Ernest Ng

Ernest Ng
The University of Hong Kong | HKU · Department of Obstetrics and Gynaecology

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188
Publications
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Publications

Publications (188)
Article
In vitro fertilization is an effective treatment for various causes of infertility. However, management of women with poor ovarian response or premature ovarian insufficiency remains challenging because these women have under-developed small ovarian follicles that do not respond to hormone treatment. In vitro activation of small follicles has been...
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Background: Reducing maternal and perinatal mortality is a global objective. Hong Kong is a city with low maternal and perinatal mortality but little is known about the trend and causes of these deaths in this high-income city. We analyzed the maternal death, stillbirth and neonatal death since 1946 in Hong Kong. Methods: Data were extracted fro...
Article
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters cells via receptor angiotensin-converting enzyme 2 (ACE2) and co-receptor transmembrane serine protease 2 (TMPRSS2). However, patients with SARS-CoV-2 infection receiving ACE1 inhibitors had higher ACE2 expression and were prone to poorer prognostic outcomes. Until now, informa...
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Human endometrium is an incredibly dynamic tissue undergoing cyclic regeneration and shedding during a woman’s reproductive life. Endometrial mesenchymal stromal/stem-like cells (eMSC) contribute to this process. A hypoxic niche with low oxygen levels has been reported in multiple somatic stem cell types. However, the knowledge of hypoxia on eMSC r...
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Introduction In vitro fertilisation (IVF) is an effective infertility treatment but the live birth rate remains unsatisfactory. Ovarian stimulation by follicle-stimulating hormone (FSH) is routinely used in IVF and the resulting high serum estradiol levels may impair oocyte/embryo quality and endometrial receptivity. Letrozole, an aromatase inhibit...
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Background: The maternal immune system needs to tolerate the semi-allogeneic fetus in pregnancy. The adaptation occurs locally at the maternal-fetal interface as well as systemically through the maternal circulation. Failure to tolerate the paternal antigens may result in pregnancy complications, such as pregnancy loss and pre-eclampsia. However,...
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Endometrial mesenchymal stem-like cells (eMSC) reside in the basal layer of the endometrium and are responsible for cyclic regeneration during the reproductive lives of women. Myometrial cells act as a component of the niche and regulate the stem cell fate through the activation of WNT/β-catenin signaling via WNT5A. Since WNT5A-responsive mechanism...
Preprint
Background: Human endometrium undergoes cycles of regeneration in reproductive women and endometrial mesenchymal stromal/stem like cells (eMSC) contribute to this process. Notch signaling is essential for the homeostasis of somatic stem cells, however its role in eMSC remains largely unknown. Methods: RT-qPCR was used to compare the activity of Not...
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Objective: Vitamin D receptors are present in the female reproductive tract. Studies on the association between serum vitamin D level and pregnancy rate of in vitro fertilization (IVF) showed inconsistent results and focused on a single fresh or frozen embryo transfer cycle. The objective of our study was to evaluate if serum vitamin D level before...
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Objective With the surge of confirmed cases of coronavirus disease 2019 (COVID-19) and its associated morbidities and mortalities, continuous companion support during labour was halted in all public hospitals in Hong Kong to prevent the spread of the virus in hospitals. The purpose of this retrospective study was to evaluate the effect of not havin...
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STUDY QUESTION Does acupuncture improve insulin sensitivity more effectively than metformin or sham acupuncture in women with polycystic ovary syndrome (PCOS) and insulin resistance (IR)? SUMMARY ANSWER Among women with PCOS and IR, acupuncture was not more effective than metformin or sham acupuncture in improving insulin sensitivity. WHAT IS KNO...
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Background Acupuncture reduces pain levels in many painful conditions. This study compared pain levels during surgical termination of first trimester pregnancy by suction evacuation (SE) under local analgesia with and without the use of acupuncture. Methods In all, 60 nulliparous women undergoing SE before 10 weeks of gestation were randomly assig...
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Background In vitro fertilization (IVF) is a well-established method to treat various causes of infertility. Some previous retrospective studies suggested a lower ovarian response in Asian women compared to Caucasian women. However, the ovarian stimulation regimens were not standardized, potentially confounding the findings. The objective of this s...
Article
Background The mechanism of action of a contraceptive method is an importantg consideration in a woman’s choice of contraception. For the development of new methods of contraception it is important to understand the acceptability of different contraceptive mechanisms within a population. Methods We recruited women attending contraceptive, terminat...
Article
Sperm selection in the female reproductive tract (FRT) is sophisticated. Only about 1,000 sperm out of millions in an ejaculate reach the fallopian tube and thus have a chance of fertilizing an oocyte. In assisted reproduction techniques, sperm are usually selected using their density or motility, characteristics that do not reflect their fertiliza...
