Abstract
Objective: Hormonal contraceptives were shown to affect female mate preferences, which might have impact on subsequent biological quality of the offspring. Specifically, a shift in preference towards Major Histocompatibility Complex (MHC)-similar partners in combined oral contraceptive (COC) users raises the possibility that women who use COCs during the critical period of mate choice may have lower reproductive outcomes.
MHC allele-sharing connected e.g. with higher rates of fetal loss and lower offspring birth weight, could, together with reduced levels of MHC-heterozygosity of offspring, have implications on child health. Here we provide the first evidence of this relationship.
Methods: Based on large international survey we compared responses from women who met biological fathers of their first child when using COCs (n = 661) with those who did not (n = 963). All fulfilled onlinequestionnaires including measures of reproductive potential of couples (e.g. the incidence of miscarriages, time spend on trying to conceive) and child health (e.g. mothers' assessment of her child heath between delivery and 1 year on the scale).
Between group differences were tested by Mann-Whitney U tests, as well as by subsequent GLM models to control for other potentially confounding variables. Results: In couples of OC users at the time of mate choice, the time to conception was longer (z = 2.307, p = 0.021).
However, we did not find significant difference in number of miscarriages, nor in the birth weight of children. As predicted, health of children during their first year of life was rated as lower within couples of OC users (GLM model: B = 0.146, P = 0.019).
Conclusion: Our results provides the very first evidence that widespread use of OCs could have negative epidemiological consequences regarding population health and reproductive potential of couples.