First trimester embryo reduction: a medical solution to an iatrogenic problem.

The incidence of multiple pregnancies is increasing, mainly as a consequence of the widespread use of various infertility protocols. Since such gestations present a high risk of feto-maternal morbidity and mortality, selective first trimester fetocide remains one of the few reasonable options. We reviewed the literature dealing with the outcome of 804 multiple pregnancies following the use of transcervical, transvaginal or transabdominal approaches. Questions relating to dealing with technical failure, method of fetocide and procedural improvements are examined. In a comparison of the variables: miscarriage, preterm delivery, perinatal and neonatal loss rates, the transvaginal approach fares better, but statistical significance (P < 0.001) is achieved only for preterm delivery. We speculated that this might be attributable to the very early gestational age at which the procedure is usually performed. However, the transabdominal approach offers better results when post-manipulation maternal morbidity is considered, i.e. infection and vaginal bleeding. Since each option offers different advantages and disadvantages, additional experience and larger population samples are required to further clarify this important issue.