Non-visualisation of fetal gallbladder in a Chinese cohort.

INTRODUCTION: Non-visualisation of fetal gallbladder (NVFGB) is associated with chromosomal abnormalities, biliary atresia, cystic fibrosis, and gallbladder agenesis in Caucasian fetuses. We investigated the outcomes of fetuses with NVFGB in a Chinese cohort. METHODS: This retrospective analysis included cases of NVFGB among Chinese pregnant women at five public fetal medicine clinics in Hong Kong from 2012 to 2019. We compared the incidences of subsequent gallbladder visualisation, chromosomal abnormalities, biliary atresia, cystic fibrosis, and gallbladder agenesis between cases of isolated NVFGB and cases of non-isolated NVFGB. RESULTS: Among 19 cases of NVFGB detected at a median gestational age of 21.3 weeks (interquartile range, 20.0-22.3 weeks), 10 (52.6%) were isolated and nine (47.4%) were non-isolated. Eleven (58.0%) cases had transient non-visualisation, four (21.0%) had gallbladder agenesis, three (15.8%) had chromosomal abnormalities (trisomy 18, trisomy 21, and 22q11.2 microduplication), one (5.2%) had biliary atresia, and none had cystic fibrosis. The incidence of serious conditions was significantly higher in the non-isolated group than in the isolated group (44.4% vs 0%; P=0.029); all three cases with chromosomal abnormalities and the only case of biliary atresia were in the non-isolated group, while all four cases with gallbladder agenesis were in the isolated group. The incidences of transient non-visualisation were similar (55.6% vs 60.0%; P=1.000). CONCLUSION: Isolated NVFGB is often transient or related to gallbladder agenesis. While investigations for chromosomal abnormalities and biliary atresia are reasonable in cases of NVFGB, testing for cystic fibrosis may be unnecessary in Chinese fetuses unless the NVFGB is associated with consistent ultrasound features, significant family history, or consanguinity.

Relationship between viral load, infection-to-delivery interval and mother-to-child transfer of anti-SARS-CoV-2 antibodies.

OBJECTIVE: To investigate the association of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load and infection-to-delivery interval with maternal and cord serum concentrations of anti-SARS-CoV-2 immunoglobulin G (IgG) antibodies and transplacental transfer ratio in pregnant women with active or recovered SARS-CoV-2 infection. METHODS: This was a prospective case series of consecutive pregnant women with laboratory-confirmed SARS-CoV-2 infection between 27 March 2020 and 24 January 2021. We collected information regarding deep throat saliva or nasopharyngeal swab (NPS) reverse transcription polymerase chain reaction (RT-PCR) test results, serial cycle threshold (Ct) values at and after diagnosis, demographic, clinical and outcome data, and neonatal NPS RT-PCR results. Qualitative and quantitative analysis of IgG and immunoglobulin M (IgM) antibodies against SARS-CoV-2 was performed in maternal and cord blood serum samples obtained at delivery. Correlation of maternal Ct values, infection-to-delivery interval, infection duration and viral load area under the curve (AUC) with gestational age (GA) at diagnosis, maternal and cord serum IgG concentrations and transplacental transfer ratio of IgG were evaluated using Pearson's correlation. RESULTS: Twenty pregnant women who consented to participate and who had delivered their babies by 31 January 2021 were included in the study, comprising 14 who had recovered from coronavirus disease 2019 (COVID-19) and six with active infection at delivery. The median GA at clinical manifestation was 32.7 (range, 11.9-39.4) weeks. The median infection-to-delivery interval and infection duration were 41.5 (range, 2-187) days and 10.0 (range, 1-48) days, respectively. The median GA at delivery was 39.1 (range, 32.4-40.7) weeks and the median seroconversion interval was 14 (range, 1-19) days. Of 13 neonates born to seropositive mothers with recovered infection at delivery, 12 tested positive for anti-SARS-CoV-2 IgG. All neonatal NPS samples were negative for SARS-CoV-2 and all cord sera tested negative for IgM. The median transplacental transfer ratio of IgG was 1.3 (interquartile range, 0.9-1.6). There was a negative correlation between infection-to-delivery interval and anti-SARS-CoV-2 IgG concentrations in maternal (r = -0.6693, P = 0.0087) and cord (r = -0.6554, P = 0.0068) serum and a positive correlation between IgG concentration in maternal serum and viral load AUC (r = 0.5109, P = 0.0310). A negative correlation was observed between transfer ratio and viral load AUC (r = -0.4757, P = 0.0409). CONCLUSIONS: In pregnant women who have recovered from COVID-19, anti-SARS-CoV-2 IgG concentrations at delivery increased with increasing viral load during infection and decreased with increasing infection-to-delivery interval. The median transplacental transfer ratio of IgG was 1.3 and it decreased with increasing viral load during infection. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Pattern and predictors of medical care received by hepatitis B carriers during pregnancy and after delivery.

