Background It’s generally accepted that male Very Low Birth Weight (VLBW)/Very Low Gestational Age (VLGA) infants have a higher neonatal mortality rate (NMR), and this has been questioned recently (Arch Dis Child Fetal-Neonatal Ed. 2009; 94:F140–3).
Aim To determine if male gender has an adverse effect on NMR and early morbidity in VLBW/VLGA infants.
Methods Perinatal risk/protective factors, early neonatal complications and NMR were compared between male and female VLBW/VLGA infants admitted from 2006 to 2010 in 174 EuroNeoNet NICUs from 17 European countries (N=28,035). Independent comparisons using non-parametric tests and logistic regression models were performed to predict adjusted NMR. Crude and adjusted odds ratios (OR) were used to determine perinatal and early neonatal associations.
Results Male infants (52.3%) had a lower GA and higher BW than females. Crude NMR was higher in males (14 vs. 11.6%; OR=1.24 95%CI: (1.16–1.33)) as were most perinatal and early neonatal risk factors (vaginal delivery, low Apgar scores, resuscitation, RDS and need for surfactant therapy and early-onset sepsis), as well as major adverse neonatal outcomes (pneumothorax, late-onset sepsis, BPD, IVH3–4, PVL and ROP3–4). These differences in NMR and complications remained after adjusting for GA and/or BW alone and by perinatal differentiating factors for gender: BW, GA, 1-min Apgar score and multiple pregnancy (NM: OR=1.32 95%CI: 1.21–1.44).
Conclusion Male infants of VLBW/VLGA have a higher adjusted NMR and an increased rate of adverse neonatal outcomes.
Acknowledgements We thank patients and NICUs participating NICU’s. EuroNeoNet is supported by the DGSANCO (EuroNeoStat project No 2008/1311).