A comparative study of multifetal pregnancy reduction from triplets to twins in the first versus early second trimesters after detailed fetal screening.

Abstract

To compare the outcome of multifetal pregnancy reduction from triplets to twins performed either early (at 11-12 weeks' gestation) or late (at 13-14 weeks). Ninety-five high-order pregnancies following assisted conception were studied. Transabdominal sonographically guided multifetal pregnancy reduction was performed early in 46 women, while 49 women first underwent a sonographic fetal anomaly scan before undergoing selective reduction. Sonographic screening led to selective termination of a specific fetus in nine cases due to increased nuchal translucency and relative intrauterine growth restriction in three cases each, and meningomyelocele, abdominal cyst and cystic hygroma in one case each. In the early reduction group a diagnosis of hypoplastic left heart in the two remaining twins was subsequently made, and one pair of twins suffers from cerebral palsy. The rate of pregnancy loss was not statistically different between the early (4.3%; 2/46) and late (4.0%; 2/49) termination groups. The birth weight and gestational age at birth were not statistically different between the early ( n = 85) and late ( n = 94) groups (2110 +/- 580 vs. 2140 +/- 490 g, and 35.8 +/- 3.0 vs. 35.7 +/- 3.5 weeks). Similarly there was no statistically significant difference between early and late groups in the incidence of very premature (24-32 weeks; 9.3 vs. 8.3%) and premature (33-36 weeks; 46.5 vs. 47.9%) births. Early second-trimester multifetal pregnancy reduction from triplets to twins may allow more selective termination of abnormal fetuses without an adverse effect on the outcome of pregnancy. However, further studies are needed in order to confirm our observations in a larger series.