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.

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).

Menstrual, fertility and psychological impacts after uterine compression sutures for postpartum hemorrhage: a prospective cohort study.

BACKGROUND: Uterine compression suture is an important conservative surgical technique in managing atonic postpartum hemorrhage. In this study, we aim to evaluate the subsequent menstrual, fertility and psychological outcomes after uterine compression sutures. METHODS: This was a prospective cohort study between 2009 and 2022 conducted in a tertiary obstetric unit (6000 deliveries per year) in Hong Kong SAR. Women with primary postpartum hemorrhage successfully treated with uterine compression sutures were followed-up in postnatal clinic for two years after delivery. Data on menstrual pattern were collected during each visit. Psychological impact after uterine compression suture was assessed using a standardized questionnaire. Subsequent pregnancies were identified by territory-wide computer registry and telephone interviews. Women with postpartum hemorrhage treated with uterotonic agents only were chosen as controls. RESULTS: In our cohort (n = 80), 87.9% of women had return of menses within six months after delivery. Regular monthly cycle was observed in 95.6% of women. Majority of women reported similar menstrual flow (75%), menstrual days (85.3%) and no change in dysmenorrhea status (88.2%) as compared before. Among eight (11.8%) women who reported hypomenorrhea after uterine compression sutures, two cases of Asherman's syndrome were diagnosed. Among 23 subsequent pregnancies (16 livebirths), no significant differences in outcome were observed except more omental or bowel adhesions (37.5% vs. 8.8%, p = 0.007), recurrence of hemorrhage (68.8% vs. 7.5%, p < 0.001) and repeated compression sutures (12.5% vs. 0%, p = 0.024) were seen in women with previous compression sutures. Over half of the couple declined future fertility after uterine compression sutures with 38.2% of women recalled unpleasant memories and 22.1% reported life-long adverse impact especially tokophobia. CONCLUSION: Majority of women with history of uterine compression sutures had similar menstruation and pregnancy outcomes as compared to those who did not have sutures. However, they had higher intrapartum risk of visceral adhesions, recurrence of hemorrhage and repeated compression sutures next pregnancy. Furthermore, couple could be more susceptible to negative emotional impact.

Effectiveness of Interactive Digital Decision Aids in Prenatal Screening Decision-making: Systematic Review and Meta-analysis.

BACKGROUND: Increasing prenatal screening options and limited consultation time have made it difficult for pregnant women to participate in shared decision-making. Interactive digital decision aids (IDDAs) could integrate interactive technology into health care to a facilitate higher-quality decision-making process. OBJECTIVE: The objective of this study was to assess the effectiveness of IDDAs on pregnant women's decision-making regarding prenatal screening. METHODS: We searched Cochrane Central Register of Controlled Trials, MEDLINE, Embase, PsycINFO, World Health Organization International Clinical Trials Registry Platform, Google Scholar, and reference lists of included studies until August 2021. We included the randomized controlled trials (RCTs) that compared the use of IDDAs (fulfilling basic criteria of International Patient Decision Aid Standards Collaboration and these were interactive and digital) as an adjunct to standard care with standard care alone and involved pregnant women themselves in prenatal screening decision-making. Data on primary outcomes, that is, knowledge and decisional conflict, and secondary outcomes were extracted, and meta-analyses were conducted based on standardized mean differences (SMDs). Subgroup analysis based on knowledge was performed. The Cochrane risk-of-bias tool was used for risk-of-bias assessment. RESULTS: Eight RCTs were identified from 10,283 references, of which 7 were included in quantitative synthesis. Analyses showed that IDDAs increased knowledge (SMD 0.58, 95% CI 0.26-0.90) and decreased decisional conflict (SMD -0.15, 95% CI -0.25 to -0.05). Substantial heterogeneity in knowledge was identified, which could not be completely resolved through subgroup analysis. CONCLUSIONS: IDDAs can improve certain aspects of decision-making in prenatal screening among pregnant women, but the results require cautious interpretation.

Characteristics of Maternal Mortality Missed by Vital Statistics in Hong Kong, 2000-2019.

