Relationship Between Fetal Sex and Nausea and Vomiting During Pregnancy

Nausea and vomiting of pregnancy (NVP) affects approximately 80% of pregnant women. Its cause remains largely undetermined. The aim of this study was to assess the effect of fetal sex on tendency of NVP. A population-based study comparing all singleton pregnancies of patients carrying male and female fetuses was performed in Shahid Sadoughi hospital, Yazd, Iran from May 2010 to April 2011. Data were obtained from maternal self-reported information and prenatal care records during the first visit (<16 weeks of gestation). We get the offspring sex ratio of all births and compared in mother with history of NVP and none. Statistical analysis was performed with the SPSS software and differences were considered significant at P values < 0.05. Results revealed that during the study period 2450 deliveries were occurred in our hospital. There were no significant differences between the groups regarding maternal age, gestational age, gravida, education and mother employment. There were 1241 (50.6%) deliveries of male and 1209 (49.4%) deliveries of female gender. NVP was reported by 1862 women (76%) and approximately half of which had been vomiting. The rate of NVP was higher in women with male fetuses than female fetuses (79.5% vs72.3%).. In conclusion, this study showed that women presenting with NVP are more likely to have a male fetus than female.