Does Fetal Gender Really Affects Neonatal Birth Weight and Gestational Age at Birth? A Prospective Cohort Study

OBJECTIVE: The objective of this study was to understand the impact of fetal gender on neonatal birth weight for the gestational age at the time of birth. Only neonates with a gestational age of 28 weeks or more than 28 weeks were included in the study. METHODS: This prospective study was conducted within the Obstetrics and Gynecology Department of a rural tertiary center in Northern India. The study was conducted after ethical clearance and informed consent from participants who fulfilled the inclusion criteria. Data collection included neonatal gender, birth weight, Apgar scores, and gestational age. Neonates were delivered vaginally or by cesarean section at 28 or more weeks of gestation. Statistical analysis was done using version SPSS-22 software. RESULTS: Of 2,997 live fetuses, 1,574 (52.5%) were male, 1,421 (47.4%) were female, and 2 (0.07%) had ambiguous genitalia. Mean, standard deviation (SD) for male neonate's birth weight was 2.79 +/- 0.503 kg (95% confidence interval [CI]: 2.76-2.81), for females 2.67 +/- 0.485 kg (95% CI: 2.64-2.69) respectively (p =.000). Males had lower Apgar scores at 1 and 5 minutes of age compared to females (7.06 +/- 0.859, 8.83 +/- 0.838 vs. 7.12 +/- 0.645, 8.88 +/- 0.612). There were no significant difference between fetal gender and gestational age at birth (18% females were preterm vs. 15.4% males, 81.8% females were term vs. 84.2% males, 0.1% females post-term vs. 0.4% males; p =.079). CONCLUSION: Fetal gender was related to birth weight. Male neonates had a higher birth weight, but lower Apgar scores than female neonates. Fetal gender was not correlated with gestational age at the time of birth.