Multiple gestation

The human female is clearly programmed to ovulate a single oocyte, to carry a singleton fetus, and to nurse one neonate at a time. The infrequency of high-order multiple gestations might be understood from the quasi-mathematical relationship, known as the Hellin-Zellany rule for twins, triplets, and quadruplets. Iatrogenic multiple gestations, the major contributors to the epidemic of multiple pregnancies, did not arise ex vacuo. Women nowadays are able to rely on efficient modern fertility treatment when deciding on postponing childbirth. Advanced maternal age, by itself an established risk for natural multiples, is thus a significant risk factor for age-related reduced fecundity and for the increased need for fertility treatment. The early diagnosis of chorionicity does not require high-tech imaging and is of utmost clinical importance. The changes in women’s role in Western societies witnessed after World War II were facilitated by effective contraception, allowing ample time to achieve education and a career.