Importance: Reducing maternal mortality is a global objective. The maternal mortality ratio (MMR) is low in Hong Kong, China, but there has been no local confidential enquiry into maternal death, and underreporting is likely. Objective: To determine the causes and timing of maternal death in Hong Kong and identify deaths and their causes that were missed by the Hong Kong vital statistics database. Design, Setting, and Participants: This cross-sectional study was conducted among all 8 public maternity hospitals in Hong Kong. Maternal deaths were identified using prespecified search criteria, including a registered delivery episode between 2000 to 2019 and a registered death episode within 365 days after delivery. Cases as reported by the vital statistics were then compared with the deaths found in the hospital-based cohort. Data were analyzed from June to July 2022. Main Outcomes and Measures: The outcomes of interest were maternal mortality, defined as death during pregnancy or within 42 days after ending the pregnancy, and late maternal death, defined as death more than 42 days but less than 1 year after end of the pregnancy. Results: A total of 173 maternal deaths (median [IQR] age at childbirth, 33 [29-36] years) were found, including 74 maternal mortality events (45 direct deaths and 29 indirect deaths) and 99 late maternal deaths. Of 173 maternal deaths, 66 women (38.2%) of individuals had preexisting medical conditions. For maternal mortality, the MMR ranged from 1.63 to 16.78 deaths per 100 000 live births. Suicide was the leading cause of direct death (15 of 45 deaths [33.3%]). Stroke and cancer deaths were the most common causes of indirect death (8 of 29 deaths [27.6%] each). A total of 63 individuals (85.1%) died during the postpartum period. In the theme-based approach analysis, the leading causes of death were suicide (15 of 74 deaths [20.3%]) and hypertensive disorders (10 of 74 deaths [13.5%]). The vital statistics in Hong Kong missed 67 maternal mortality events (90.5%). All suicides and amniotic fluid embolisms, 90.0% of hypertensive disorders, 50.0% of obstetric hemorrhages, and 96.6% of indirect deaths were missed by the vital statistics. The late maternal death ratio ranged from 0 to 16.36 deaths per 100 000 live births. The leading causes of late maternal death were cancer (40 of 99 deaths [40.4%]) and suicide (22 of 99 deaths [22.2%]). Conclusions and Relevance: In this cross-sectional study of maternal mortality in Hong Kong, suicide and hypertensive disorder were the dominant causes of death. The current vital statistics methods were unable to capture most of the maternal mortality events found in this hospital-based cohort. Adding a pregnancy checkbox to death certificates and setting up a confidential enquiry into maternal death could be possible solutions to reveal the hidden deaths.

Application of Prenatal Whole Exome Sequencing for Structural Congenital Anomalies-Experience from a Local Prenatal Diagnostic Laboratory.

Fetal structural congenital abnormalities (SCAs) complicate 2-3% of all pregnancies. Whole-exome sequencing (WES) has been increasingly adopted prenatally when karyotyping and chromosomal microarray do not yield a diagnosis. This is a retrospective cohort study of 104 fetuses with SCAs identified on antenatal ultrasound in Hong Kong, where whole exome sequencing is performed. Molecular diagnosis was obtained in 25 of the 104 fetuses (24%). The highest diagnostic rate was found in fetuses with multiple SCAs (29.2%), particularly those with involvement of the cardiac and musculoskeletal systems. Variants of uncertain significance were detected in 8 out of the 104 fetuses (7.7%). Our study shows the utility of WES in the prenatal setting, and the extended use of the technology would be recommended in addition to conventional genetic workup.

Implementation of Public Funded Genome Sequencing in Evaluation of Fetal Structural Anomalies.

With the advancements in prenatal diagnostics, genome sequencing is now incorporated into clinical use to maximize the diagnostic yield following uninformative conventional tests (karyotype and chromosomal microarray analysis). Hong Kong started publicly funded prenatal genomic sequencing as a sequential test in the investigation of fetal structural anomalies in April 2021. The objective of the study was to evaluate the clinical performance and usefulness of this new service over one year. We established a web-based multidisciplinary team to facilitate case selection among the expert members. We retrospectively analyzed the fetal phenotypes, test results, turnaround time and clinical impact in the first 15 whole exome sequencing and 14 whole genome sequencing. Overall, the molecular diagnostic rate was 37.9% (11/29). De novo autosomal dominant disorders accounted for 72.7% (8/11), inherited autosomal recessive disorders for 18.2% (2/11), and inherited X-linked disorders for 9.1% (1/11). The median turnaround time for ongoing pregnancy was 19.5 days (range, 13-31 days). Our study showed an overall clinical impact of 55.2% (16/29), which influenced reproductive decision-making in four cases, guided perinatal management in two cases and helped future family planning in ten cases. In conclusion, our findings support the important role of genome sequencing services in the prenatal diagnosis of fetal structural anomalies in a population setting. It is important to adopt a multidisciplinary team approach to support the comprehensive genetic service.

