Fetal gender prediction based on placental location throughout first trimester transabdominal ultrasound

Background: Awareness of fetal gender at primary stages of pregnancy is very important. Fetal sex determination can reveal pressing information regarding fetal health. One of the methods of determining gender in the first trimester is according to the location of placenta. . This study investigated the accuracy and sensitivity of this method with trans-abdominal ultrasound in determining the sex of the fetus in the first trimester of pregnancy. Materials and methods: In this analytic– cross sectional study, 192 pregnant women who were visited by obstetrical clinics in Rajaii hospital, Tonekabon, Iran in 2019 were chosen by convenient sampling method. Trans-abdominal ultrasound was performed among them. Inclusion criteria were pregnant women who were in their 7th-11th weeks of pregnancy and exclusion criteria were multiple pregnancies, abortion and reluctance to participate in the study.  The fetal gender was predicted based on the location of the placenta (right, left, anterior, posterior). The results were compared with the actual sex of the fetus after birth. SPSS- statistical software version 21 was used for statistical analysis. P-value<0.05 was considered as significant level. Results: Out of 192 studied fetuses, 90 were female infants (46.9%) and 102 were male (53.1%). In 72% of the cases with placenta located on the right side, the fetus was male and in 70% of  the cases with placenta located on the left side, the fetus was female (P<0.05). The gender determination method accuracy in this study was 71.3% and the sensitivity for male and female sex determination was measured respectively 74.5% and 67.7%. Conclusion: According to the results, right and left positions of the placenta had significant relation with fetal gender. More conducted research with larger sample size as well as more detailed investigations about placental location is strongly urged.