Association between maternal Toxoplasma gondii IgG seropositivity and sex ratio at birth.

Toxoplasmosis has a wide range effects on the health, immunity, behavior, and prenatal and postnatal outcomes of the infected host. It can change hormones and even the birth sex ratio. This study was conducted with the aim of investigating the association between maternal Toxoplasma gondii IgG seropositivity and sex ratio at birth. In this prospective case-control study, 244 pregnant women including 54 pregnant women with IgG T. gondii antibodies as the case group and 190 pregnant women without IgG T. gondii antibodies as the control group were studied. All pregnant women was followed until delivery. Information about the neonate's sex was recorded. The relationship between the presence of T. gondii antibody and the birth sex ratio was obtained by the Kendall correlation test and the odds ratio was calculated. The sex ratio was 0.79 in negative toxoplasma antibody mothers while it was 1.0 in positive toxoplasma antibody mothers. This increase was not significant. The odds ratio (OR) was obtained 1.253 (p = 0.48). Our study showed that the presence of T. gondii antibody in the maternal serum might increase the birth sex ratio (XY birth). Considering to limited studies on human and contradictory results, more studies with sufficient sample and measuring physiological and biochemical markers is recommened.