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Bisphenol A (BPA) is a well-known endocrine disruptor, widely used in various consumer products and ubiquitously found in air, water, food, dust, and sewage leachates. Recently, several countries have restricted the use of BPA and replaced them with bisphenol S (BPS) and bisphenol F (BPF), which have a similar chemical structure to BPA. Compared to...
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Increasing evidence shows that polycystic ovary syndrome (PCOS) patients are particularly vulnerable to anxiety/depression-like behaviors. This study sought to determine the prevalence of anxiety/depression-like behaviors among women with PCOS and to identify factors associated with these behaviors. This study was a secondary analysis of three stud...
Article
Non-obstructive azoospermia (NOA) and diminished ovarian reserve (DOR) are two disorders that can lead to infertility in male and female. Genetic factors have been identified to contribute to NOA and DOR. However, the same genetic factor that can cause both NOA and DOR remains largely unknown. To explore the candidate pathogenic gene that cause bot...
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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...
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Objective To assess the association of baseline anti‐Müllerian hormone (AMH) levels with ovulation, time to ovulation and fertility outcomes in women with polycystic ovary syndrome (PCOS) receiving clomiphene citrate (CC) and compare this with placebo. Design Secondary analysis of the PCOSAct trial (NCT01573858). Setting 27 trial centres in mainl...
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In this study, we used a network meta-analysis (NMA) to compare the effectiveness of medicines and supplements for idiopathic male infertility and to identify the best treatment. Medline, Excerpta Medica Database (EMBASE), Ovid, and China National Knowledge Infrastructure (CNKI), were searched for the period from January 1990 to June 2021 using the...
Article
Study question: Is there any difference in the ongoing pregnancy rate after immediate versus delayed frozen embryo transfer (FET) following a stimulated IVF cycle? Summary answer: Immediate FET following a stimulated IVF cycle produced significantly higher ongoing pregnancy and live birth rate than did delayed FET. What is known already: Embry...
Article
Objective To compare the effects of hyaluronic acid (HA)–enriched transfer medium versus standard medium on live birth rate after frozen embryo transfer (FET). Design Randomized, double-blind, controlled trial. Setting Two tertiary fertility centers. Patient(s) Infertile women aged <43 years at the time of in vitro fertilization undergoing FET....
Article
STUDY QUESTION Will use of oral progestogen in women with threatened miscarriage in the first trimester reduce the miscarriage rate when compared with placebo? SUMMARY ANSWER Use of oral progestogen in women with threatened miscarriage in the first trimester did not reduce miscarriage before 20 weeks when compared with placebo. WHAT IS KNOWN ALRE...
Article
The objective of this study was to evaluate the performance of ovarian response prediction index (ORPI) in predicting ovarian response and livebirth of women undergoing their first in-vitro fertilisation (IVF) cycle. This is a retrospective analysis of 285 women from 2013 to 2016. The outcome measures were area (AUC) under the receiver-operator cha...
Article
Objective This study investigated the role of women’s age, serum anti-Müllerian hormone (AMH) level and semen parameters in predicting fecundability. Methods This was a prospective cohort study on couples attending for preconceptional health check. Occurrence of conception at 1 year after ceasing contraception and time to pregnancy were noted by t...
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Serum anti-Mullerian hormone (AMH) levels are significantly higher in women with polycystic ovary syndrome (PCOS) than in normal ovulatory women. Different diagnostic cut-off values of AMH for discriminating women with PCOS from normal controls have been proposed. This is attributed partly to the different assay methods used with different calibrat...
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Objective: To establish the age-specific centiles of serum AMH levels in Chinese women, and to explore the use of multiples of median (MOM) AMH levels for the diagnosis of polycystic ovary syndrome (PCOS). Design: An observational study SETTING: University-affiliated hospitals and community clinics POPULATION: We included 3137 healthy women aged...
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Objective To study the use of human embryonic stem cell–derived trophoblastic spheroids (BAP-EB) as human blastocyst surrogates for studying early implantation and trophoblast development. Design Laboratory study. Setting University research laboratory. Patient(s) Infertile in vitro fertilization patients donating endometrial aspirates and human...
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Objective To test the hypothesis that acupuncture improves insulin sensitivity in women with polycystic ovary syndrome (PCOS) and insulin resistance (IR). Design Prospective pilot study. Setting Guangzhou, China, 2014–2016. Participants Eighty women with PCOS aged 18–40 years with body mass index (BMI) above 18.5 kg/m ² and with homeostatic mode...
