Patient acceptance of transvaginal sonographic endometrial thickness assessment compared with hysteroscopy and biopsy for exclusion of endometrial cancer in cases of postmenopausal bleeding.

INTRODUCTION: Available examinations for women with postmenopausal bleeding include transvaginal sonography to measure endometrial thickness (TVS-ET), and invasive endometrial assessment using hysteroscopy/endometrial biopsy. However, selection of the examination method seldom involves consideration of patient preferences. The aim of this study was to examine patient preferences for the method used to investigate postmenopausal bleeding. METHODS: Women were asked to complete an interviewer-administered structured survey before they underwent clinical investigations at a university gynaecology unit from June 2016 to June 2017. Using the standard gamble approach, women were asked to choose between invasive assessment by hysteroscopy/endometrial biopsy (gold standard) or TVS-ET with a risk of missing endometrial cancer. The risk of missing endometrial cancer during TVS-ET was varied until each woman was indifferent to either option. RESULTS: The median detection rate for endometrial cancer required using TVS-ET was 95% (interquartile range=80%-99.9%). In total, 200 women completed the survey, and 77 (38.5%) women required TVS-ET to have a 99.9% detection rate for endometrial cancer. Prior hysteroscopy experience was the only factor that influenced the women's decisions: a significantly higher detection rate was required by this patient group than by patients without previous hysteroscopy experience (P=0.047). CONCLUSION: A substantial proportion of women would accept TVS-ET alone for the investigation of postmenopausal bleeding. In the era of patientcentred care, clinicians should incorporate patient preferences and enable women to make informed choices concerning the management of postmenopausal bleeding.

Pictorial Blood Loss Assessment Chart for evaluating heavy menstrual bleeding in Asian women.

INTRODUCTION: Heavy menstrual bleeding is a common gynaecological problem, but some women may prefer not to articulate their menstrual problems. The objective of this study was to evaluate the usefulness and acceptability of the Pictorial Blood Loss Assessment Chart (PBAC) as a selfscreening tool in evaluation of menstrual blood loss among Asian women in Hong Kong. METHODS: This prospective cohort study recruited 206 women from the general gynaecology ward and out-patient clinic: 118 had self-perceived heavy menstrual bleeding and 88 had self-perceived normal menstrual flow. Participants were asked to fill in the PBAC for one menstrual cycle. RESULTS: Compared with women who had self-perceived normal menstrual flow, women with self-perceived heavy menstrual bleeding had significantly higher total PBAC scores and numbers of flooding episodes, larger clot sizes and numbers, more days of bleeding, and lower haemoglobin levels. Receiver-operating characteristic curve analysis demonstrated good pairwise associations of self-perceived symptoms with PBAC score and haemoglobin level. CONCLUSIONS: The PBAC can be used to differentiate self-perceived heavy and normal menstrual bleeding in Asian women in Hong Kong. It can also serve as an additional indicator of possible heavy menstrual bleeding to alert women of the need to seek early medical attention.

Effectiveness of a childbirth massage programme for labour pain relief in nulliparous pregnant women at term: a randomised controlled trial.

INTRODUCTION: The effect of massage for pain relief during labour has been controversial. This study investigated the efficacy of a programme combining intrapartum massage, controlled breathing, and visualisation for non-pharmacological pain relief during labour. METHODS: This randomised controlled trial was conducted in two public hospitals in Hong Kong. Participants were healthy low-risk nulliparous Chinese women ≥18 years old whose partners were available to learn massage technique. Recruitment was performed at 32 to 36 weeks of gestation; women were randomised to attend a 2-hour childbirth massage class at 36 weeks of gestation or to receive usual care. The primary outcome variable was the intrapartum use of epidural analgesia or intramuscular pethidine injection. RESULTS: In total, 233 and 246 women were randomised to the massage and control groups, respectively. The use of epidural analgesia or pethidine did not differ between the massage and control groups (12.0% vs 15.9%; P=0.226). Linear-by-linear analysis demonstrated a trend whereby fewer women used strong pharmacological pain relief in the massage group, and a greater proportion of women had analgesic-free labour (29.2% vs 21.5%; P=0.041). Cervical dilatation at the time of pethidine/epidural analgesia request was significantly greater in the massage group (3.8 ± 1.7 cm vs 2.3 ± 1.0 cm; P<0.001). CONCLUSION: The use of a massage programme appeared to modulate pain perception in labouring women, such that fewer women requested epidural analgesia and a shift was observed towards the use of weaker pain relief modalities; in particular, more women in the massage group were analgesic-free during labour.

