Second tier non-invasive prenatal testing in a regional prenatal diagnosis service unit: a retrospective analysis and literature review.

INTRODUCTION: The Hong Kong Hospital Authority has newly introduced a new Down's syndrome screening algorithm that offers free-of-charge non-invasive prenatal testing (NIPT) to women who screen as high risk. In preparation for this public-funded second tier NIPT service, the present study was conducted to retrospectively analyse women eligible for NIPT and to review the local literature. METHODS: Our retrospective study included women screened as high risk for Down's syndrome (adjusted term risk ≥1:250) during the period of 1 January 2015 to 31 December 2016. We performed descriptive statistics and multivariable logistic regression to examine the factors associated with women's choice between NIPT and invasive testing. We also reviewed existing local literature about second tier NIPT. RESULTS: The study included 525 women who screened positive: 67% chose NIPT; 31% chose invasive diagnostic tests; and 2% declined further testing. Our literature review showed that in non-research (self-financed NIPT) settings, NIPT uptake rates have been increasing since 2011. Nulliparity, first trimester status, higher education, maternal employment, and conception by assisted reproductive technology are common factors associated with self-financed NIPT after positive screening. Among women choosing NIPT, the rates of abnormal results have typically been around 8% in studies performed in Hong Kong. CONCLUSION: Implementation of second tier NIPT in the public setting is believed to be able to improve quality of care. We expect that the public in Hong Kong will welcome the new policy.

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.

Indications for and pregnancy outcomes of cervical cerclage: 11-year comparison of patients undergoing history-indicated, ultrasound-indicated, or rescue cerclage.

OBJECTIVES: To review and compare pregnancy outcomes of patients undergoing history-indicated, ultrasound-indicated, or rescue cerclage. DESIGN: Case series with internal comparison. SETTING: A regional obstetric unit in Hong Kong. PATIENTS: Women undergoing cervical cerclage at Kwong Wah Hospital between 1 January 2001 and 31 December 2011. INTERVENTIONS: Cervical cerclage. MAIN OUTCOME MEASURES: Pregnancy outcomes including miscarriage, gestational age at delivery, birth weight, and duration of pregnancy prolongation. RESULTS: Overall, 47 patients were included. Nine (19.1%) pregnancies resulted in miscarriage. The median gestational age at delivery was 35.7 weeks. Among the 23 patients who had history-indicated cerclage, only four (17.4%) had three or more previous second-trimester miscarriages or preterm deliveries. Among the 15 patients who had ultrasound-indicated cerclage, preoperative cervical length of ≤1.5 cm was associated with shorter prolongation of pregnancy, compared with that of >1.5 cm (median, 12.1 vs 18.4 weeks; P=0.009). Among the nine women who had rescue cerclage, those who underwent the procedure before 20 weeks of gestation delivered earlier than those underwent cerclage later (median, 22.5 vs 34.1 weeks; P=0.048). CONCLUSIONS: Patients eligible for the Royal College of Obstetricians and Gynaecologists-recommended history-indicated cerclage remain few. The majority of patients may benefit from serial ultrasound monitoring of cervical length with or without ultrasound-indicated cerclage.

Intensive care unit admission of obstetric cases: a single centre experience with contemporary update.

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.

Social obstetrics: non-local expectant mothers admitted through accident and emergency department in a public hospital in Hong Kong.

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'.

Predictors of successful outcomes after external cephalic version in singleton term breech pregnancies: a nine-year historical cohort study.

OBJECTIVE: To study the success rate, predictors for success, and pregnancy outcomes after external cephalic version. DESIGN: Historical cohort study. SETTING: Regional hospital, Hong Kong. PATIENTS: 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. MAIN OUTCOME MEASURES: Predictive factors for successful external cephalic version. RESULTS: 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%. CONCLUSION: 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.

Factors influencing the mode of delivery and associated pregnancy outcomes for twins: a retrospective cohort study in a public hospital.

OBJECTIVES: To determine current trends for different modes of delivery in twin pregnancies, factors affecting the mode of delivery, and associated outcomes. DESIGN: Retrospective cohort study. SETTING: A public hospital in Hong Kong. PARTICIPANTS: All twin pregnancies booked at Kwong Wah Hospital during a 3-year period from 1 April 2006 to 31 March 2009. RESULTS: 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. CONCLUSION: 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.

Successful treatment of severe fetal chylothorax resistant to repeated pleuroamniotic shunting by OK-432 pleurodesis.

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.

Is ultrasound alone enough for prenatal screening of trisomy 18? A single centre experience in 69 cases over 10 years.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Screening options for Down syndrome: how women choose in real clinical setting.

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Monozygotic dichorionic twins heterokaryotypic for duplication chromosome 2q13-q23.3.

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.

Rapid aneuploidy testing (knowing less) versus traditional karyotyping (knowing more) for advanced maternal age: what would be missed, who should decide?

OBJECTIVES: 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. DESIGN: Retrospective study on a cytogenetic database. SETTING: Eight public hospitals in Hong Kong. PARTICIPANTS: 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. RESULTS: 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. CONCLUSIONS: '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.

Obstetric cholestasis in Hong Kong--local experience with eight consecutive cases.

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.

Two cases of postmaturity-related perinatal mortality in non-local expectant mothers.

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.

Sublingual misoprostol compared to artificial rupture of membranes plus oxytocin infusion for labour induction in nulliparous women with a favourable cervix at term.

OBJECTIVES: To compare the efficacy of labour induction using sublingual misoprostol versus combined artificial rupture of membranes and oxytocin infusion for nulliparous women with a favourable cervix at term. DESIGN: Open randomised controlled trial. SETTING: Regional hospital, Hong Kong. PATIENTS: Fifty nulliparous women with a favourable cervix (Bishop score 6 or more) at term and indications for labour induction. INTERVENTIONS: With their informed consent, 100 eligible women were to be randomised to receive either sublingual misoprostol 50 micrograms every 4 hours for up to five doses or oxytocin infusion after artificial rupture of membranes. Interim analysis was planned at a sample size of 50. MAIN OUTCOME MEASURES: Vaginal delivery within 24 hours of induction. RESULTS: The study was terminated when interim analysis of the first 50 recruits showed that a significantly smaller proportion of misoprostol-treated women delivered vaginally within 24 hours of induction than in the conventional treatment group (68% vs 100%; relative risk, 0.68; 95% confidence interval, 0.51-0.91; P=0.009), although comparable numbers of women eventually delivered vaginally. The mean induction to vaginal delivery interval was 4.5 hours longer in the misoprostol group (P=0.027). After misoprostol treatment, all women went into labour. Forty percent of them delivered without oxytocin. There was no significant difference in uterine hyperstimulation rate, operative delivery rate, and neonatal outcomes. Maternal satisfaction was higher in the misoprostol group (92% vs 60%; relative risk, 1.53; 95% confidence interval, 1.09-2.16; P=0.008). CONCLUSIONS: Despite being well accepted by women, labour induction using this regimen of sublingual misoprostol is less effective in achieving vaginal delivery within 24 hours.