W L Lau

Kwong Wah Hospital, Hong Kong, Hong Kong

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Publications (23)36.12 Total impact

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    ABSTRACT: Abstract Objective: To assess whether angle of progression (AOP) and head-perineum distance (HPD) measured by intrapartum transperineal ultrasound (ITU) correlate with clinical fetal head station (station); and whether AOP versus HPD varies during uterine contraction and relaxation. In a subset of primipaorus women, whether these ITU parameters correlate with time to normal spontaneous delivery (TD). Methods: We evaluated prospectively 100 primiparous and multiparous women at term in active labor. Transabdominal and transperineal ultrasound (sagittal and transverse plane) were used to measure fetal head position, and ITU parameters respectively. Digitally palpated station and cervical dilatation were also noted. The results were compared using regression and correlation coefficients. Results: Station was moderately correlated with AOP (r= 0.579), and HPD (r= -0.497). AOP was highly correlated with HPD during uterine contraction (r= -0.703) and relaxation (r= -0.647). In the subgroup of primiparous women, natural log of TD has the highest correlation with HPD and AOP during uterine contraction (r=0.742), making prediction of TD similar to that using cervical dilatation. Conclusion: ITU parameters were moderately correlated with station. There was constant high correlation between AOP and HPD. Prediction of TD in primiparous women using ITU parameters was similar to that using cervical dilatation.
    Journal of Maternal-Fetal and Neonatal Medicine 08/2014; DOI:10.3109/14767058.2014.958459 · 1.21 Impact Factor
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    ABSTRACT: A rebound increase in vaginal delivery for twins was observed in a regional obstetric unit in Hong Kong, reinforced by the results of a recent multicenter randomized controlled trial.
    International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics 07/2014; 126(1). DOI:10.1016/j.ijgo.2014.01.009 · 1.41 Impact Factor
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    ABSTRACT: OBJECTIVES. To review the pregnancy outcomes of non-booked, non-local pregnant women delivering in Kwong Wah Hospital via admission to the Accident and Emergency Department 1 year after the announcement by the Hospital Authority to stop antenatal booking for non-eligible persons; and to perform a literature review of local studies about non-eligible person deliveries over the last decade. DESIGN. Case series. SETTING. A public hospital in Hong Kong. PARTICIPANTS. All women who held the People's Republic of China passport or the two-way permit and those non-eligible persons whose spouses were Hong Kong Identity Card holders, who delivered in Kwong Wah Hospital from 1 April 2011 to 31 March 2012. RESULTS. Overall, 219 women who were non-eligible persons delivered 221 live births during the study period. Compared with the annual statistics of Kwong Wah Hospital in 2011, non-local mothers were of higher parity; more likely to have hypertensive disease (including pre-eclamptic toxaemia), preterm deliveries (ie at <37 weeks), babies needing admission to the special care baby unit, and macrosomic babies (ie weighing >4.0 kg). The rates of induction of labour and caesarean section were lower in this group. There was no significant difference in the maternal and neonatal outcomes between women who had no booking and those who had a booking in another Hospital Authority or private hospital. There were many incidents of near-miss obstetric complications or suboptimally managed obstetric conditions due to lack of well-structured and continuous antenatal care in this group of non-eligible persons. CONCLUSION. Non-eligible person delivering babies in Hong Kong has become a social obstetrics phenomenon. Despite the introduction of policies, reduction in the number of deliveries (quantity) did not improve the obstetric outcomes (quality). Health care professionals should continue to be prepared for managing the potential near-miss clinical complications in this group of 'travelling mothers'.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 05/2014; DOI:10.12809/hkmj134181
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    ABSTRACT: OBJECTIVES. To review the characteristics of a series of obstetric patients admitted to the intensive care unit in a regional hospital in 2006-2010, to compare them with those of a similar series reported from the same hospital in 1989-1995 and a series reported from another regional hospital in 1998-2007. DESIGN. Retrospective case series. SETTING. A regional hospital in Hong Kong. PATIENTS. Obstetric patients admitted to the Intensive Care Unit of Kwong Wah Hospital from 1 January 2006 to 31 December 2010. RESULTS. From 2006 to 2010, there were 67 such patients admitted to the intensive care unit (0.23% of total maternities and 2.34% of total intensive care unit admission), which was a higher incidence than reported in two other local studies. As in the latter studies, the majority were admitted postpartum (n=65, 97%), with postpartum haemorrhage (n=39, 58%) being the commonest cause followed by pre-eclampsia/eclampsia (n=17, 25%). In the current study, significantly more patients had had elective caesarean sections for placenta praevia but fewer had had a hysterectomy. The duration of intensive care unit stay was shorter (mean, 1.8 days) with fewer invasive procedures performed than in the two previous studies, but maternal and neonatal mortality was similar (3% and 6%, respectively). CONCLUSION. Postpartum haemorrhage and pregnancy-induced hypertension were still the most common reasons for intensive care unit admission. There was an increasing trend of intensive care unit admissions following elective caesarean section for placenta praevia and for early aggressive intervention of pre-eclampsia. Maternal mortality remained low but had not decreased. The intensive care unit admission rate by itself might not be a helpful indicator of obstetric performance.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 06/2013; DOI:10.12809/hkmj133924
