P-179: The Role of Fetal Sex on Preterm Labor

Background: Preterm labor is a major problem in obstetric practice. Rates of preterm birth vary between different populations and ethnic groups. In maternal fetal medicine, gender differences in outcome are often observed. Epidemiologic studies have suggested that the incidence of preterm birth is also higher in pregnancies carrying a male fetus. The purpose of this article is to review the evidence that the sex of the fetus may has a role in increasing preterm labor risk and need to be considered amongst the known compounding risk factors for threat of preterm labor. Materials and Methods: A population-based study comparing all singleton 28 - 36 weeks gestational age deliveries that between 2010 and 2012 was performed. We compared pregnancies with male vs. female fetuses. Patients with a previous cesarean section, preterm labor and vaginal bacterial vaginosis infection were excluded from the study. Statistical analysis was performed with the SPSS software and differences were considered significant at p values < 0.05. Results: During the study period 2450 deliveries were occurred in our hospital. Ten percent of births were less than 36 weeks gestational age. Male infants had a greater incidence of preterm birth. The male/female ratios were 1.71. Rate of neonatal mortality was also consistently higher in male offspring (30 vs. 21%). Conclusion: These results showed greater male susceptibility to preterm labor. Rate of mortality was also consistently higher in male offspring.