The relationship between Toxoplasma gondii infection in mothers and neonate’s gender

Abstract

Background

The secondary sex ratio can be affected by various factors such as stress, immunosuppression, and age of parents in addition to mother infectious disease (Maternal infections). Toxoplasmosis is one of the critical maternal parasitic infections during pregnancy. Besides the complications of the acute form of the disease, hormonal shifts, and even alterations in the secondary sex ratio can be induced by the manipulative activity of the chronic form of the disease. Therefore, this study aimed to evaluate the correlation between Toxoplasma gondii infection in mothers and neonate’s gender.

Methods

In this case-control study, 137 seropositive mothers to Anti-Toxoplasma IgG(case) was compared to 137 age-matched subject Toxoplasma-seronegative mothers(control) in terms of their neonate’s gender. These individuals were randomly selected based on exclusions and inclusions criteria of the study from among 2014 mothers who had been tested for Toxoplasma infection during pregnancy from 2015 to 2018 in Shiraz, Iran.

Results

From a total of 2014 studied pregnant mothers, 326 (16.2%) mothers were seropositive to anti-Toxoplasma IgG, and 1688 (83.8%) were negative for IgG. It was found that the numbers of female and male neonates were 136 (45.48%) and 163 (54.51%) in the control group whereas, they were 165 (49.84%) and 166 (50.15%) in the case group, respectively. The sex ratio was 1.006:1 in Toxoplasma-seropositive and 1.2:1 in Toxoplasma-seronegative mothers. The number of male and females offsprings indicated a significant difference in Toxoplasma-seronegative mothers (54.5%, p = .015). Moreover, comparing the number of males and females between the two randomly selected groups showed that female gender is significantly more than male gender in seropositive mothers to Toxoplasma (54.8%, p = .014), which means that of 301 females, 165 offspring were born to seropositive mothers. No significant difference was observed for the sex ratio of aborted fetuses between groups. However, in the Toxoplasma-seropositive group, the sex ratio of aborted fetuses showed that the aborted male fetuses were significantly higher in number. (31 male vs 13 female, p < .001).

Conclusion

Comprehensively, a significant relationship was found between chronic Toxoplasma infection and secondary sex ratio. However, it is suggested that this relationship be investigated in further studies as well as an animal study.

Keywords:

• Toxoplasma gondii
• mothers
• neonate
• gender
• sex ratio

Acknowledgements

This study was undertaken as an MD degree thesis for Fatemeh Zarei. The author’s thanks from hospitals and clinics for their solidarity.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethical approval

The current study was approved by the Ethical Committee of Shiraz University of Medical Sciences, Shiraz, Iran (Ethical code: IR.SUMS.REC.1398.224). Informed written consent was obtained from all participants before being involved in the study. All participants signed an informed consent and received a complete copy of the signed consent form.

Data availability statement

The dataset used and/or analyzed during the current study is available from the corresponding author upon reasonable request.

Additional information

Funding

The study was financially supported by the office of vice-chancellor for research of Shiraz University of Medical Sciences [Grant No. 19664].