Quality of nuchal translucency measurements in multifetal pregnancies

Objective. A prospective comparative study was conducted to investigate the effect of multifetal pregnancies on the quality of nuchal translucency measurements using an image scoring method. Methods. The study sample included 72 consecutive multiple gestations (164 fetuses) and 195 singleton gestations (control) matched for maternal age and fetal crown-rump length. Nuchal translucency ultrasound was performed similarly in singleton and multiple pregnancies. A single sonographer scored an elected ultrasound image of each fetus according to a nuchal translucency image scoring method and the mean image score was compared between the whole singleton and multiple gestation groups and between subgroups defined by fetal distance from the abdominal wall. Results. There was no significant difference in mean image score between the multiple and singleton gestation groups (6.60±1.3 and 6.69±1.5, respectively; p=0.595). Within the multiple gestation group, there was a significant difference in mean score between fetuses positioned proximal to the abdominal wall (n=72) (3.7±1.1) and both the middle fetuses (6.2±1.4; p<0.01) and distal fetuses (5.7±1.06; p<0.008). There was no difference between the proximal fetuses and controls. Conclusions. The fetuses in multiple pregnancies that are located further from the abdominal wall have a poorer image score.