The use of bubble charts in analyzing second stage cesarean delivery rates.

BACKGROUND: The incidence of second stage cesarean delivery has been rising globally because of the failure or the anticipated difficulty of performing instrumental delivery. Yet, the best way to interpret the figure and its optimal rate remain to be determined. This is because it is strongly influenced by the practice of other 2 modes of birth, namely cesarean delivery performed before reaching the second stage and assisted vaginal birth during the second stage. In this regard, a bubble chart that can display 3-dimensional data through its x-axis, y-axis, and the size of each plot (presented as a bubble) may be a suitable method to evaluate the relationship between the rates of these 3 modes of births. OBJECTIVE: This study aimed to conduct an epidemiologic study on the incidence of second stage cesarean deliveries rates among >300,000 singleton term births in 10 years from 8 obstetrical units and to compare their second stage cesarean delivery rates in relation to their pre-second stage cesarean delivery rates and assisted vaginal birth rates using a bubble chart. STUDY DESIGN: The territory-wide birth data collected between 2009 and 2018 from all 8 public obstetrical units (labelled as A to H) were reviewed. The inclusion criteria were all singleton pregnancies with cephalic presentation that were delivered at term (≥37 weeks' gestation). Pre-second stage cesarean delivery rate was defined as all elective cesarean deliveries and those emergency cesarean deliveries that occurred before full cervical dilatation was achieved as a proportion of the total number of births. The second stage cesarean delivery rate and assisted vaginal birth rate were calculated according to the respective mode of delivery as a proportion of the number of cases that reached full cervical dilatation. The rates of these 3 modes of births were compared among the parity groups and among the 8 units. Using a bubble chart, each unit's second stage cesarean delivery rate (y-axis) was plotted against its pre-second stage cesarean delivery rate (x-axis) as a bubble. Each unit's second stage cesarean delivery to assisted vaginal birth ratio was represented by the size of the bubble. RESULTS: During the study period, a total of 353,434 singleton cephalic presenting term pregnancies were delivered in the 8 units, and 180,496 (51.1%) were from nulliparous mothers. When compared with the multiparous group, the nulliparous group had a significantly lower pre-second stage cesarean delivery rate (18.58% vs 21.26%; P<.001) but a higher second stage cesarean delivery rate (0.79% vs 0.22%; P<.001) and a higher assisted vaginal birth rate (17.61% vs 3.58%; P<.001). Using the bubble of their averages as a reference point in the bubble chart, the 8 units' bubbles were clustered into 5 regions indicating their differences in practice: unit B and unit H were close to the average in the center. Unit A and unit F were at the upper right corner with a higher pre-second stage cesarean delivery rate and second stage cesarean delivery rate. Unit D and unit E were at the opposite end. Unit C was at the upper left corner with a low pre-second stage cesarean delivery rate but a high second stage cesarean delivery rate, whereas unit G was at the opposite end. Unit C and unit G were also in the extremes in terms of pre-second stage cesarean delivery to assisted vaginal birth ratio (0.09 and 0.01, respectively). Although some units seemed to have very similar second stage cesarean delivery rates, their obstetrical practices were differentiated by the bubble chart. CONCLUSION: The second stage cesarean delivery rate must be evaluated in the context of the rates of pre-second stage cesarean delivery and assisted vaginal birth. A bubble chart is a useful method for analyzing the relationship among these 3 variables to differentiate the obstetrical practice between different units.

Perioperative prophylactic internal iliac artery balloon occlusion in the prevention of postpartum hemorrhage in placenta previa: a randomized controlled trial.

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.

Monochorionic twins with selective fetal growth restriction: insight from placental whole-transcriptome analysis.

BACKGROUND: The underlying pathomechanism in placenta-related selective fetal growth restriction in monochorionic diamniotic twin pregnancy is not known. OBJECTIVE: This study aimed to investigate any differences in placental transcriptomic profile between the selectively growth-restricted twins and the normally grown cotwins in monochorionic diamniotic twin pregnancies. STUDY DESIGN: This was a prospective study of monochorionic diamniotic twin pregnancies complicated by selective fetal growth restriction. Placental biopsy specimens were obtained from the subjects in the delivery suite. The placental transcriptome of the selectively growth-restricted twin was compared with that of the normally grown cotwin. This study was divided into 2 stages: (1) gene discovery phase in which placental tissues from 5 monochorionic diamniotic twin pregnancies complicated by selective fetal growth restriction plus 2 control twin pregnancies underwent transcriptome profiling, and transcriptome profiling was carried out using whole-genome RNA sequencing; and (2) validation phase in which placental tissues from 13 monochorionic diamniotic twin pregnancies with selective fetal growth restriction underwent RNA and protein validation. RNA and protein expression levels of candidate genes were determined using quantitative real-time polymerase chain reaction and immunohistochemistry staining. RESULTS: A total of 1429 transcripts were differentially expressed in the placentae of selectively growth-restricted twin pairs, where 610 were up-regulated and 819 were down-regulated. Endoplasmic reticulum lectin and mannose 6-phosphate receptor were consistently differentially up-regulated in all placentae of selectively growth-restricted twins. Quantitative real-time polymerase chain reaction and immunohistochemistry staining were used to validate the results (P<.05). CONCLUSION: The expression of endoplasmic reticulum lectin and mannose 6-phosphate receptor, which are important for angiogenesis and fetal growth, was significantly increased in the placentae of selectively growth-restricted twin of a monochorionic twin pair.

