Tak Yuen Fung

Trends in maternal obesity and associated risks of adverse pregnancy outcomes in a population of Chinese women.

Objective  To assess the effect of increasing body mass index (BMI) on pregnancy outcome in a population of Chinese women.

Fetal intra‐abdominal umbilical vein varix: what is the clinical significance?

To assess the clinical significance of fetal intra‐abdominal umbilical vein (FIUV) varix.

Prediction of birth weight by fetal crown-rump length and maternal serum levels of pregnancy-associated plasma protein-A in the first trimester

To determine whether the first trimester crown–rump length (CRL), maternal serum levels of pregnancy‐associated plasma protein A (PAPP‐A) and free beta‐human chorionic gonadotropin (fβ‐hCG) are independent predictors of birth weight.

Which ultrasound or biochemical markers are independent predictors of small-for-gestational age?

To investigate which ultrasound or biochemical markers in both the first and the second trimesters are the best predictors for fetal growth and small‐for‐gestational age (SGA).

Higher Median Levels of Free β-hCG and PAPP-A in the First Trimester of Pregnancy in a Chinese Ethnic Group

Objective: To study the effect of ethnic Chinese on the medians of free β-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). Results: The maternal serum levels of multiples of median of free β-hCG and PAPP-A were significantly higher among the Chinese than among the Caucasians. The weight-adjusted gestation-specific medians were developed. Without adjustment for ethnicity, the original FMF algorithm underestimated the risk of Down syndrome by a median of 1%. Adjustment by ethnicity increased the false-positive rate by 10% (from 5.3 to 5.9%). Conclusion: Ethnic Chinese have a significantly higher maternal serum level of free β-hCG and PAPP-A in the first trimester, which could not be explained by differences in maternal weight. Adjustment for ethnicity may be necessary for these biochemical markers in a first trimester screening program.

First-trimester combined screening for trisomy 21 in a predominantly Chinese population

To examine the effectiveness of first‐trimester fetal trisomy 21 screening using a combination of maternal age, nuchal translucency thickness (NT) and maternal serum free beta‐human chorionic gonadotropin (β‐hCG) and pregnancy‐associated plasma protein‐A (PAPP‐A) levels in a predominantly Chinese population in Hong Kong.

First trimester combined screening for Trisomy 21 in Hong Kong: outcome of the first 10,000 cases

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 β-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. All women were followed up for pregnancy and fetal outcome. Results. 10,363 fetuses underwent screening. 99% of the women were Chinese and 27.4% were at or above 35 years old. 618 fetuses were screened positive (5.9%), which included 31 cases of T21, 14 cases of T18, 7 cases of T13, 10 cases of 45XO and 7 cases of other chromosomal abnormalities. Among the 9745 screened negative fetuses all but 50 (0.5%) had a known outcome, which included three T21 and four other chromosomal abnormalities. All were subsequently identified at the morphology scan except for one case of T21. The detection rate and false positive rates for T21 were 91.2% and 5.4%, respectively and the positive predictive value for all chromosomal abnormalities was 1 in 9. Conclusions. Combined screening for T21 is highly effective among Chinese women. Training, quality control, regular auditing and follow up are essential to maintain screening standards.

Seasonal variation in pre-eclamptic rate and its association with the ambient temperature and humidity in early pregnancy.

Aims: To determine any relationship between ambient temperatures adjusted for humidity at conception and the occurrence of pre-eclampsia. Methods: The subjects were singleton primiparae delivered in a Teaching Hospital between 1995 and 2002. We studied the odds of developing pre-eclampsia across months and investigated the association between the pre-eclamptic rates based on the months of conception and the mean monthly heat index. Results: A total of 245 (1.6%) women were diagnosed pre-eclampsia and eclampsia during the study period. There was a significant association between the seasons of conception and rate of pre-eclampsia (logistic regression Wald χ2 = 9.2, p = 0.03). Conceptions during summer had a higher risk of pre-eclampsia than those during autumn (2.3 vs. 1.6%, OR 1.7, 95% CI 1.2–2.5). Women who conceived in June had the highest risk of developing pre-eclampsia (OR 2.8, 95% CI 1.5–5.2) while women who conceived in October had the lowest after adjusting for age. A 2-month time lag was observed between the peak pre-eclamptic rate in women who conceived in June and the peak heat index in August. Conclusion: Singleton primiparous women who conceived in summer and had a longer exposure to higher ambient temperature were at a greater risk of pre-eclampsia.

Homozygous alpha-thalassemia associated with hypospadias in three survivors.

We report three cases of homozygous alpha-thalassemia (alphaTH) who survived beyond the neonatal period, all with hypospadias. A review of literature identified two additional male cases of homozygous alphaTH who survived, and both had hypospadias. The simultaneous occurrence of the two conditions seems beyond coincidence and may be causally related. Possible pathogenesis for the association may be 1) homozygous alphaTH-induced in utero and/or edema secondary to hydrops fetalis, both leading to the failure of proper fusion of the urogenital folds, or 2) defect of another gene located at a chromosome 16p13.3 region. Thus, parents who request intrauterine therapy for a male fetus with homozygous alphaTH should be informed about this association and its prognosis.

Volumetric (3D) imaging reduces inter‐ and intraobserver variation of fetal biometry measurements

To compare the inter‐ and intraobserver variation of fetal biometric measurements utilizing two‐dimensional (2D) and three‐dimensional (3D) ultrasound imaging.