  • T.K. Lo, T.K. Ng, W.L. Lau, W.C. Leung
    International Journal of Cardiology 04/2013; 164(2):S11-S12. DOI:10.1016/S0167-5273(13)70555-2 · 6.18 Impact Factor
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    ABSTRACT: To determine current trends for different modes of delivery in twin pregnancies, factors affecting the mode of delivery, and associated outcomes. Retrospective cohort study. A public hospital in Hong Kong. All twin pregnancies booked at Kwong Wah Hospital during a 3-year period from 1 April 2006 to 31 March 2009. Of 197 sets of twins, 35 (18%) were delivered vaginally and 162 (82%) by caesarean section (47% were emergencies and 53% elective). In all, 32 (37%) of the elective and 21 (28%) of the emergency caesarean sections were in response to maternal requests. Vaginal delivery was more common in mothers with a history of vaginal delivery and monochorionic diamniotic twins. Women who conceived by assisted reproduction or those who had a tertiary education were more likely to deliver by caesarean section. The type of conception and the presentation of the second twin were statistically significant factors affecting maternal choice on the mode of delivery. Maternal age did not affect the choice of delivery mode. Except for the higher frequency of sepsis and cord blood acidosis in second twins delivered vaginally, there were no significant differences in neonatal morbidity between the groups that attempted vaginal delivery or requested caesarean sections. All the women who had compression sutures or hysterectomy to control massive postpartum haemorrhage were delivered by caesarean section. A high caesarean section rate observed in our cohort was associated with maternal requests for this mode of delivery. The type of conception and the presentation of the second twin were statistically significant factors affecting maternal choice on mode of delivery. Women's requests for caesarean delivery out of the concern for their babies are not supported by current evidence. In response to a woman with a twin pregnancy requesting caesarean delivery, the pros and cons of vaginal deliveries and caesarean sections should be fully explained before the woman's autonomy is respected.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 04/2012; 18(2):99-107.
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    ABSTRACT: We report the first case of successful fetal pleurodesis with OK-432 for recurrent severe fetal primary chylothorax after failing repeated pleuroamniotic shunting. Shunting and pleurodesis could be complementary to each other in the treatment of fetal chylothorax.
    Fetal Diagnosis and Therapy 02/2012; 31(4):260-3. DOI:10.1159/000336125 · 2.30 Impact Factor
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    ABSTRACT: To study the success rate, predictors for success, and pregnancy outcomes after external cephalic version. Historical cohort study. Regional hospital, Hong Kong. All women who had singleton term breech pregnancies at term and opted for external cephalic version during 2001 and 2009. Their demographic data, clinical and ultrasound findings, procedure details, complications, and delivery outcomes were analysed. Predictive factors for successful external cephalic version. A total of 209 external cephalic versions were performed during the 9-year period. The success rate was 63% (75% for multiparous and 53% for nulliparous women). There was no significant complication. On univariate analysis, predictors of successful external cephalic version were: multiparity, unengaged presenting part, higher amniotic fluid index (≥ 10 cm), thin abdominal wall, low uterine tone, and easily palpable fetal head (subjective assessment by practitioners before external cephalic version). On multivariate analysis, only multiparity, non-engagement of the fetal buttock and thin maternal abdomen were associated with successful external cephalic version. In all, 69% of those who had successful external cephalic version succeeded in the first roll (P<0.001), and 82% of the women with successful external cephalic versions had vaginal deliveries (93% in multiparous and 69% in nulliparous women). Uptake rate of external cephalic version was studied in the latter part of the study period (2006-2009). Whilst 735 women were eligible for external cephalic version, 131 women chose to have the procedure resulting in an uptake rate of 18%. External cephalic version was effective in reducing breech presentations at term and corresponding caesarean section rates, but the uptake rate was low. Further work should address the barriers to the low acceptance of external cephalic version. The results of this study could encourage women to opt for external cephalic version.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 02/2012; 18(1):11-9.