External validation of a simple scoring system to predict pregnancy viability in women presenting to an early pregnancy assessment clinic.

INTRODUCTION: A scoring system combining clinical history and simple ultrasound parameters was developed to predict early pregnancy viability beyond the first trimester. The scoring system has not yet been externally validated. This study aimed to externally validate this scoring system to predict ongoing pregnancy viability beyond the first trimester. METHODS: This prospective observational cohort study enrolled women with singleton intrauterine pregnancies before 12 weeks of gestation. Women underwent examination and ultrasound scan to assess gestational sac size, yolk sac size, and fetal pulsation status. A pregnancy-specific viability score was derived in accordance with the Bottomley score. Pregnancy outcomes at 13 to 16 weeks were documented. Receiver-operating characteristic curve analysis was used to assess the discriminatory performance of the scoring system. RESULTS: In total, 1508 women were enrolled; 1271 were eligible for analysis. After adjustment for covariates, miscarriage (13%) was significantly associated with age ≥35 years (odds ratio [OR]=1.99, 95% confidence interval [CI]: 1.19-3.34), higher bleeding score (OR=2.34, 95% CI: 1.25-4.38), gestational age (OR=1.17, 95% CI: 1.13-1.22), absence of yolk sac (OR=4.73, 95% CI: 2.11-10.62), absence of fetal heart pulsation (OR=3.57, 95% CI: 1.87-6.84), mean yolk sac size (OR=1.25, 95% CI: 1.06-1.47), and fetal size (OR=0.82, 95% CI: 0.77-0.88). The area under the receiver operating characteristic curve was 0.91 (95% CI: 0.89-0.93). Viability score of ≥1 corresponded to a >90% probability of viable pregnancy. CONCLUSIONS: The scoring system was easy to use. A score of ≥1 could be used to counsel women who have a high likelihood of viable pregnancy beyond the first trimester.

Reappraisal of endometrial thickness for the detection of endometrial cancer in postmenopausal bleeding: a retrospective cohort study.

OBJECTIVE: To estimate the accuracy of transvaginal ultrasound (TVS) measurement of endometrial thickness (ET) in diagnosing endometrial cancer in postmenopausal women with vaginal bleeding (PMB). DESIGN: Retrospective cohort study. SETTING: One-stop PMB clinic in a Hong Kong teaching hospital. POPULATION: A cohort of 4383 women with PMB. METHODS: Transvaginal ultrasonic measurement of ET and endometrial biopsies were obtained in women presenting with PMB between 2002 and 2013. Endometrial histology was used as the reference standard to calculate accuracy estimates. MAIN OUTCOME MEASURES: Accuracy data for TVS ET presented as sensitivity, specificity, and area under the receiver operator characteristic (ROC) curve. RESULTS: Endometrial cancer was diagnosed in 3.8% of women. The median ET in those with endometrial cancer was significantly higher than those with benign conditions (15.7 versus 3.2 mm, P < 0.001). The area under the ROC curve was 0.92 (95% CI 0.89-0.94). The sensitivity for the detection of endometrial cancer at 3-, 4-, and 5-mm cut-offs were 97.0% (95% CI 94.5-99.6%), 94.1% (95% CI 90.5-97.6%), and 93.5% (95% CI 89.7-97.2%), respectively. The corresponding estimates of specificity at these thresholds were 45.3% (95% CI 43.8-46.8%), 66.8% (65.4-68.2%), and 74.0% (72.7-75.4%). CONCLUSIONS: Transvaginal ultrasound using a 3-mm cut-off has high sensitivity for detecting endometrial cancer and can identify women with PMB who are highly unlikely to have endometrial cancer, thereby avoiding more invasive endometrial biopsy.

