Medical, ethical, and legal aspects of fetal reduction

We expect the vast majority of patients with twins to continue with twins. However, there is a continually increasing proportion of the infertility population, particularly those over 40 years of age, who for a variety of medical and social reasons want to have only a singleton pregnancy. Our data suggest that for such patients, MFPR is safer than continuing with twins. As with all other technologies, as its safety and effi cacy have been proven, indications will liberalize. In the 1980s and '90s, as MFPR was being developed and improved, there was little debate, except among the most strident opponents, that MFPR from quadruplets or more was the best way to improve outcomes in such cases. In the last decade, the major debate was over the outcome of triplets. Several studies have addressed that issue, and those with the most data suggest improved outcomes with reduction of triplets to twins. Interestingly, reduction of triplets to a singleton has a higher loss rate (7% versus 4.5%) but lower morbidity, yet both resultant twins or singletons are much less risky than attempting to carry the triplets (15%) (Adashi et al. 2003). However, for those patients starting with twins, reducing from twins to a singleton seems to signifi cantly lower risks and improve outcomes.