Fetal abnormalities leading to termination of singleton pregnancy: the 7-year experience of a single medical center.

Objective: To assess the distribution of fetal indications leading to termination of pregnancy (TOP) in our institute.

Methods: All pregnant women with singleton pregnancies who underwent TOP due to fetal abnormalities in our institute between January, 1998 and December, 2004 were divided between early TOP (<23 weeks' gestation) and late TOP (> or =23 weeks' gestation).

Results: There were 328 (71%) and 134 (29%) early and late TOPs, respectively. The TOPs were performed at a mean gestational age of 20.1 +/- 4.8 weeks. The groups varied significantly in the indications for TOP (p = 0.04), which were primarily structural abnormalities (mostly CNS) followed by chromosomal/genetic defects. Fetal structural abnormalities were more common in the late TOP group (62.7% vs 54.2%) while chromosomal-genetic defects were more common in the early TOP group (40% vs 29.1%, respectively). Fetal infection (mostly cytomegalovirus) was similar ( approximately 4%) for both groups. The early TOP group had significantly more hydrops, gastrointestinal, face and neck abnormalities, while the late TOP group had significantly more cardiovascular abnormalities (p < 0.01).

Conclusions: The impact of early chromosomal/genetic screening contributes to early TOPs, while midgestation anomaly and cardiac scanning significantly contribute to late TOPs. Fetal infection contributes equally to both categories of TOPs.