Relationship between viral load and pregnancy outcomes among hepatitis B carriers.

OBJECTIVE: Pregnant hepatitis B carriers may have a higher risk of adverse pregnancy outcomes. Current evidences are conflicting regarding the relationship between hepatitis B virus (HBV) and various pregnancy complications, owing to the inclusion of women with different viral activity. This study is to evaluate the relationship between hepatitis B e antigen (HBeAg) status/HBV DNA level and pregnancy outcomes among pregnant hepatitis B carriers in Hong Kong. MATERIALS AND METHODS: This was a retrospective analysis of a prospective multicenter observational study carried out in Hong Kong between 2014 and 2016. Pregnant HBV carriers were recruited. HBeAg was tested. HBV DNA level was quantified at 28-30 weeks of gestation. The rates of gestational diabetes mellitus (GDM), gestational hypertension, pre-eclampsia, preterm prelabour rupture of membranes (PPROM), preterm birth, low birth weight (LBW), macrosomia and mode of delivery were recorded. RESULTS: 679 pregnancies were analyzed. 23.3% of women were seropositive for HBeAg. The mean viral load (SD) at 28-30 weeks of gestation was 3.6 (2.5) log10IU/ml. No statistically significant differences were found in the rates of GDM, gestational hypertension, pre-eclampsia, PPROM, preterm birth, LBW, macrosomia and mode of delivery among women with different viral load levels (≤2 log10IU/ml, 2.01-6 log10IU/ml and >6 log10IU/ml). Positive maternal HBeAg status was not associated with pregnancy complications compared to seronegative women. CONCLUSION: Seropositive HBeAg status or a higher level of HBV DNA during pregnancy did not pose a significant negative impact to the pregnancy outcomes.

Knowledge, perception and expectation of management of hepatitis B infection among pregnant hepatitis B carriers in Hong Kong.

Lack of awareness regarding the risk of hepatitis B virus (HBV) infection and the interventions available during pregnancy among the pregnant carriers may influence their willingness and adherence to the management. This study assessed the knowledge, perception and expectation of HBV infection among pregnant HBV carriers in Hong Kong. A prospective multicentre cross-sectional questionnaire study was carried out between August 2019 and April 2021. The general knowledge on HBV, perception and expectation, and interventions to reduce vertical transmission were questioned. Obtaining ≥70% correct answers was defined as having sufficient knowledge. 422 (82.7%) were known carriers. Only 18.4% of women had sufficient overall knowledge. The correct answer rates and percentage of sufficient knowledge were statistically lower for HBV knowledge specific to pregnancy compared with general knowledge (42.5% vs. 58.5%, p < 0.001; 8.8% vs. 30.2%, p < 0.001 respectively). Multiple logistic regression showed higher education and receiving HBV medical care within a year prior to pregnancy were associated with sufficient overall (OR 3.46; 95% CI 2.05-5.83 and OR 2.76; 95% CI 1.62-4.7, p < 0.001), and general knowledge (OR 2.86; 95% CI 1.81-4.51 and OR 2.14; 95% CI 1.33-3.44, p < 0.05). 298 (58.4%), 357 (70.0%) and 150 (29.4%) women believed they should receive care by obstetrician, hepatologist or general practitioner respectively. 46.9% did not want to initiate antiviral treatment due to the cost, perceived teratogenicity and maternal side effects. The knowledge of HBV among pregnant carriers in Hong Kong was poor despite the majority of them being aware of their carrier status prior to the pregnancy.

Prenatal phenotype of Kabuki syndrome: A case series and literature review.

OBJECTIVES: Kabuki syndrome (KS) is a genetic disorder characterized by intellectual disability, facial dysmorphism and congenital anomalies. We aim to investigate the prenatal features of fetuses with KS and to provide a comprehensive review of the literature on prenatal sonographic abnormalities associated with KS. METHODS: We retrospectively reviewed the prenatal ultrasound findings of all mothers of children with molecularly confirmed KS in Hong Kong, between 1991 and 2019. We also performed systematic review of the literature to identify studies on the prenatal findings in KS. RESULTS: We identified 11 cases with KS with detectable fetal ultrasound findings ranging from no detectable abnormalities to a variety of non-specific findings including increased nuchal translucency, pleural effusion, cardiac anomalies, renal anomalies, intrauterine growth restriction, polyhydramnios, oligohydramnios and single umbilical artery. In combining our cases with the 77 cases published, 42 (50.6%) of them had more than one abnormal antenatal ultrasound finding. The most frequent ultrasound features observed were cardiac anomalies (49.4%), followed by polyhydramnios (28.9%), genitourinary anomalies (26.5%), single umbilical artery (15.7%), intrauterine growth restriction (14.5%) and hydrops fetalis/pleural effusion/ascites (12.0%). CONCLUSIONS: These cases demonstrate the prenatal phenotypic heterogeneity associated with KS. Although the ultrasound abnormalities are non-specific, KS should be considered in the differential diagnosis when these fetal findings following normal microarray analysis/karyotyping.