Applicability of first-trimester combined screening for fetal trisomy 21 in a resource-limited setting in mainland China.

OBJECTIVE: To assess the feasibility and performance of the first-trimester combined screening test for trisomy 21 in a resource-limited setting in mainland China. DESIGN: Prospective observational cohort study. SETTING: First Affiliated Hospital of Kunming Medical University, China. POPULATION: Ten thousand four hundred and forty-two pregnant women requesting first-trimester screening. METHODS: The combined screening test was performed from May 2012 to December 2014. Women with a high-risk result (≥1:600) were offered further confirmatory tests after counselling. The threshold for high risk was determined by Monte Carlo simulation to achieve a 5% false-positive rate according to the local age distribution. Pregnancy outcome and screening results were recorded for all women and monthly audits were conducted. MAIN OUTCOME MEASURES: Sensitivity, screen positive rate, cost per case of Down syndrome detected. RESULTS: Six hundred and ten women (5.8% of the total screened) had a high-risk screening test, of whom 274 (44.9%) underwent a diagnostic test and 169 (27.7%) opted for a noninvasive prenatal screening test (NIPT); 160 (26.2%) declined further testing after counselling. The pregnancy outcome was available for 10 174 (97.4%) of the women. The observed incidence of Down syndrome was 0.13% (1/750). All 14 women with a trisomy 21 pregnancy had a high-risk screening test result. The cost per Down syndrome detected was RMB596 686 compared with RMB1.79 million if all had been screened by NIPT. CONCLUSIONS: The combined screening test appears to be a more cost-effective strategy in mainland China. Screening performance in China would be improved by adopting Chinese-specific models, external quality control and assurance, and establishing risk thresholds appropriate for the age distribution of the population. TWEETABLE ABSTRACT: Combined first-trimester Downs screening in China was improved by adopting Chinese-specific models and external QC.

Maternal ABO and rhesus blood group phenotypes and hepatitis B surface antigen carriage.

In view of a persistently high prevalence of hepatitis B surface antigen (HBsAg) carriage in our obstetric population, we examined the association between HBsAg carriage with maternal ABO and rhesus (Rh) blood group phenotypes determined at routine antenatal screening. In a retrospective study, the antenatal screening results of women booked for confinement between 1998 and 2011 in our hospital were examined for the relationship between HBsAg carriage with the ABO and rhesus blood groups, taking into account also the effects of advanced maternal age (≥ 35 years) and parity status (nulliparous or multiparous), and year of birth before or following the availability of the hepatitis B vaccine (1984). HBsAg carriage was found in 9.9%, 9.6%, 9.1% and 10.2% (P = 0.037) for group-A (n = 20 581 or 26.1%), -B (n = 20 744 or 26.4%), -AB (n = 5138 or 6.5%) and -O (n = 32 242 or 41.0%) among the 78705 women in the study cohort. Rhesus negativity was found in 0.6%, and HBsAg carriage was 12.3% and 9.8%, respectively, for the Rh-negative and Rh-positive women (P = 0.071). Carriage rate between group-O and non-O was influenced by nulliparity, age ≥ 35 years and Rh-positive status. Regression analysis indicated that group-B (P = 0.044, aOR = 1.062, 95% CI 1.002-1.127) and group-AB (P = 0.016, aOR = 1.134, 95% CI 1.024-1.256) were associated with HBsAg carriage. Blood groups-B and -AB are associated with increased hepatitis B virus (HBV) infection in our population, and further studies are warranted to elucidate the implications of this on the sequelae of HBV infection.

Diabetes and pregnancy: perspectives from Asia.

