Publications by authors named "Tse-Ngong Leung"

Birth defects occur in up to 3% of all live births and are the leading cause of infant death. Here we present five individuals from four unrelated families, individuals who share similar phenotypes with disease-causal bi-allelic variants in NADSYN1, encoding NAD synthetase 1, the final enzyme of the nicotinamide adenine dinucleotide (NAD) de novo synthesis pathway. Defects range from the isolated absence of both kidneys to multiple malformations of the vertebrae, heart, limbs, and kidney, and no affected individual survived for more than three months postnatally.

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Plasma consists of DNA released from multiple tissues within the body. Using genome-wide bisulfite sequencing of plasma DNA and deconvolution of the sequencing data with reference to methylation profiles of different tissues, we developed a general approach for studying the major tissue contributors to the circulating DNA pool. We tested this method in pregnant women, patients with hepatocellular carcinoma, and subjects following bone marrow and liver transplantation.

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Objective: To examine the effectiveness of first trimester fetal Trisomy 21 (T21) screening using a combination of maternal age, nuchal translucency, maternal serum levels of free beta-hCG and PAPP-A in a predominantly Chinese population in Hong Kong.

Methods: Consecutive women who underwent the combined screening for T21 between 11 and 13 + 6 weeks of gestation between 2003 and 2007 were recruited. Risk of T21 was calculated using Fetal Medicine Foundation algorithm and karyotyping was advised when the risk was 1:300 or above.

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Background: A woman's childbirth experience has an influence on her future preferred mode of delivery. This study aimed to identify determinants for women who changed from preferring a planned vaginal birth to an elective cesarean section after their first childbirth.

Methods: This prospective longitudinal observational study involved two units that provide obstetric care in Hong Kong.

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Background: Parvovirus B19 infection during pregnancy is a known cause of nonimmune hydrops, while about one third of maternal infection is asymptomatic. Spontaneous abortion, hydrops fetalis, intrauterine growth retardation and meconium peritonitis are possible manifestations of fetal infection, but the infection can also be asymptomatic.

Case: Both fetuses in a dichorionic, diamniotic twin pregnancy were infected with parvovirus B19 infection, but only 1 fetus presented with hydrops fetalis.

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Background: Unidentified circulating factors derived from placenta are thought to be responsible for the exaggerated systemic inflammation leading to preeclampsia. Our aim was to identify the circulating factors present in preeclampsia and to investigate their relationship to the underlying systemic immune response responsible for the associated clinical manifestations.

Methods: We obtained blood samples from pregnant women with and without preeclampsia and performed comparative proteomic analyses to identify the abnormal circulating factors by 2-dimensional polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization time of flight for protein separation and identification.

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Background: Alpha-2 Macroglobulin (A2M) is a protease inhibitor that is present in both human and rat decidual tissue. In mice, decidual A2M prevents excessive trophoblastic invasion; however, its role in human decidual tissue is unknown. It is possible that A2M may also influence trophoblast invasion in human pregnancy, which would be reflected in increased A2M production in decidua basalis.

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Objective: To identify all pregnancies complicated by maternal dextrocardia and report the obstetric performance in these patients.

Study Design: A retrospective review of all deliveries between May 1984 and December 2004 at Prince of Wales Hospital, Chinese University of Hong Kong. Maternal demographic data as well as information on the antenatal course and delivery outcome were abstracted from the maternal records.

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Background: The objective of this study was to determine the institutional pregnancy loss rate following second-trimester genetic amniocentesis and to ascertain whether factors exist which would identify pregnancies at increased risk of having a procedure-related fetal loss.

Setting: University Teaching Hospital

Methods: Details of the procedure and pregnancy outcome of all patients who had amniocentesis planned or performed between 15-22 gestational weeks between January 1997 and June 2004 were extracted from our clinical audit database. The procedure-related fetal loss rate, defined as all unintended abortions, stillbirths and neonatal deaths without major fetal abnormalities or obvious obstetric causes, was determined and compared to a presumed background fetal loss rate of 0.

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Objective: This study was performed to investigate the preferences of Chinese pregnant women for Down syndrome-affected birth compared to invasive test-related miscarriage, using the standard gamble approach, and to investigate whether there is a difference in Utility Score between general obstetric patients and those who request prenatal screening.

Methods: An interviewer-administered survey was conducted on 67 women who presented to the General Obstetric Clinic for booking visits and 69 women who presented to the first-trimester Combined Screening Clinic for fetal Down syndrome in a University Obstetric Unit. Preferences for Down syndrome-affected birth compared to invasive test-related miscarriage were assessed using the standard gamble approach.

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Objective: To assess the effect of the prostaglandin E2 (PGE2) on fetal vascular blood flow during cervical priming.

Study Design: In a prospective, observational study, 32 pregnant women > or =37 weeks of gestation requiring PGE2 for induction of labor were recruited. The resistance indices (RIs) of umbilical artery, middle cerebral artery, renal artery and ductus venosum were measured before, 2 and 4 hours after insertion of a PGE2 vaginal pessary.

