Fertility doctors are beginning to wonder whether they're too successful. With in vitro fertilization prompting a 70% increase in the rate of multiple births since 1980, some are espousing a switch to single-embryo transfer. The procedure lowers the success rate but also lowers the rate of multiple births, with their attendant health risks, the New York Times reports.
“Now is the time for all of us to rethink what is the paradigm of a successful IVF pregnancy,” said a Boston fertility doc. “Is it a pregnancy without regard to the number of gestations or a pregnancy with a singleton live birth?” Reducing the number of embryos transferred has already cut the rate of triplets being born, but the twin birth rate remains high.