OBJECTIVE: The objective of the study is to evaluate the pattern and predictors of medical care received by hepatitis B virus (HBV) carriers during pregnancy and after delivery in Hong Kong. STUDY DESIGN: The study is a retrospective analysis. METHODS: Pregnant HBV carriers and their infants were followed up for 9-12 months after delivery. Face-to-face interviews were conducted to investigate what medical care they received for HBV before, during and after pregnancy. RESULTS: Data were available for 412 HBV carriers. A total of 375 (91.0%) women were known HBV carriers before pregnancy. Routine antenatal screening picked out the remaining 37 (9.0%) HBV carriers; these women were younger, more likely to be smokers and had a lower level of education (P < 0.05) than known HBV carriers. In total, 356 of 412 (86.4%) HBV carriers did not receive any medical care for HBV during pregnancy. Known HBV carrier status, history of medical check-up and the use of antiviral treatment before pregnancy were significant predictors for HBV medical care during pregnancy (P < 0.05). The results show that 217 of 412 (52.6%) HBV carriers did not receive medical care for HBV after delivery. HBV medical care before pregnancy, use of antiviral treatment before pregnancy and a higher level of education were significant predictors for postpartum HBV medical care (P < 0.05). Multivariate analysis showed that HBV medical care before pregnancy (odds ratio [OR], 7.73; 95% confidence interval [CI], 3.21-18.65; P < 0.001) and the use of antiviral treatment (OR, 5.02; 95% CI, 1.41-17.81; P = 0.013) were associated with medical care during pregnancy. Medical care before pregnancy was also associated with postpartum HBV medical care (OR, 5.05; 95% CI, 3.29-7.51; P < 0.001). CONCLUSIONS: A significant proportion of HBV carriers did not receive HBV-related medical check-ups during and after pregnancy in Hong Kong despite the majority being aware of their carrier status. Medical care before pregnancy predicted antenatal and postpartum HBV medical care.

The first pilot study of expanded newborn screening for inborn errors of metabolism and survey of related knowledge and opinions of health care professionals in Hong Kong.

INTRODUCTION: Newborn screening is important for early diagnosis and effective treatment of inborn errors of metabolism (IEM). In response to a 2008 coroners' report of a 14-year-old boy who died of an undiagnosed IEM, the OPathPaed service model was proposed. In the present study, we investigated the feasibility of the OPathPaed model for delivering expanded newborn screening in Hong Kong. In addition, health care professionals were surveyed on their knowledge and opinions of newborn screening for IEM. METHODS: The present prospective study involving three regional hospitals was conducted in phases, from 1 October 2012 to 31 August 2014. The 10 steps of the OPathPaed model were evaluated: parental education, consent, sampling, sample dispatch, dried blood spot preparation and testing, reporting, recall and counselling, confirmation test, treatment and monitoring, and cost-benefit analysis. A fully automated online extraction system for dried blood spot analysis was also evaluated. A questionnaire was distributed to 430 health care professionals by convenience sampling. RESULTS: In total, 2440 neonates were recruited for newborn screening; no true-positive cases were found. Completed questionnaires were received from 210 respondents. Health care professionals supported implementation of an expanded newborn screening for IEM. In addition, there is a substantial need of more education for health care professionals. The majority of respondents supported implementing the expanded newborn screening for IEM immediately or within 3 years. CONCLUSION: The feasibility of OPathPaed model has been confirmed. It is significant and timely that when this pilot study was completed, a government-led initiative to study the feasibility of newborn screening for IEM in the public health care system on a larger scale was announced in the Hong Kong Special Administrative Region Chief Executive Policy Address of 2015.

Prevention of early onset group B streptococcal disease by universal antenatal culture-based screening in all public hospitals in Hong Kong.

OBJECTIVES: To determine the prevalence of maternal colonization with group B streptococcus (GBS), and early onset GBS disease (EOGBSD) after implementation of universal screening. METHODS: This was a three-year retrospective cohort study on universal antenatal rectovaginal culture-based screening and intrapartum antimicrobial prophylaxis (IAP) to colonized women in the public sector in Hong Kong. Routinely collected data including maternal colonization and EOGBSD were retrieved. RESULTS: Of 113,989 GBS screening performed, 21.8% were positive. The colonization rate was higher in the public hospitals (higher risk) than in the Maternal and Child Health Centers (lower risk) (23.7% vs 18.1%, p < .001), while their false negative rates were not greater than expected. Majority of eligible women opted for screening, and colonized women received IAP. There were 29 cases of EOGBSD with clinical signs and a positive blood or cerebrospinal fluid culture. Compared to clinical risk-based screening, EOGBSD incidence decreased after universal screening (1 vs 0.24 per 1000 births, p < .001). Although EOGBSD occurred at a higher rate in preterm than term infants, 86.7% occurred in the latter, and were associated with a false negative screening result (41.3%), lack of screening (20.7%) or unavailability of a colonization result at labour (13.8%). CONCLUSIONS: Maternal GBS colonization rate was higher than previously reported, and varied with different risk populations. EOGBSD reduced after universal screening.

Cloning and expression analysis of a mouse gene related to Drosophila odd-skipped.

The Drosophila pair-rule gene odd-skipped (odd) and two related genes, sister of odd (sob) and bowel (bowl), encode zinc finger containing proteins, two of which play important roles in embryonic development probably functioning as transcription factors. Here we report the cloning and expression analysis of a mouse gene related to odd, odd-skipped related 1 (Osr1). During early embryogenesis Osr1 is expressed in the intermediate mesoderm and in a dynamic pattern during limb and branchial arch development.