Objectives: To derive a model and examine the performance of first‐trimester combined screening by maternal age, fetal nuchal translucency (NT) thickness and maternal serum free beta‐human chorionic gonadotropin (β‐hCG) and pregnancy‐associated plasma protein‐A (PAPP‐A).Methods: Prospective combined screening for trisomy 21 was carried out at 11 + 0 to 13 + 6 weeks in 56 771 singleton pregnancies, including 56 376 cases with a normal karyotype or delivery of a phenotypically normal baby (unaffected group) and 395 cases with trisomy 21. The blood test and ultrasound scan were carried out in the same visit. In each case the maternal age‐related risk for trisomy 21 at term was calculated and adjusted according to the gestational age at the time of screening to derive the a‐priori risk. The measured NT was transformed into a likelihood ratio using the mixture model of NT distributions. The measured free β‐hCG and PAPP‐A were converted into a multiple of the median (MoM) for gestational age, adjusted for maternal weight, ethnicity, smoking status, method of conception and parity, and a likelihood ratio was subsequently calculated. The likelihood ratios for NT and for the biochemical markers were multiplied by the a‐priori risk to derive the patient‐specific risk. Detection rates and false‐positive rates were calculated by taking the proportions with risks above a given risk threshold after adjustment for maternal age according to the distribution of pregnancies in England and Wales in 2000–2002. These standardized rates were compared with detection and false‐positive rates estimated using Monte Carlo methods to sample from the modeled Gaussian distributions.Results: The performance of screening based on the model was in good agreement with that observed in our population. In a strategy for first‐trimester combined screening where the blood test and scan are carried out in the same visit it was estimated that, for false‐positive rates of 3% and 5%, the detection rates were 92% and 94%, respectively, at 11 weeks, 85% and 90% at 12 weeks, and 79% and 83% at 13 weeks. In an alternative strategy, with the blood taken at 10 weeks and the measurement of NT performed at 12 weeks, the estimated detection rates were 94% and 96% for false‐positive rates of 3% and 5%, respectively.Conclusions: The aim of the first‐trimester scan is not just to screen for trisomy 21 but also to diagnose an increasing number of fetal malformations. In this respect the ability to visualize fetal anatomy is better at 12–13 weeks than at 11 weeks. Consequently, the ideal gestation for combined testing in the same visit would be 12 weeks. An alternative strategy, with the blood taken at 10 weeks and the measurement of NT performed at 12 weeks, is associated with higher detection rates of trisomy 21. However, the cost of two‐stage screening would be higher and, in addition, the potential advantage in terms of detection rate may be eroded by the likely increased non‐compliance with the additional step. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.

OBJECTIVE. The goal was to examine the carbohydrate tolerance and cardiometabolic risk among children exposed to maternal gestational diabetes mellitus in utero.METHODS. In this study, 164 Chinese children whose mothers had participated in a previous study on the screening and diagnosis of gestational diabetes mellitus (63 had gestational diabetes mellitus and 101 had normal glucose tolerance during the index pregnancies) underwent follow-up evaluations at a median age of 8 years (range: 7–10 years). Children's weight, height, hip and waist circumferences, and blood pressure were measured, and weight-adjusted oral glucose tolerance tests were performed.RESULTS. Six children (3.7%) demonstrated impaired glucose regulation or diabetes mellitus at the follow-up evaluation. Children exposed to maternal gestational diabetes mellitus had significantly higher systolic (94 ± 1.2 vs 88 ± 0.9 mmHg) and diastolic (62 ± 0.8 vs 57 ± 0.6 mmHg) blood pressure values and lower high-density lipoprotein cholesterol (1.58 ± 0.04 vs 1.71 ± 0.03 mmol/L) levels, after adjustment for age and gender. A high (≥90th percentile) umbilical cord insulin level at birth was associated with abnormal glucose tolerance in the offspring.CONCLUSIONS. Maternal gestational diabetes mellitus increases the offspring's cardiometabolic risk, and in utero hyperinsulinemia is an independent predictor of abnormal glucose tolerance in childhood.

Objectives: To construct new reference charts and equations for fetal biometry in the Hong Kong ethnic Chinese population, and to compare them with existing references from different populations.Methods: This was a prospective observational study involving 709 women with singleton pregnancies and confirmed gestational age. For the purposes of this study, each woman was scanned once only, between 12 and 40 completed weeks of gestation, and the following fetal biometric measurements were recorded: biparietal diameter, head circumference, abdominal circumference and femur length. For each measurement, regression models were fitted to estimate the mean and SD at each gestational age. For comparison, the fetal biometric measurements of other populations at each gestation were expressed as Z‐scores calculated with our reference equations. Results were presented graphically across the different gestational ages to allow visual comparison.Results: New charts and reference equations are reported in this Hong Kong Chinese population for fetal outer–inner and outer–outer biparietal diameter, head circumference, abdominal circumference and femur length. Equations for dating of pregnancy are presented. Our charts were very similar to those of the Singaporean population for most parameters. The main difference in our fetal biometric measurements compared with those of the UK and French populations was in FL.Conclusions: Our new set of reference centiles for fetal biometric measurements and equations for dating of pregnancy in a Hong Kong Chinese population are ready for clinical use and research in appropriate ethnic Chinese groups. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.