Live-birth rates and multiple-birth risk using in vitro fertilization.

Abstract

Since the goal of in vitro fertilization (IVF) is pregnancy and, ultimately, live birth, clinical decision making about IVF practices is heavily focused on maximizing a woman's chances of becoming pregnant. One common practice that aims to increase the likelihood of pregnancy is to transfer multiple embryos (often more than 3) into the uterine cavity. This treatment approach also presents an important drawback, however, because it increases the risk for multiple birth. Multiple-birth infants are at significant risk for a number of adverse outcomes including preterm delivery, low birth weight, congenital malformations, fetal and infant death, and long-term morbidity and disability among survivors.^1-5 Twins are 5 times as likely, and triplet and higher-order infants 13 times as likely, as singleton infants to die during the first year of life.²