Article
Research question Is fentanyl and midazolam non-inferior to pethidine and diazepam in pain relief during oocyte retrieval under conscious sedation? Design A randomized double-blinded non-inferiority trial of 170 infertile women undergoing oocyte retrieval under conscious sedation in an assisted reproduction centre. The women were randomized to rec...
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Background: Preterm birth accounts for 75% of perinatal deaths and more than 50% of long-term neurological disabilities. For a singleton pregnancy, progesterone treatment is effective in prevention of preterm birth in women with an asymptomatic short cervix or a history of preterm birth. However, a large proportion of preterm births still is not c...
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Long-read nanopore sequencing enables direct high-resolution breakpoint mapping on balanced carriers of reciprocal translocation. The mean sequencing depth on the translocated chromosomes to achieve accurate mapping of breakpoints ranged from 2.5-fold to 6.2-fold. To speed up determination of the breakpoints from long-read sequencing data, alignmen...
Article
Human endometrium undergoes cycles of proliferation and differentiation throughout the reproductive years of women. The endometrial stem/progenitor cells contribute to this regenerative process. They lie in the basalis layer of the endometrium next to the myometrium. We hypothesized that human myometrial cells provide niche signals regulating the a...
Article
Background: The management of the pregnancy after delivery of the first fetus during a second-trimester miscarriage or very early preterm birth has not been well defined. Objective: The objective of the study was to evaluate whether delayed interval delivery of the remaining fetus(es) in twins/triplets is associated with improved survival, when...
Article
Introduction Balanced reciprocal translocation is one of the most common chromosomal abnormalities in humans. Carriers are usually phenotypically normal but are at an increased risk of infertility, recurrent miscarriage or having affected children. Preimplantation genetic testing for chromosomal structural rearrangement (PGT-SR) offers a way to scr...
Article
We appreciate the comments from Vyas et al. (1) Although our study demonstrated that prediction of infants' immunoprophylaxis failure (IF) is possible in early pregnancy, whether women with extremely high viral load require earlier antiviral treatment for prevention of IF remains unknown.(2) Two randomized controlled trials showed no cases of IF (0...
Chapter
Ultrasound examination of the endometrium is a noninvasive method to evaluate the endometrium during in vitro fertilization (IVF). A good blood supply towards the endometrium is usually considered to be an essential requirement for implantation, and assessment of endometrial blood flow may therefore predict the IVF outcomes. Doppler flow of uterine...
Article
Objectives: To compare the proportion of women having a desired ovarian response following ovarian stimulation with gonadotrophin dosing determined based on AFC versus serum AMH level in women undergoing IVF using the GnRH antagonist protocol. Methods: This was a randomised double-blinded trial carried out in a university-affiliated assisted rep...
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Introduction: Authorities publish recommendations on the hepatitis B virus (HBV) viral load threshold to initiate antiviral treatment but the timing of quantification during pregnancy is not well defined. HBV DNA levels in pregnancy women at 28-30 weeks predict the risk of immunoprophylaxis failure. This study compared and evaluated the correlatio...
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Background Transvaginal oocytes retrieval is an essential step in in-vitro fertilization treatment. There are different pain relief methods, but none has been shown to be superior than the others. Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological and non-invasive pain relief method. This study aims to compare the pain leve...
Article
Balanced reciprocal translocation carriers are usually phenotypically normal but are at an increased risk of infertility, recurrent miscarriage or having affected children. Preimplantation genetic testing on chromosomal structural rearrangement (PGT-SR) offers a way to screen against unbalanced embryos. Here, we demonstrated a new method to disting...
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Introduction Robertsonian translocations are among the most common balanced structural rearrangements seen in general population with a frequency in newborn surveys of about 1 in 1000. Rob (13q14q) accounts for around 75% of all Robertsonian translocations. Because of the trivalent formations during meiosis, phenotypically normal carriers of Robert...
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Aim: Increasing preimplantation genetic testing (PGT) cycles are being performed in Hong Kong. This study aims to evaluate the knowledge, attitude and ethical consideration of Chinese couples toward PGT. Methods: Couples requesting PGT between June 2013 and March 2014 were invited to complete a questionnaire. Results: Total 49 couples (49 wome...
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Study question: Does glycodelin-A (GdA) induce conversion of human peripheral blood CD16-CD56bright natural killer (NK) cells to decidual NK (dNK) cells to facilitate placentation? Summary answer: GdA binds to blood CD16-CD56bright NK cells via its sialylated glycans and converts them to a dNK-like cells, which in turn regulate endothelial cell...
