The prevalence of major CHD in this study was 3.5 per 1000, suggesting that ascertainment of CHD in our study population was thorough. Fetuses with NT measurements > or = 3.5 mm have a significantly increased risk of major CHD, and this identifies a subgroup of high-risk patients in whom early fetal echocardiography would be advocated. The low sensitivity of NT for major CHD in the general population, however, indicates that NT cannot be relied on as the sole or major screening tool for this condition as previously reported.

ABSTRACT

The aim of this study was to examine the effect of the inter-twin delivery interval on neonatal haemoglobin concentration. We retrospectively analysed 108 twin deliveries over a 5-year period. Chorionicity was determined by first trimester ultrasound or placental histopathology. The mode of delivery, time of delivery and cord/neonatal blood counts were recorded. A total of 88 sets of dichorionic and 20 sets of monochorionic twins were studied. There was no correlation between inter-twin delivery interval and haemoglobin difference (rho = 0.020, p = 0.857). In monochorionic twin pregnancies, there was a trend towards increasing inter-twin hemoglobin differences with prolonged delivery intervals. However, this trend did not reach statistical significance (rho = -0.303, p = 0.193). In monochorionic twins, there is a trend towards a lower haemoglobin concentration in the twin delivered second. This haemoglobin deficit appears to be related to the inter-twin delivery interval.