Systematic Selection of Reference Genes for the Normalization of Circulating RNA Transcripts in Pregnant Women Based on RNA-Seq Data.

RNA transcripts circulating in peripheral blood represent an important source of non-invasive biomarkers. To accurately quantify the levels of circulating transcripts, one needs to normalize the data with internal control reference genes, which are detected at relatively constant levels across blood samples. A few reference gene candidates have to be selected from transcriptome data before the validation of their stable expression by reverse-transcription quantitative polymerase chain reaction. However, there is a lack of transcriptome, let alone whole-transcriptome, data from maternal blood. To overcome this shortfall, we performed RNA-sequencing on blood samples from women presenting with preterm labor. The coefficient of variation (CV) of expression levels was calculated. Of 11,215 exons detected in the maternal blood whole-transcriptome, a panel of 395 genes, including PPP1R15B, EXOC8, ACTB, and TPT1, were identified to comprise exons with considerably less variable expression level (CV, 7.75-17.7%) than any GAPDH exon (minimum CV, 27.3%). Upon validation, the selected genes from this panel remained more stably expressed than GAPDH in maternal blood. This panel is over-represented with genes involved with the actin cytoskeleton, macromolecular complex, and integrin signaling. This groundwork provides a starting point for systematically selecting reference gene candidates for normalizing the levels of circulating RNA transcripts in maternal blood.

Patient's choice between a non-invasive prenatal test and invasive prenatal diagnosis based on test accuracy.

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.

The use of bubble charts in analyzing the global second-stage cesarean delivery rates: a systematic review.

OBJECTIVE: This study aimed to systematically review the worldwide second-stage cesarean delivery rate concerning pre-second-stage cesarean delivery and assisted vaginal birth rates. DATA SOURCES: PubMed, Medline Ovid, EBSCOhost, Embase, Scopus, and Google Scholar were queried from inception to February 2023, with the following terms: "full dilatation," "second stage," and "cesarean," with their word variations. Furthermore, an additional cohort of 353,434 cases from our recently published study was included. STUDY ELIGIBILITY CRITERIA: Only original studies that provided sufficient information on the number of pre-second-stage cesarean deliveries, second-stage cesarean deliveries, and vaginal births were included for the calculation of different modes of delivery. Systemic reviews, meta-analyses, or case reports were excluded. METHODS: Study identification and data extraction were independently performed by 2 authors. Selected studies were categorized on the basis of parity, study period, and geographic regions for comparison. RESULTS: A total of 25 studies were included. The overall pre-second-stage cesarean delivery rate, the second-stage cesarean delivery rate, and the second-stage cesarean delivery-to-assisted vaginal birth ratio were 17.94%, 2.65%, and 0.19, respectively. Only 5 studies described singleton, term, cephalic presenting pregnancies of nulliparous women, and their second-stage cesarean delivery rates were significantly higher than those studies with cohorts of all parity groups (4.50% vs 0.83%; P<.05). In addition, the second-stage cesarean delivery rate showed a secular increase across 2009 (0.70% vs 1.05%; P<.05). Moreover, it was the highest among African studies (5.14%) but the lowest among studies from East Asia and South Asia (0.94%). The distributions of second-stage cesarean delivery rates of individual studies and subgroups were shown with that of pre-second-stage cesarean delivery and assisted vaginal birth using the bubble chart. CONCLUSION: The overall worldwide pre-second-stage cesarean delivery rate was 17.94%, the second-stage cesarean delivery rate was 2.65%, and the second-stage cesarean delivery-to-assisted vaginal birth ratio was 0.19. The African studies had the highest second-stage cesarean delivery rate (5.14%) and second-stage cesarean delivery-to-assisted vaginal birth ratio (1.88), whereas the studies from East Asia and South Asia were opposite (0.94% and 0.11, respectively).

Maternal understanding of commercial cord blood storage for their offspring - a survey among pregnant women in Hong Kong.

OBJECTIVE: To assess the knowledge on commercial cord blood banking (CCBB) among pregnant women. DESIGN: Cross-sectional survey. Setting. Antenatal clinics of two major public maternity units in Hong Kong. POPULATION: Pregnant women. METHODS: Self-administered questionnaire. MAIN OUTCOME MEASURES: The survey explored knowledge about the use of self-stored umbilical cord blood (UCB) stem cells and attitude towards CCBB. RESULTS: Of the 2,000 women recruited, 1 866 (93.3%) completed the questionnaire. The majority (78.2%) had no idea that there was the chance of using self-stored stem cells. Moreover, most of the respondents were unclear about which diseases other than leukemia are amenable to treatment with UCB stem cells in general. Only 20.3% of women knew that stem cells are available from the Red Cross in case their children need hematopoietic cell transplantation. CONCLUSIONS: The results of this study revealed inadequate knowledge on UCB stem cell banking and its applications among most of our pregnant women. The government and clinicians should combine efforts to provide accurate information on utilization of UCB stem cells during antenatal care.