There has been a marked increase in the prevalence of diabetes in Asia over recent years. Diabetes complicating pregnancy, in particular gestational diabetes, has also increased markedly in the region. Multi-ethnic studies have highlighted the increased risk of gestational diabetes mellitus among the different Asian populations. Prevalence of gestational diabetes in Asian countries varies substantially according to the screening strategy and diagnostic criteria applied, and ranges from 1% to 20%, with evidence of an increasing trend over recent years. The International Association for Diabetes in Pregnancy Study group criteria have been adopted by some Asian countries, although they present significant challenges in implementation, especially in low-resource settings. Studies on offspring of mothers with gestational diabetes have reported adverse cardiometabolic profiles and increased risk of diabetes and obesity. Gestational diabetes is likely to be a significant factor contributing to the epidemic of diabetes and other non-communicable diseases in the Asian region. In recognition of this, several large-scale prevention and intervention programmes are currently being implemented in different Asian countries in order to improve glucose control during pregnancy, as well as overall maternal health. Lessons emerging from gestational diabetes studies in Asia may help inform and provide insights on the overall burden and treatment strategies to target gestational diabetes, with the ultimate aim to reduce its adverse short- and long-term consequences.

Diagnostic accuracy of the BACs-on-Beads™ assay versus karyotyping for prenatal detection of chromosomal abnormalities: a retrospective consecutive case series.

OBJECTIVE: To evaluate the diagnostic performance of the BACs-on-Beads(™) (BoBs(™)) assay for prenatal detection of chromosomal abnormalities. DESIGN: Retrospective study. SETTING: Tertiary prenatal diagnosis centre. POPULATION: Women referred for prenatal diagnosis. METHODS: We retrieved 2153 archived DNA samples collected between January 2010 and August 2011 for the BoBs(™) assay. These samples had previously been tested by quantitative fluorescence polymerase chain reaction (QF-PCR) and karyotyping. In the BoBs(™) assay a sample was defined as normal disomic when the ratio of the fluorescence intensities in a chromosome locus lay within the threshold (mean ratio ± 2SD), and as deleted or duplicated when the ratio was below the lower threshold (0.6-0.8) or above the upper threshold (1.3-1.4), respectively. The BoBs(™) results were further validated by microarray and compared in a blinded manner with the original QF-PCR and karyotyping results. MAIN OUTCOME MEASURES: Concordance of any numerical, structural, and submicroscopic chromosomal abnormalities between the methods. RESULTS: BACs-on-Beads(™) was similar to karyotyping and QF-PCR in detecting trisomy 13, trisomy 18, trisomy 21, and sex chromosomal aneuploidies, and superior to QF-PCR in detecting major structural abnormalities (53.3 versus 13.3%) and mosaicism (28.6 versus 0%) involving chromosomal abnormalities other than the common aneuploidies. BoBs(™) detected six microdeletion syndromes missed by karyotyping and QF-PCR; however, BoBs(™) missed two cases of triploidy identified by QF-PCR. Therefore, the sensitivity of BoBs(™) is 96.7% (95% CI 92.6-98.7%), and its specificity is 100% (95% CI 99.8-100%). CONCLUSIONS: BACs-on-Beads(™) can replace QF-PCR for triaging in prenatal diagnosis, and gives a better diagnostic yield than current rapid aneuploidy tests.

Maternal hepatitis B surface antigen status and incidence of pre-eclampsia.

