Die Tendenz zu Zwillingsgeburten

Abstract

1. The probability that a mother who has already given birth to twins will repeat the twin birth has been shown to be 3.63 ± 0.24%.a) The increase in the frequency of binovular twin births of 4,55 ± 0,90% is statistically significant.b) The increase in the frequency of monovular twin births of 1.43 ± 0,90% is not statistically sure in this data because of the relatively high standard error.2. Althrough it cannot by proved statistically, there is some indication that, amongst the later births to women who have initially given birth to binovular twins, there is an increase in the frequency of monovular twins, and vice-versa.3. Hormonal disturbances, such as a slow secretion of folliculin which would prevent ovulation, may be the cause of binovular twinning. Mon ovular twinning is probably due to an inherent tendency of the egg to divide. It is pos sible that if this tendency manifests itself before the reduction division and two separate eggs are formed binovular twinning may result. With this hypothesis is mind, an attempt has been made to discover some correlation between monovular and binovular twinning.