Aim: The aim of this study is to determine the relationship between placental /chorionic villi laterality, fetal genders, pyelectasis, and other abnormalities.
Material and Method: This is a multi-center prospective cohort blind study carried by 3 sonographers including the author for 5376 pregnant women that underwent ultrasonography from 1997 to 2007. Trans-vaginal sonograms were performed in 22% of the patients at 6 weeks gestation, and Trans-abdominal sonograms were used at 18-20 weeks gestation for varieties of reason.
Result: Dramatic differences were detected in chorionic villi / placental location according to gender. 97.2% of the male fetuses had a chorionic villi/placenta location on the right side of the uterus whereas, 2.4% had a chorionic villi/placenta location to the left of the uterus. On the other hand 97.5% of female fetuses had a chorionic villi/placenta location to the left of the uterus whereas, 2.7% had their chorionic villi/placenta location to the right side of the uterus.127 cases were found to involve bicornuate uteri with single foetuses, most male fetuses were located in the right horn of the uterus and showed right placental laterality (70%). Most female fetuses 59% on the other hand, were located in the left horn and showed left laterality (59). CI was > 95%, P value <0.001 is very significant
Conclusion: This study is relibale of predicting the fetal gender up to 97% for bothe sexes.