The relationship between chronic hepatitis B virus (HBV) infection with atherosclerosis and cardiovascular disorders remains unclear, and the impact of maternal HBV infection on the development of pregnancy-induced hypertension (PIH) and pre-eclampsia (PE) is also controversial. This retrospective cohort study was conducted to examine the relationship between maternal hepatitis B surface antigen (HBsAg) status with PIH and PE in singleton pregnancies that delivered at 24 weeks of gestation and beyond. Among the 86 537 cases in the cohort, 10% were HBsAg positive, and overall 2.0% had PIH, of whom 56.3% developed PE. HBsAg-positive women had higher weight and body mass index (BMI), but lower incidences of advanced age, nulliparity, PIH (1.6% vs 2.0%, P = 0.007) and PE (0.8% vs 1.1%, P = 0.005). On multiple logistic regression analysis adjusting for the effects of nulliparity, advanced age, high BMI, and underlying renal, cardiac and autoimmune diseases, HBsAg carriage was associated with significantly reduced incidence of PIH (aOR 0.79, 95% CI 0.66-0.95) and PE (aOR 0.71, 95% CI 0.56-0.91). Our results indicate that maternal HBsAg carriage is independently associated with reduced PE. As chronic HBV infection alters the immune response of the individual, our observation could be related to enhanced maternal immunotolerance of the foetus and hence a reduction in the incidence of PE. The implications of our findings on the long-term health outcome of the infected women, from cardiovascular morbidity to malignancies, warrant further studies.

Relationship between age and prevalence of hepatitis B infection in first-year university students in Hong Kong.

PURPOSE: To determine the effect of age on the prevalence of hepatitis B virus (HBV) infection during a routine screening programme of first-year students enrolled in Health Sciences Studies at the Chinese University of Hong Kong from 2001 to 2009. METHODS: In a retrospective cohort study, data on the hepatitis B surface antigen (HBsAg) status was retrieved from the University Health Service and analysed according to the age of the student at testing and year of birth. RESULTS: Of the 2,688 students enrolled in the study group, 79 (2.9 %) tested positive for HBsAg. The prevalence increased significantly from 0.9, 2.3, 4.3 to 5.5 % for those tested at age ≤ 18, 19, 20 and ≥ 21 years, respectively (p < 0.001). On logistic regression analysis, taking age ≤ 18 years and year of birth before 1983 (before the availability of HBV vaccination) as the reference group, HBV infection increased progressively with age, with an adjusted odds ratio of 3.36 [95 % confidence interval (CI) 1.01-11.23], 6.04 (95 % CI 1.74-20.98) and 11.61 (95 % CI 3.20-42.13) for age 19, 20 and ≥ 21 years, respectively. There was no significant change in the odds ratio after adjustment for the year of birth before and after introduction of the vaccination programme. CONCLUSION: Among the university students enrolled in our study, the overall prevalence of HBV infection before and after the introduction of HBV vaccination was lower than the 10 % found in the general population. There was, however, a significant progressive increase with age at testing from ≤ 18 to ≥ 21 years, suggesting a previously overlooked contribution of horizontal transmission to the high prevalence of HBV infection found in our adult population.

Impact of neonatal hepatitis B vaccination programme on age-specific prevalence of hepatitis B infection in teenage mothers in Hong Kong.

We examined the impact of the neonatal hepatitis B immunization programme, first provided to all neonates born to mothers screened positive for hepatitis B surface antigen (HBsAg) in late 1983, on the age-specific prevalence of HBsAg carriage in teenage mothers managed in 1998­2008. HBsAg carriage was found in 2.5%, 2.7%, 8.8% and 8.0% of mothers aged ≤ 16, 17, 18, and 19 years, respectively (P=0.004), which was also correlated with advancing age (P=0.011). While neither difference nor correlation with age was found in mothers born before 1984, the prevalence of 1.2%, 1.5%, 7.1% and 8.3%, respectively, was significantly different among (P=0.008) and correlated with (P=0.002) age in mothers born 1984 onwards. Regression analysis indicated there was a significantly higher incidence of HBsAg carriage from age 17 onwards (adjusted odds ratio 2.55, 95% confidence interval 1.07­6.10, P=0.035), suggesting that the protective effect of the vaccine declined in late adolescence.

Maternal HBsAg status and infant size--a Faustian bargain?