Nausea and vomiting in health-related quality of life among Chinese pregnant women.

BACKGROUND: 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. AIMS: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Miscarriage after invasive prenatal diagnostic procedures: how much risk our pregnant women are willing to take?

OBJECTIVES: To elicit the level of risk of prenatal diagnostic procedure-related miscarriage that Chinese pregnant women were willing to accept. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Chinese women's preferences for prenatal diagnostic procedure and their willingness to trade between procedures.

OBJECTIVE: 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. STUDY DESIGN: 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. RESULTS: 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. CONCLUSION: Chinese women showed a strong preference towards performing a full karyotype test and having a full chromosomal assessment performed for their pregnancy.

Soluble fms-like tyrosine kinase-1, placental growth factor and their ratio as a predictor for pre-eclampsia in East Asians.

OBJECTIVE: 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. METHODS: 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. RESULTS: 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 ratio <38 delivered within 7 days, 3 were preterm. Two of the 3 preterm PE pregnancies had sFlt-1MoM:PlGFMoM exceeding 90th percentile. CONCLUSION: 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.

Acceptance towards giving birth to a child with beta-thalassemia major - A prospective study.

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 < 0.05) corresponding to a higher acceptance. During the interview 59.9% participants indicated that they would elect to undergo a termination of pregnancy if their fetus was diagnosed with beta-thalassemia major but 26.5% participants were unable to decide what action they would take. CONCLUSION: Many Chinese pregnant women are ambivalent about giving birth to a baby with beta-thalassemia major. Women with higher educational level or higher family income had a higher acceptance towards the condition.

Deficient knowledge on hepatitis B infection in pregnant women and prevalence of hepatitis B surface antigen carriage in an endemic area: a review.

Hepatitis B infection is a major global health problem. Vertical transmission is the commonest route of spreading hepatitis B virus (HBV) in many endemic areas. In order to control such transmission in Hong Kong, neonatal immunization programme was implemented for more than two decades. A declining prevalence of HBV infection was expected. However, the prevalence remained unabated at around 10% in recent studies. We suspect that one of the explanations of this persistent high prevalence is deficient knowledge on infection with the HBV and its prevention. Our paper gives an overview of the knowledge on HBV infection among Chinese population in both high and low endemic areas and discusses the potential factors that influenced the knowledge on as well as the implication of the sources of information for HBV infection, which was not addressed in previous studies.

Awareness and knowledge of hepatitis B infection and prevention and the use of hepatitis B vaccination in the Hong Kong adult Chinese population.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: This study suggests insufficient public awareness of HBV infection in the Hong Kong Adult Chinese population.

Breastfeeding initiation: is this influenced by maternal hepatitis B infection?

OBJECTIVE: To elucidate the effect of hepatitis B virus (HBV) infection on breastfeeding uptake in Chinese mothers in an endemic region. PATIENTS AND METHODS: 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. RESULTS: 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 (p < 0.001). HBsAg-positive mothers had a significantly lower rate of breastfeeding (39.2 vs. 47.6% p < 0.001). Multiparas had higher incidence of HBV infection (10.9 vs. 9.8%, p < 0.001) and lower breastfeeding rate (42.2% versus 51.0%, p < 0.001) 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). CONCLUSIONS: 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.

Do prior contraceptive methods impact maternal carriage in patients with hepatitis B?

BACKGROUND: Hepatitis B virus (HBV) infection is highly endemic in many Asian countries. OBJECTIVES: We examined whether prior contraceptive methods and sexual behavioral factors impact maternal HBV carriage in an obstetric population. PATIENTS AND METHODS: For this study, pregnant women were considered to be representative of the sexually active and fertile female population. Contraceptive methods used prior to the index pregnancy were examined in 1283 pregnant Chinese women attending an antenatal clinic using a self-administered questionnaire, and correlated with the maternal HBV status determined using routine antenatal screening. RESULTS: In our study, 111 (8.7%) women were infected with HBV and there was no difference in the incidence of male condom usage between HBV-positive (88.3%) and HBV-negative (83.5%) women. No contraceptive method was associated with a reduced incidence of maternal HBV carriage, except for coitus interruptus. In multivariate analysis, only multiparity (adjusted odds ratio [aOR], 1.62) and more than 1 sexual partner (aOR, 1.57) were independent factors associated with maternal HBV carriage. CONCLUSIONS: Contraceptive use played only a minimal role in preventing sexual transmission of HBV infection within the sexually active female population in an endemic area.

Knowledge on hepatitis B infection among pregnant women in a high endemicity area.

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.

Seroprevalence of varicella zoster virus among pregnant women in Hong Kong: comparison with self-reported history.

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.

Outcome of induction of labour using maternal characteristics, ultrasound assessment and biochemical state of the cervix.

OBJECTIVE: To assess pre-induction sonographic, digital examination and biochemical changes in the cervix to predict induction outcome. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Determinants of hepatitis B vaccine uptake among pregnant Chinese women in Hong Kong.

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.