Multiple births—the delivery of twins is common with fertility treatments. During the use of assisted reproductive technology (ART)—such as in-vitro fertilization (IVF)—multiple births primarily result from the transfer of more than one embryo during the procedure.

Multiple gestations increase maternal morbidity and fetal and neonatal morbidity and mortality. The most important maternal complications associated with multiple gestations are hyperemesis, preeclampsia, gestational diabetes, placenta praevia, and preterm labor and delivery. Other complications of multiple gestations include cholestasis, dermatoses, excess weight gain, anemia, hyperemesis gravidarum, and exacerbation of pregnancy-associated gastrointestinal symptoms (reflux, constipation). Chronic back pain, intermittent dyspnea, postpartum laxity of the abdominal wall, and umbilical hernias also occur frequently. Most of the excess perinatal morbidity and mortality associated with multiple gestations are directly related to the consequences of preterm birth.

Cervical cerclage is a prophylactic surgical procedure done to prevent preterm delivery.