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Purpose: To evaluate the effect of 12-month DHEA supplementation on menstrual pattern and ovarian reserve markers in women with premature ovarian insufficiency (POI) METHODS: This is a prospective observational study. Women with POI were given DHEA supplements (25 mg three times daily) for 12 months. Sonographic assessment for ovarian volume and a...
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Study question: Can anti-Müllerian hormone (AMH) automated immunoassays (Elecsys® and Access) be used interchangeably as a companion diagnostic for individualisation of follitropin delta dosing? Summary answer: The Access assay gives systematically higher AMH values than the Elecsys® assay which results in over 29% of women being misclassified t...
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Human varicella zoster virus (VZV) is a member of the herpes virus family and affects humans only. Information about the presence of the virus in the semen samples of men affected by chickenpox is rather limited in the literature. Here, we reported a husband was affected by VZV during in vitro fertilisation treatment of his wife treated in our cent...
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Exposure to maternal diabetes during fetal growth is a risk factor for the development of type II diabetes (T2D) in later life. Discovery of the mechanisms involved in this association should provide valuable background for therapeutic treatments. Early embryogenesis involves epigenetic changes including histone modifications. The bivalent histone...
Article
STUDY QUESTION Does the use of hCG as luteal phase support in natural cycle frozen embryo transfer (FET) increase the ongoing pregnancy rate? STUDY ANSWER The use of hCG in natural cycle FET did not improve the ongoing pregnancy rate. WHAT IS KNOWN ALREADY The use of luteal phase support in stimulated cycles has been associated with higher live-b...
Article
STUDY QUESTION How do the three new anti-Müllerian hormone (AMH) assay methods, manufactured by Beckman Coulter, Roche and Ansh Labs compare with each other and with the Gen II assay? SUMMARY ANSWER The three new AMH assays are well correlated among themselves and with the Gen II assay, although differences in calibration do exist. WHAT IS KNOWN...
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Background Miscarriage is a common complication of pregnancy occurring in 15–20 % of all clinically recognized pregnancies. Currently, there is still no good scientific evidence to support the routine use of progestogens for the treatment of threatened miscarriage because the existing studies were not large enough to show a significant difference a...
Article
Study question: Does ulipristal acetate (UPA) have similar efficacy as emergency contraception (EC) when administered before and after ovulation? Summary answer: The efficacy of UPA-EC was significantly better when administered before than after ovulation. What is known already: Levonorgestrel (LNG) is effective as EC only when administered be...
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Purpose of review: To review updated information on the influence of endometrial scratching on IVF. Recent findings: Endometrial receptivity remains an important rate-limiting step affecting the success of IVF. The current evidence on the effect of endometrial scratching on IVF ranges from marked improvement, no difference to a potentially negat...
Article
Objective: To evaluate if letrozole-induced suppression of estradiol reduces progesterone receptor expression and apoptosis in the first trimester placenta. Study design: We performed a double-blinded, randomized, placebo-controlled trial. We randomized 20 women requesting first trimester abortion with gestation up to 63 days to receive either l...
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Objective: To evaluate the association of serum adiponectin level with the metabolic syndrome in Chinese women with polycystic ovary syndrome (PCOS). Methods: This was a cross-sectional study carried out in Hong Kong Chinese women with PCOS at a university-affiliated tertiary hospital between January 2010 and January 2011. Clinical and biochemic...
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The occurrence of tubal ectopic pregnancy (tEP) is related to the inflammation of the oviduct. Recently, Adrenomedullin (ADM) was found highly expression in human oviduct. The current study is to investigate whether ADM have a modulatory action on inflammatory cytokines and chemokines in oviductal tissue from women with tubal ectopic pregnancy (tEP...
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Objectives To evaluate the efficacy of local lidocaine gel and intrauterine lidocaine infusion in reducing pain level during saline infusion sonogram (SIS).Methods This is a randomized, double-blinded, placebo controlled trial. 120 recruited women were randomized into one of the following three groups: (1) 3 ml of 2% lidocaine gel on the cervix and...
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Should fasting glucose (FG) or an oral glucose tolerance test (OGTT) be used to screen for dysglycaemia in women with polycystic ovary syndrome (PCOS)? A full OGTT should be recommended as the screening method for dysglycaemia in women with PCOS, regardless of BMI or family history of diabetes mellitus (DM). A cross-sectional study on 467 Chinese w...
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The aim of this study is to investigate how women with different diagnoses on their cause of infertility—non-idiopathic (female, male, mixed), or idiopathic (unknown causes)—display different levels of psychosocial well-being prior to their IVF treatment. Women who attended an assisted reproduction clinic were recruited to fill out a set of questio...