Gender and birth trauma in full-term infants.

OBJECTIVE

To investigate the association between gender and birth trauma in full-term infants.

METHODS

A retrospective, cohort, case-control study was conducted. All singleton full-term neonates born in 1986-2009 and diagnosed with birth trauma (ICD9-CM codes 767.0-767.9) were identified from the hospital's computerized birth-discharge records. The study group was matched in a 2:1 ration with neonates delivered immediately after each index case of neonatal trauma.

RESULTS

Of the 118, 280 singleton full-term infants delivered during the study period, 2876 (24/1000) experienced birth trauma. The most frequent birth traumas were scalp injury (63.9%) and clavicle fracture (32.1%). The overall risk of birth trauma was unrelated to fetal gender. However, fetal male gender was a significant and independent risk factor for scalp injury (OR=1.31, 95%-CI 1.15-1.49), and female fetal gender was a significant and independent risk factor for clavicle fracture (OR=1.27, 95%-CI 1.09-1.49). The significance of these associations persisted even after adjustment for potential confounders including mode of delivery, gestational age, neonatal length, timing of delivery, head circumference, parity, and birth weight.

CONCLUSION

Fetal gender appears to be a predisposing risk factor for specific types of birth trauma. Further studies are needed to investigate the reasons for this observation.