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Objective: To study the effect of ethnic Chinese on the medians of free beta-hCG and PAPP-A in the first trimester of pregnancy.

Methods: The data of 943 women undergoing first trimester combined screening for fetal Down syndrome were analysed to derive the Chinese-specific medians. The calculated risk of Down syndrome based on these Chinese-specific medians was compared with that based on the original algorithm of the Fetal Medicine Foundation (FMF).

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Objectives: To study the preference of pregnant women regarding the time taken to report the results of first-trimester combined screening for Down syndrome and their knowledge about it.

Methods: A questionnaire survey was conducted on a cohort of 325 pregnant participants who attended our first-trimester combined nuchal translucency and biochemical screening programme for fetal Down syndrome. This service was operated in a one-stop setting and the result of the screening test was available within 1 to 2 h after the collection of blood sample.

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In a prospective study of 247 pregnant Chinese women, the prevalence of sleep disturbances across pregnancy has been assessed using a set of validated questionnaires including the Sleep and Health Questionnaire (SHQ) and the Epworth Sleepiness Scale (ESS). The frequency of self-reported snoring increased from 29.7% in the first trimester to 40.

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Background: Assessment of fetal cardiac function is difficult because of limited accessibility. Tissue Doppler imaging (TDI) is a promising technique in assessing diastolic function in adults. There has been sparseness concerning the use of TDI in assessing fetal cardiac function.

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Objective: To evaluate the pregnancy outcomes of two policies of timing of induction of labor for post-term pregnancies.

Study Design: It is a retrospective study in a University obstetric unit from 1997 to 2002. Five thousand eight hundred and ninety-two singleton, cephalic pregnancies with gestational age at delivery at or more than 41 completed weeks were studied.

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This study was performed to investigate the impact of hypertensive disorders of pregnancy at term on neonatal birth weight. All singleton live births delivered between 37 and 42 weeks of gestation complicated by hypertensive disorders over a 7-year period (n = 362) was compared to 34 783 uncomplicated singleton deliveries in the same period. The individualized gestation-related optimal weight (GROW) was calculated for each individual case adjusted for the effects of maternal booking weight, height, parity, gestation at delivery, and fetal sex.

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Purpose Of Review: To review the latest developments in screening and diagnosis of non-chromosomal genetic diseases.

Recent Findings: Major recent advances include the completion of the Human Genome Project, the use of microarray and related technologies for mass screening and diagnosis of thousands of genetic abnormalities, and non-invasive prenatal diagnosis using fetal DNA in maternal plasma.

Summary: The rapid development in molecular biological technologies makes it possible to screen and to diagnosis thousands of genetic conditions, mutations and also predispositions to chronic diseases or traits, either prenatally or after birth.

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Background: The aim of the study was to assess fetal vascular blood flow after amniotomy.

Methods: This was a prospective observational study. Thirty-five women with singleton pregnancy beyond 36 weeks of gestation, who underwent amniotomy, were recruited.

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Objective: The purpose of this study was to compare the umbilical arterial 8-iso-prostaglandin F2alpha, concentrations between pregnancies that were complicated by moderate or thick meconium-stained liquor and those with clear liquor.

Study Design: Umbilical cord arterial blood samples were collected from 247 singleton pregnancies with either moderate or thick meconium-stained liquor at any stage of labor or clear liquor at all stages of labor for the determination of the total 8-iso-prostaglandins F2alpha concentration.

Results: The median total 8-iso-prostaglandins F2alpha concentration of the meconium-stained liquor group was significantly higher than that of the control group (719.

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Objective: To evaluate and compare production of hepatocyte growth factor (HGF) from human first-trimester implantation-site decidua (decidua basalis) and nonimplantation site decidua (decidua parietalis), and hence to determine whether human trophoblast invasion in vivo is associated with increased decidual HGF production.

Design: Controlled prospective study.

Setting: University hospital-based study.

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The aim of this study was to determine whether corticotropin-releasing hormone (CRH) regulates human trophoblast cell growth. The results showed that exogenous CRH significantly stimulated human trophoblast proliferation in first-trimester primary cultures. In vivo, CRH was strongly immunolocalised to cytotrophoblastic cells in proliferative cell columns and in chorionic villi.

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Objective: To investigate the attitudes towards termination of pregnancy (TOP) among Hong Kong Chinese women attending the prenatal diagnosis counselling (PDC) clinic under three circumstances: (1) normal fetus, (2) fetal chromosomal anomalies, and (3) fetal abnormalities diagnosed after 24 weeks of gestation, and to determine the association between the attitudes and demographic factors.

Methods: One hundred and twenty-two women were interviewed using a structured questionnaire.

Results: Over 50% of our women viewed it as their right to choose an abortion in early pregnancy and only 28.

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