Information on the impact of maternal hepatitis B virus (HBV) infection on pregnancy outcome is conflicting. Some studies reported an association with increased infant birthweight, which could be interpreted as advantageous to pregnancy. A retrospective study was performed to compare birthweight outcome between 6261 and 55,817 singleton pregnancies in mothers screened positive and negative for hepatitis B surface antigen (HBsAg), respectively. The HBsAg positive women were younger, had higher body mass index (BMI) and incidence of overweight, but less gestational weight gain, and were associated with increased macrosomia (birthweight ≥4000 g) in mothers <35 years (odds ratio, OR, 1.28), BMI ≥25 kg/m(2) (OR 1.24), without gestational diabetes mellitus (GDM, OR 1.19), and in male infants (OR 1.18). It was also associated with increased large-for-gestational age (LGA, birthweight >90th percentile) infants in nulliparas (OR 1.13), age <35 years (OR 1.12), BMI ≥25 kg/m(2) (OR 1.19), with (OR 1.36) and without (OR 1.09) GDM, and in male infants (OR 1.13). When the effects of high BMI, advanced age, GDM, and male infants were controlled for, positive HBsAg was significantly associated with macrosomic (adjusted odds ratio, aOR, 1.15) and LGA (aOR 1.11) infants. In view of the latest findings on the association between high infant birthweight with increased risk of obesity, diabetes mellitus, and various forms of malignancies from childhood to adulthood, further studies are warranted to determine if maternal hepatitis B infection would impact adversely on the long-term health of the offspring through its effect on increasing birthweight.

Correlation between maternal hepatitis B surface antigen carrier status with social, medical and family factors in an endemic area: have we overlooked something?

PURPOSE: Hepatitis B virus (HBV) infection is endemic in many countries, but the risk factors for HBV carriage in the obstetric population are unclear. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Head-to-body delivery interval and risk of fetal acidosis and hypoxic ischaemic encephalopathy in shoulder dystocia: a retrospective review.

OBJECTIVE: To examine the association between head-to-body delivery interval (HBDI) and cord arterial pH and base excess (BE), and the risk of development of hypoxic ischaemic encephalopathy (HIE). DESIGN: Retrospective review. SETTING: A university hospital. POPULATION: Pregnancies complicated with shoulder dystocia during the period 1995-2009. METHODS: Cases were identified from a search of the hospital electronic delivery records. Cord arterial pH and BE, and the incidence of HIE and perinatal death, were retrieved from medical records and correlated with HBDI, birth weight, mode of delivery and presence of nonreassuring fetal heart rate pattern and maternal diabetes using univariate analysis, followed by multivariate analysis. MAIN OUTCOME MEASURES: Any association between cord pH and HBDI. RESULTS: Of the 200 cases identified, the mean (standard deviation) HBDI was 2.5 minutes (1.5 minutes). Both HBDI and the presence of nonreassuring fetal heart rate pattern were independent factors for pH, and HBDI was the only significant factor for BE. Arterial pH dropped at a rate of 0.011 per minute [95% confidence interval (95% CI), 0.017-0.004; P = 0.002] with HBDI. The mode of delivery, birth weight and maternal diabetes did not affect blood gas levels. The respective risks of severe acidosis (pH < 7) and HIE with HBDI of <5 minutes were 0.5% and 0.5% versus 5.9% and 23.5% with HBDI ≥ 5 minutes. CONCLUSIONS: Cord arterial pH drops with HBDI during shoulder dystocia, but the risk of acidosis or HIE is very low with HBDI < 5 minutes.

Comparison of perinatal outcomes of shoulder dystocia alleviated by different type and sequence of manoeuvres: a retrospective review.

