بررسی اثر گروه‌های خونی والدین بر محل لانه‌گزینی جنین و نسبت جنسی ثانویه در کودکان متولد شده در بیمارستان الزهرای میاندوآب

ABackground & Aims: The aim of this study was to investigate the relationship between parents' ABO and Rh blood groups on the secondary sex ratio and location of the placenta (as a mediator between blood groups and sex ratio), due to the existence of evidence that the implantation site and embryo gender are related.   Materials & Methods: 200 neonates born during 2014 to 2016 at Al-Zahra Hospital of Miandoab were collected through referral to mothers' case or by completing the questionnaire by telephone interview and analyzed in a multiple logistic regression model.   Results: In numerical view, the highest ratio of secondary sex ratio was observed in infants born to mothers with AB type blood group (1.750) and the lowest was in infants born to mothers with B (0.720) and O (0.718) blood groups (p> 0.05). Mothers with Rh- had a greater bias in having a girl, while mothers with Rh+ showed normal distribution in their children sex ratio (p<0.05). In families with Rh- mother and Rh+ father had more girls 6 times than normal sex ratio (p< 0.05). In fathers with AB blood group, the odds ratio of anterior placenta by their children in the mother's uterus was more than 4 times that of other ABO blood groups (p<0.05). There was no significant association between maternal and paternal Rh blood groups with the location of their children’s placental (p> 0.05).   Conclusion: To confirm the hypothesis that the paternal or maternal ABO blood-type affects the secondary sex ratio through implantation of the fetus (location of the placenta), future research is required in different populations with larger sample sizes.