multiple gestation


multiple gestation

The presence of two or more embryos in the uterus. Twin and higher gestations have greatly increased in the past two decades due to the increased use of ovulation induction agents and assisted reproduction technologies. Currently 3% of all births are multiple gestations. When twins are diagnosed by ultrasound early in the first trimester, in about half of these cases one twin will silently abort, and this may or may not be accompanied by bleeding. This phenomenon has been termed the vanishing twin. The incidence of birth defects in each fetus of a twin pregnancy is twice that in singular pregnancies. Triplet, quadruplet, and higher gestation pregnancies are usually a result of commonly used fertility drugs. Multiple gestations are associated with an increased risk of perinatal morbidity and mortality. See also: gestation