Prevalence and risk factors for malignancy in hysteroscopy-resected endometrial polyps.

INTRODUCTION: To determine the prevalence of malignant lesions in endometrial polyps by hysteroscopic polypectomy, and risk factors for malignant transformation. The secondary aim was to evaluate background endometrium of atypical hyperplasia in endometrial polyps, and the risk of coexisting endometrial carcinoma after hysterectomy. METHODS: This retrospective study included women who underwent hysteroscopic polypectomy between January 2015 and December 2019. Demographic characteristics, hysteroscopic findings, and histopathology results of the polyp and the uterus, in the case of a hysterectomy, were collected. RESULTS: In all, 946 women were included in the study. Endometrial carcinoma in a polyp was found in 10 women (1.06%), and atypical hyperplasia was found in 11 women (1.16%). At the multivariate logistic regression model of risk factors, old age (P = 0.022) and obesity (P = 0.011) were significantly associated with (pre-)malignant polyp. Five of the ten women (50%) with atypical hyperplasia confined to a polyp had coexisting endometrial carcinoma in the hysterectomy specimen. CONCLUSION: Women with risk factors should be offered hysteroscopic polypectomy to allow a reliable histologic evaluation. Furthermore, hysterectomy is recommended in women with atypical hyperplasia in endometrial polyps even after complete resection.

Uterine compression sutures with additional hemostatic procedures for the management of postpartum hemorrhage.

AIM: The aim of the study was to evaluate the efficacies and possible short-term complications in women receiving uterine compression sutures only and those with additional hemostatic procedures for the management of postpartum hemorrhage. METHODS: It was a retrospective study carried out from year 2009 to 2019 at a tertiary obstetric hospital and included 79 women who underwent uterine compression sutures (B-Lynch sutures, Hayman's sutures and Cho's sutures) for primary postpartum hemorrhage. Thirty-six of these women had additional hemostatic procedures (uterine artery ligation or embolization) performed for bleeding control. RESULTS: Of the 43 women who were primarily treated with uterine compression sutures only, the success rate to preserve the uterus was 97.7% (42/43). In women with uterine compression sutures and additional hemostatic procedures performed, the success rate was 75% (27/36). Among these two groups of women without peripartum hysterectomy, there were no significant differences in the incidence of secondary postpartum hemorrhage (14.8% vs. 11.9%; P = 0.729), postoperative endometritis (14.8% vs. 14.3%; P > 0.99) and retained products of conception (3.7% vs. 9.5%; P = 0.641) during their 6-week postpartum checkup. Three women were diagnosed to have hematometra. No pyometra or uterine necrosis was noted. CONCLUSION: Uterine compression sutures with additional hemostatic procedures are effective to control postpartum hemorrhage and prevent hysterectomy. The short-term complication rate is low. Long-term monitoring is needed to identify rare but potentially dangerous complications.

Multicystic encephalomalacia and gastrointestinal injury following single fetal death in first trimester and subsequent fetofetal transfusion syndrome in a monochorionic triplet pregnancy: a case report.

BACKGROUND: Monochorionic multifetal pregnancies are at increased risk of adverse perinatal outcome because of placental vascular anastomoses. We present a case of multicystic encephalomalacia and gastrointestinal injury in two surviving fetuses following single fetal death in first trimester and subsequent fetofetal transfusion syndrome in a monochorionic triplet pregnancy. CASE PRESENTATION: A 31-year-old nulliparous woman had a spontaneous monochorionic triamniotic triplet pregnancy. Three live fetuses with single placenta were seen at 8-week ultrasound scan. One fetus demised at 11 weeks and 3 days of gestation. Dilated echogenic bowel and ascites were found in one surviving fetus at 23 weeks of gestation. At 28 weeks of gestation, the pregnancy was complicated by fetofetal transfusion syndrome in which discordant amniotic fluid volumes were found. Two days later, emergency Caesarean section was performed because of worsening of fetal Doppler and biophysical profile. One baby was found to have jejunal atresia requiring surgery at 4 days old. He had periventricular leukomalacia and intracranial haemorrhage, but subsequent normal neurological development. Another baby had gastric perforation requiring surgery at 2 days old. He was confirmed to have multicystic encephalomalacia by cranial ultrasound and magnetic resonance imaging. He suffered from developmental delay, epilepsy and cerebral palsy. CONCLUSION: This case alerts the obstetricians the possible hypoxic-ischemic injury to the survivors of monochorionic triplet pregnancy after the co-triplet death in the first trimester and fetofetal transfusion syndrome. Antenatal assessment and postnatal follow-up are important for these high-risk multiple pregnancies.