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    ABSTRACT: To evaluate ultrasound scan and other prenatal screening tests for trisomy 18 in a regional obstetric unit and to review the management approach for women with positive trisomy 18 screening results. Prenatal diagnosis databases were accessed to identify fetuses that had confirmed trisomy 18 karyotypes or were at high risk for trisomy 18 on second-trimester biochemical screening or first-trimester combined screening tests over a period of 10 years from 1 September 1997 to 30 September 2007. Sixty-nine women were confirmed to have trisomy 18 fetuses by karyotyping either prenatally (n = 61) or postnatally/post-miscarriage (n = 8) during the study period. The detection rate of ultrasound scan ≤ 14 weeks and 18 to 21 weeks to detect trisomy 18 was 92.7 and 100%, respectively. A total of 80 and 87% of fetuses had two or more ultrasound abnormalities detected in the ≤ 14 weeks and 18 to 21 weeks anomaly scans, respectively. Forty-eight women screened positive for trisomy 18 by second-trimester biochemical screening with human chorionic gonadotrophin (hCG) and alpha fetoprotein (AFP). Only one was true positive (positive predictive value = 1/48 or 2%). Eleven women screened positive for trisomy 18 by first-trimester combined screening with nuchal translucency scan and maternal serum for pregnancy-associated plasma protein A (PAPP-A) and hCG between 11 and 13 + 6 weeks. Three were true positive (positive predictive value = 3/11 or 27%). All four cases with positive screening had ultrasound abnormalities. Ultrasound scan for fetal anomalies is the most effective screening test for trisomy 18. A policy of conservative management for women with positive second-trimester biochemical screening or first-trimester combined screening for trisomy 18 is reasonable in the absence of ultrasound fetal abnormalities. Unnecessary invasive tests can be avoided.
    Prenatal Diagnosis 10/2010; 30(11):1094-9. DOI:10.1002/pd.2623 · 2.68 Impact Factor
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    ABSTRACT: Before April 2006, women with singleton pregnancy and advanced maternal age (AMA, 35 years and older) were offered either direct invasive tests or a variety of screening tests for Down syndrome (DS) with routine anomaly scan at 18-20 weeks. After April 2006, to reduce procedure-related fetal loss, invasive test was performed only for positive screening result or the presence of major fetal anomaly on ultrasound. We reviewed our 2-year experience after the policy change. Two-year data after policy change were compared to the 1-year historic control before policy change. A total of 2257 eligible women were counselled in the 2 years after policy change. The uptake of screening was 96.7%. The overall detection rate for DS was 90% (18/20) at a false positive rate of 10.9%. The number of invasive tests performed to diagnose one case of DS was reduced 7-fold from 97 to 13. The number of direct invasive tests was markedly reduced. With effective DS screening policy, it is possible to do away with direct invasive testing for the majority of women with AMA.
    The journal of maternal-fetal & neonatal medicine: the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 11/2009; 23(8):914-9. DOI:10.3109/14767050903370327 · 1.36 Impact Factor
  • The journal of maternal-fetal & neonatal medicine: the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 09/2009; 23(7):747-9. DOI:10.1080/14767050903189016 · 1.36 Impact Factor
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    ABSTRACT: To study pregnant women's preference among various screening options for Down syndrome (DS) in routine clinical setting, and its potential association with women's demographic characteristics. Women aged 35 years and older carrying singleton pregnancy were offered a variety of screening tests for DS before 14 weeks of gestation. Their preference was confirmed by the test they actually underwent. The association between women's choice of test and a number of demographic characteristics was studied using multinomial regression. Among 1967 eligible women, 619 opted for first-trimester screening test (FTS), 924 for partial integrated test (PIT), and 424 for full integrated test (FIT). Nulliparous women and working mothers were more likely to choose FTS and FIT. Women with history of subfertility were more likely to choose FIT. Women with family history of chromosomal abnormalities were more likely to choose FTS. The choice of screening test could be predicted for 49.9% of women using four demographic characteristics. Among older women of predominantly Chinese ethnicity, integrated test is a favorite alternative to FTS. Their choice of DS screening test can be predicted by their obstetric and socioeconomic characteristics. Many women show willingness to pay for a test with a lower false-positive rate.
