Objective To compare the effectiveness of a nuchal scan at 10 to 14 + 6 weeks and a detailed morphology scan at 12 to 14 + 6 weeks in screening for fetal structural abnormalities. November 2004, 8811 pregnant women were randomized into either the control group (10 to 14 + 6-week nuchal scan followed by routine 16-23-week scan) or the study group (10 to 14 + 6-week nuchal scan and 12 to 14 + 6-week detailed scan followed by routine 16-23-week scan). Methods From March 2001 to ResultsWe analyzed 7642 cases of singleton pregnancies with viable fetuses at first-trimester ultrasound examination and with known pregnancy outcome. In the control group, the detection rate of structural abnormalities in the first trimester was 32. 8% (21/64; 95% CI, and the overall detection rate was 64.1% (41/64; 95% CI,). In the study group, the detection rate in the first trimester was 47.6% (30/63; 95% CI,) and the overall detection rate was 66.7% (42/63; 95% CI,

Although there were statistically significant differences in NT measurements between different ethnic groups, it was clinically insignificant, as reflected by similar screen-positive rates.

Pregnancies complicated with meconium-stained liquor are regarded as at risk of fetal distress. Evidence from animal and human studies indicate that passage of meconium may be related to fetal maturity. This retrospective study attempts to quantify the relative risk of non-reassuring cardiotocography or 'fetal distress' in pregnant women complicated by meconium-stained liquor for preterm, term and post-term pregnancies. A total of 9542 singleton pregnancies, delivered in a tertiary obstetric unit in Hong Kong between 1 July 1996 and 31 June 1999, were included in the study. Of these pregnancies, 1946 (20.4%) were identified as having meconium-stained liquor, ranging from thin to thick staining. There was a strong association between incidence of meconium-stained liquor (P < 0.0005) and moderate/thick meconium-stained liquor with advanced gestational age. The incidence of non-reassuring cardiotocography in women presenting with meconium-stained liquor was significantly higher (9.8% vs. 6.4%). The relative risk of non-reassuring cardiotocography in women with meconium-stained liquor increased with more advanced gestation. Close fetal surveillance during labour is required among these pregnancies. Premature labour is associated with higher incidence of fetal distress but the presence of meconium did not pose an additional risk.

Recent data have suggested that fetal nuchal translucency (NT) is affected by fetal gender. We investigated the size of this effect in 12 189 unselected pregnancies with known normal outcomes that had undergone NT measurements between 10 and 14 weeks of gestation. NT increased with gestation and was converted to multiples of the median (MoM) for the gestational day. The median NT MoM (95% CI) for female fetuses was 0.98 (0.97-0.99). This was significantly lower than that of the male fetuses (1.03; range 1.02-1.04) (p<0.0005; Wilcoxon rank-sum test). The gender difference was not observed at 10 weeks but was observed from 11 weeks onwards. There is no obvious explanation for the above findings.

Objective: To evaluate the accuracy and assess the indications of fetal echocardiography to diagnose structural heart disease in our high risk population, by an obstetric team. Methodology: Over a 4-year period, a transabdominal echocardiography was performed in 912 high risk pregnancies for congenital heart disease at 18-38 weeks of gestation. In the last 140 cases, an early examination combining either the transvaginal or the transabdominal route at 13-16 weeks was also carried out. Follow up was obtained from neonatal examinations and autopsies. The main indications for referral were: pregestational diabetes mellitus, family risk, increased nuchal translucency, suspected cardiac anomaly at screening ultrasound, women at high risk of chromosomal abnormality reluctant to invasive test, suspected arrhythmia, single umbilical artery, exposure to teratogens, and pregnancies affected by a chromosomal abnormality. Results: There were 79 (8.6%) major congenital heart defects, and most of them were yielded in the group of screening by ultrasound. Seventy of them (88.6%) were diagnosed correctly as abnormal prenatally. Atrioventricular septal defects (21 cases) and hypoplastic left ventricle syndrome (12 cases) were the most prevalent heart anomalies in the fetus. Isolated septal defects and coarctation of the aorta were the most difficult lesions to detect, being the ones with false positive and negative diagnosis. Another four cases of non-significant (<3 mm, no surgery nor medical treatment required) ventricular septal defects were overlooked during gestation, but closed by the sixth month of life. Fifteen apparently normal cases were lost to follow up. Conclusion: Our obstetric team results, in accordance with others previously published, show a good effectiveness to diagnose congenital heart anomalies. Most major detectable cardiac anomalies occur in the group without previously-known risk. Fetal echocardiography is optimized by a team strategy of imaging by obstetricians/high risk obstetric scanners (O) and fetal pediatric cardiologists (FPC). We retrospectively examined 1037 studies (1995)(1996)(1997)(1998)(1999), and identified 249 cases of major congenital heart disease. The O diagnosis was compared to the FPC diagnosis and postnatal diagnosis. The rate of complete accurate diagnosis for O and FPC diagnosis were 59% (17% false positive, 41% negative), respectively. Major differences in diagnosis or detail were found in 79 patients after FPC was completed and in 35/79 (44%) this was judged to have potential significant impact on management and prognosis counseling. The complementary roles of O and FPC remain important. FPC can contribute with additional detail in some cases which may significantly impact on counselling and planning. F03Factors influencing the prenatal detection of structural congenital heart diseases S.-F. Wong, F.-Y. Chan, R. Cincotta, A. Lee-Tannock & C. Ward Background: Congenital heart disease is the commonest congenital anomaly, but the reported antenatal detection rate varies widely from ...