Decision outcomes in women offered noninvasive prenatal test (NIPT) for positive Down screening results.

In this first Asian study, the decision outcomes (decision conflict, decision regret, and anxiety) of 262 pregnant women offered noninvasive prenatal test (NIPT) for high-risk Down screening results were assessed. Decision conflict was experienced by 3.5% and level of decisional regret low (mean score 15.7, 95%CI 13.2-18.3). All 13 cases of decisional regret were NIPT acceptors. Elevated anxiety was experienced by 55.9% at the time of decision making about NIPT and persistent in 30.3%. Insufficient knowledge about NIPT was associated with elevated anxiety at decision making (p = .011) and with decisional regret (p = .016). Decisional regret was associated with prolonged anxiety (p = .010).

The effect of rupture of membranes and labour on the risk of hepatitis B vertical transmission: Prospective multicentre observational study.

OBJECTIVE: To evaluate the effect of rupture of membranes and labour on the risk of hepatitis B virus (HBV) vertical transmission. STUDY DESIGN: A prospective multicentre observational study was carried out in Hong Kong between 2014-2016. Pregnant HBV carriers were recruited. The duration of rupture of membranes, labour and mode of delivery were collected prospectively. HBV DNA was examined at 28-30 weeks of gestation. All newborns received standard HBV vaccination and immunoglobulin. Hepatitis B surface antigen of infants was tested at 9-12 months of age. RESULTS: 641 pregnancies were recruited and analyzed. No statistically significant difference was found in gravida, parity, gestational age at delivery, mode of delivery, duration of rupture of membranes, duration of labour, preterm delivery, preterm rupture of membranes or birth weight (p > 0.05). Subgroup analysis in viral load > 7log10IU/ml and 8log10IU/ml also did not find a significant association between duration of rupture of membranes and labour with immunoprophylaxis failure. CONCLUSIONS: Duration of rupture of membranes and labour would not affect the risk of HBV vertical transmission in infants following standard HBV vaccination and hepatitis B immunoglobulin administration.

Health professionals' involvement and information provision in genetic counseling following prenatal diagnosis of sex chromosome aneuploidy in Hong Kong.

This study supports training in genetic counseling for obstetricians and adoption of a multidisciplinary approach in the counseling process following prenatal diagnosis of sex chromosome aneuploidy.

Paternal uniparental disomy of chromosome 19 in a pair of monochorionic diamniotic twins with dysmorphic features and developmental delay.

BACKGROUND: We report here clinical, cytogenetic and molecular data for a pair of monochorionic diamniotic twins with paternal isodisomy for chromosome 19. Both twins presented with dysmorphic features and global developmental delay. This represents, to our knowledge, the first individual human case of paternal uniparental disomy for chromosome 19 (UPD19). METHODS: Whole-exome sequencing, together with conventional karyotype and SNP array analysis were performed along with genome-wide DNA methylation array for delineation of the underlying molecular defects. RESULTS: Conventional karyotyping on amniocytes and lymphocytes showed normal karyotypes for both twins. Whole-exome sequencing did not identify any pathogenic sequence variants but >5000 homozygous exonic variants on chromosome 19, suggestive of UPD19. SNP arrays on blood and buccal DNA both showed paternal isodisomy for chromosome 19. Losses of imprinting for known imprinted genes on chromosome 19 were identified, including ZNF331, PEG3, ZIM2 and MIMT1. In addition, imprinting defects were also identified in genes located on other chromosomes, including GPR1-AS, JAKMP1 and NHP2L1. CONCLUSION: Imprinting defects are the most likely cause for the dysmorphism and developmental delay in this first report of monozygotic twins with UPD19. However, epigenotype-phenotype correlation will require identification of additional individuals with UPD19 and further molecular analysis.