    Prenatal Diagnosis 06/2009; 29(9):852-6. DOI:10.1002/pd.2292 · 2.68 Impact Factor
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    ABSTRACT: We present an evaluation of the diagnosis, management and outcome of a pair of heterokaryotypic monozygotic dichorionic twins. The heterokaryotype was an incidental finding from an amniocentesis performed for prenatal diagnosis of beta-thalassaemia major in a pair of dichorionic twins. Monozygocity was revealed by QF-PCR showing identical short tandem repeat markers on chromosomes 21, 18, 13, X and Y. The twins were heterokaryotypic for duplication chromosome 2q13-q23.3, as shown by array comparative genomic hybridization. Selective foeticide was performed. This case demonstrates that heterokaryotypic monozygotic dichorionic twins are a genetic possibility that does occur.
    Fetal Diagnosis and Therapy 01/2009; 25(4):397-9. DOI:10.1159/000236153 · 2.30 Impact Factor
  • International Journal of Gynecology & Obstetrics 09/2008; 102(2):176-8. DOI:10.1016/j.ijgo.2008.03.009 · 1.56 Impact Factor
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    ABSTRACT: To explore the effect of gestational age on the outcome of second-trimester termination of pregnancies for foetal abnormalities. A retrospective study was conducted on 280 pregnancies terminated for foetal abnormalities in the second trimester using vaginal misoprostol. The gestational age at termination was divided into three groups: 13-16 weeks, 17-20 weeks and 21-23 weeks. The likelihood of (1) abortion within 24 h of commencement of misoprostol, (2) incomplete abortion and (3) experiencing significant side effects was compared among these three gestational groups after adjusting for maternal age, parity and body mass index (BMI). Compared to termination after 20 weeks, pregnancy termination for foetal abnormality before 17 weeks of gestation was associated with higher chance of incomplete abortion (OR 2.2, 95% CI 1.07-4.61, p = 0.032) and lower chance of experiencing significant side effects (OR 0.11, 95% CI 0.01-0.91, p = 0.041). Women undergoing pregnancy termination for foetal abnormalities in the early second trimester should be informed of possible higher chance of incomplete abortion.
    Prenatal Diagnosis 07/2008; 28(6):508-11. DOI:10.1002/pd.2012 · 2.51 Impact Factor
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    ABSTRACT: To explore whether the outcomes of second-trimester pregnancy termination for fetal abnormalities are affected by fetal diagnoses. This was a retrospective review of cases undergoing second-trimester pregnancy termination for the fetal diagnoses of hemoglobin Barts, trisomy 21, and trisomy 18 during the period from 1999 to 2006. The affected pregnancies were terminated by vaginal misoprostol. The outcome measures were: (1) abortion within 24 hours after misoprostol commencement, (2) histology-confirmed incomplete abortion, and (3) experience of significant side effects during termination (temperature over 39 degrees C or need for metoclopramide for vomiting). One hundred and twenty cases were available for analysis. After adjusting for maternal age, parity, history of cesarean delivery, body mass index, gestation, and fetal hydrops, pregnancy termination for trisomy 21 was associated with a higher risk of incomplete abortion than trisomy 18 and hemoglobin Barts (odds ratio 5.25, 95% confidence interval 1.24-22.19, p = 0.024). The chance of abortion within 24 hours and experience of significant side effects were not found to be associated with fetal diagnosis. Pregnancy termination for trisomy 21 is associated with a higher risk of incomplete abortion. Fetal diagnosis affects the outcome of pregnancy termination.
