Newborn's condition at birth does not depend on maternal sexual strategy—evidence against the “hunting for good genes” hypothesis

Abstract

Neonatal weight and health depend on many epigenetic and environmental factors and also on a child's genes as inherited from the mother and the father. The "Hunting for Good Genes" (HfGG) hypothesis claims that women pursue short-term mating strategies in order to obtain good genes for their progeny. If this is true, one should expect that in comparison to children born in long-term relationships (LR), children born in short-term relationships (SR) should have a larger neonatal size and be healthier. To test the HfGG hypothesis, and whether sexual strategy influences neonatal parameters, we used an on-line questionnaire aimed at mothers. Totally, 1,558 women took part in this study, and among them 130 conceived their first-born child in a short-term relationship (SR mothers) and 1,428 in a long-term relationship (LR mothers). There was no difference between those two groups of children in terms of birth weight and Apgar score. Although we found no difference in the occurrence of genetic diseases and birth defects between SR and LR boys, the girls born by LR mothers were healthier than those born by SR mothers. We also did not find any difference in the sex ratio of the children born to SR and LR mothers. The results of our study do not support the "Hunting for Good Genes" hypothesis for the first born child. In the contemporary western society of the study, women do not seem to derive genetic benefits expressed as child condition at birth from short-term relationships.