection rate, the median utility score was 0.989 (IQR: 0.970-0.999). The median risk of abortion below which the subjects would rather opt for an invasive test instead of a screening test was 1.1%. The percentage of patients who could accept a procedure-related miscarriage risk of 0.2, 0.5, 1 and 2% were 76, 67, 59.8 and 38.4%, respectively.Pregnant Chinese women agreed to trade a definitive chromosomal diagnostic test from a highly effective screening test with a small risk of undiagnosed aneuploidy provided that the procedure-related miscarriage risk was 1.1% or lower.

Objectives To develop a sonographic dating formula based on fetal crown–rump length (CRL) in a Hong Kong Chinese population, quantify its systematic prediction error and compare its performance with established dating formulae. Methods This was a prospective observational study of women with a spontaneously conceived singleton pregnancy and a regular menstrual cycle in the preceding 12-month period. Ultrasound examinations were performed at gestational ages ranging from 6 to 15 + 6 weeks according to menstrual dates. The CRL of each fetus was measured three times, the mean of which was used to derive the best-fit fractional polynomial regression model for estimation of gestational age in relation to CRL. For each fetus, the menstrual age was compared to the gestational age calculated using three established dating formulae based on CRL measurement. The mean of the differences between estimated and menstrual age was calculated for each formula. Results Of the 394 subjects recruited one was excluded as the pregnancy resulted in intrauterine demise. The best-fit equation for the sonographic estimate of gestational age (GA, in days) from CRL (in mm) was GA = 26.643 + 7.822 × CRL1/2(R2 = 0.96). The mean difference between menstrual age and the predicted gestational age was 0.22 days (95% CI, − 0.14 to 0.56), which was lower than that of the three established CRL dating formulae. Conclusion We have derived a formula suitable for the dating of naturally conceived pregnancies between 6 and 15 weeks of gestation that has no systematic prediction error (the 95% CI of mean difference between predicted and menstrual age included zero), comparing favorably with established CRL dating formulae. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.