    The journal of maternal-fetal & neonatal medicine: the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians 06/2008; 21(8):523-7. DOI:10.1080/14767050802104835 · 1.36 Impact Factor
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    ABSTRACT: The application of rapid aneuploidy testing as a stand-alone approach in prenatal diagnosis is much debated. The major criticism of this targeted approach is that it will not detect other chromosomal abnormalities that will be picked up by traditional karyotyping. This study aimed to study the nature of such chromosomal abnormalities and whether parents would choose to terminate affected pregnancies. Retrospective study on a cytogenetic database. Eight public hospitals in Hong Kong. The karyotype results of 19 517 amniotic fluid cultures performed for advanced maternal age (>or=35 years) from 1997 to 2002 were classified according to whether they were detectable by rapid aneuploidy testing. The outcomes of pregnancies with abnormal karyotypes were reviewed from patient records. In all, 333 (1.7%) amniotic fluid cultures yielded abnormal karyotypes; 175 (52.6%) of these were detected by rapid aneuploidy testing, and included trisomy 21 (n=94, 28.2%), trisomy 18 or 13 (n=21, 6.3%), and sex chromosome abnormalities (n=60, 18.0%). The other 158 (47.4%) chromosomal abnormalities were not detectable by rapid aneuploidy testing, of which 63 (18.9%) were regarded to be of potential clinical significance and 95 (28.5%) of no clinical significance. Pregnancy outcomes in 327/333 (98.2%) of these patients were retrieved. In total, 143 (42.9%) of these pregnancies were terminated: 93/94 (98.9%) for trisomy 21, 20/21 (95.2%) for trisomy 18 or 13, 19/60 (31.7%) for sex chromosome abnormalities, and 11/63 (17.5%) for other chromosomal abnormalities with potential clinical significance. There were no terminations in the 95 pregnancies in which karyotyping results were regarded to be of no clinical significance. 'Knowing less' by the rapid aneuploidy stand-alone testing could miss about half of all chromosomal abnormalities detectable by amniocentesis performed for advanced maternal age. Findings from two fifths of the latter were of potential clinical significance, and the parents chose to terminate one out of six of the corresponding pregnancies. If both techniques are available, parents could have enhanced autonomy to choose.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 03/2008; 14(1):6-13.
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    ABSTRACT: Obstetric cholestasis is associated with maternal morbidity and adverse foetal outcomes. No information on local incidence is available. We present our experience with eight consecutive cases of obstetric cholestasis diagnosed between January 2003 and December 2005 in a regional hospital in Hong Kong. Three patients presented with pruritus without rash, three with impaired liver function, and two with elevated blood pressure postpartum. Meconium-stained liquor was present in five patients and four had spontaneous preterm delivery (between 34 and 36 weeks). The higher the bile acid level, the more marked the prematurity (correlation coefficient, -0.771; P=0.025). All those presenting with itchiness delivered preterm. Two patients developed pre-eclampsia. The rates of labour induction and abdominal delivery were both 38%. Heightened awareness among clinicians is required to recognise patients with obstetric cholestasis. Affected pregnancies are associated with meconium passage and prematurity. In our locality, affected women may also have an increased risk of pre-eclampsia. In affected women, the bile acid level is useful in assessing the risk of prematurity.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 11/2007; 13(5):387-91.
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    ABSTRACT: We present two cases of postmaturity-related perinatal mortality with delivery at 42 weeks 6 days' and 44 weeks' gestation, respectively. No cause beyond postmaturity was found. Neither induction of labour nor foetal monitoring had been performed despite these gestations going post 41 weeks because of a current 'social obstetrics' phenomenon--non-local expectant mothers coming to Hong Kong from mainland China for delivery.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 07/2007; 13(3):231-3.
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    W L Lau, H S W Lam, W C Leung
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    ABSTRACT: Increased uterine artery pulsatility and resistance indices with or without notching of the waveform have been associated with an increased risk of pre-eclampsia and fetal growth restriction. However, reversed diastolic flow in the uterine artery has not previously been reported. We present two high-risk obstetric cases complicated by severe placental insufficiency: pre-eclampsia followed by eclampsia in one case and intrauterine growth restriction with abnormal cardiotocography in the other. Doppler studies of the uterine arteries revealed reversed diastolic flow in both cases. The pathophysiology and potential implications are discussed.
    Ultrasound in Obstetrics and Gynecology 03/2007; 29(2):232-5. DOI:10.1002/uog.3872 · 3.14 Impact Factor