OBJECTIVE: To evaluate the different types and sequences of manoeuvres to overcome shoulder dystocia and the rates of associated fetal injury. DESIGN: Retrospective review. SETTING: A university hospital. POPULATION: Pregnancies complicated with shoulder dystocia from 1995 to 2009. METHODS: Cases were identified from the hospital electronic delivery records. MAIN OUTCOME MEASURES: The success rate between McRoberts' manoeuvre, rotational methods and posterior arm delivery, and the incidences of brachial plexus injury (BPI), clavicular fracture (CF) and humeral fracture (HF) according to the types and sequences of manoeuvres applied to overcome shoulder dystocia. RESULTS: Among 205 cases identified, McRoberts' manoeuvre was successful initially in 25% of cases, of which 7.8% suffered from BPI and 3.9% suffered from CF, but none had HF. In the failed cases, subsequent rotational methods and posterior arm delivery were similarly successful (72.0 versus 63.6%), whereas the former was associated with less BPI (4.4 versus 21.4%) and HF (1.1 versus 7.1%) despite similar risk of CF (5.6 versus 7.1%). The rotational methods were not associated with a higher fetal injury risk compared with McRoberts' manoeuvre. The remaining cases were managed by applying the third yet untried manoeuvre, and posterior arm delivery and rotational methods had similar success (77.1 versus 62.5%). The cumulative success rates after the second and the third manoeuvres were 79.0 and 94.6%, respectively. CONCLUSION: Following the failure of McRoberts' manoeuvre, subsequent application of rotational methods and posterior arm delivery have similarly high success rates but the former may be associated with less fetal injury.

Chronic hepatitis B virus infection and rubella susceptibility in pregnant women.

Increased rubella susceptibility has been shown in subjects from the Asian-Pacific region where chronic hepatitis B virus (HBV) infection is endemic. This study was performed to explore the relationship between chronic HBV infection and rubella susceptibility in the obstetric population. We conducted a retrospective cohort study on 50556 pregnant women delivered in a university obstetric unit from January 1998 to June 2008. The incidence of rubella susceptibility according to maternal HBV carrier status was examined. HBV infection and rubella susceptibility were found in 5105 (10.1%) and 6102 (12.1%) women, respectively. Rubella susceptibility was more common in women with HBV (13.1%vs 12.0%, P = 0.017), even after adjusting for other confounding factors (odds ratio 1.11, 95% confidence interval 1.01-1.21). Advancing age was associated with progressively decreasing odds of rubella susceptibility, from 0.48 at age 20-24 years to 0.34 at age ≥ 40 years in women without HBV infection, but had no effect in women with hepatitis B. In conclusion, our study is the first to demonstrate an association between chronic HBV infection with rubella susceptibility. Further studies are warranted to confirm whether chronic HBV infection, especially that acquired by vertical transmission, may impair the immune response to rubella vaccine or natural infection throughout the reproductive age.

Implications of the relationship between maternal age and parity with hepatitis B carrier status in a high endemicity area.

This study aimed to examine the prevalence of maternal hepatitis B virus (HBV) infection in the past 10 years and the age- and parity-specific incidences for evidence of control of HBV infection in the female reproductive population. We conducted a retrospective cohort study on 58 736 consecutive pregnant women delivered from July 1998 to June 2008. Maternal HBV status and demographic data were retrieved from a computerized database for analysis by year, age, year of birth and parity. A total of 5788 (10.1%) women had HBV infection, and the annual prevalence was around 10% throughout. When categorized by maternal age into six 5-year cohorts, the incidence increased from 6.8% in the <20 years cohort to 10.8% in the 20-24 and 25-29 year cohorts, then declined to 9.3% in the > or =40 years cohort (P < 0.001). When categorized by year of birth into 5-year cohorts, the incidence varied from 9.2% for the 1965-1969 cohort to 11.3% in the 1980-1984 cohort, which then declined to 7.3% in the > or =1985 cohort (P < 0.001). Multiparas had higher incidence when compared with nulliparas overall (10.5% vs 9.6%, P = 0.001), and significantly higher incidences for the 25-29 year (P = 0.009), 30-34 year (P < 0.001) and 35-39 year (P = 0.032) cohorts when analysed by age. In conclusion, the prevalence of maternal HBV infection remained constant at 10% for the past decade. The changes in relation to age and parity suggested that horizontal transmission, probably by sexual contact, had played an important role in maintaining the same prevalence as reported from Hong Kong 20 years ago.