Multiple Pregnancy in Humans

a pregnancy in which several fetuses develop simultaneously. The occurrence of multiple births is relatively rare: twins occur once in 80 births, triplets once in 6,400 births, quadruplets once in 512,000 births, and quintuplets once in 40,960,000 births. Sextuplet and septuplet births have been recorded. It is conjectured that the causes of multiple pregnancy may be the simultaneous fertilization of two eggs (double-ovum twins); the division of one fertilized egg into two or more parts, each of which subsequently develops independently; and the occurrence of two nuclei in one fertilized egg, from which develop after division two independent embryos.

Multiple pregnancies occur most often in women whose family or whose husband’s family has a history of multiple births. There is record of a woman who, in the course of 11 pregnancies, gave birth to three sets of twins, six sets of triplets, and two set of quadruplets (32 children in all). Her husband was a twin and she was a quadruplet.

Women who have a multiple pregnancy are placed under special observation by their clinics. In the event of any complications, they are hospitalized for examination and treatment. In complication-free multiple pregnancies, the women are hospitalized two weeks before the expected birth. Premature birth, premature bursting of the amnion of the first fetus, primary and secondary uterine inertia, and improper positioning of the fetuses often occur in multiple pregnancies. After childbirth, medicinal preparations that contract the uterus are used to prevent hemorrhaging.