Extremely preterm birth affects boys more and socio-economic and neonatal variables pose sex-specific risks

Area of Science:

• Neonatalogy
• Developmental Pediatrics
• Perinatal Medicine

Background:

• Early identification of extremely preterm (EPT) children is crucial for improving long-term outcomes.
• Understanding sex-specific developmental trajectories in EPT infants is essential for targeted interventions.

Purpose of the Study:

• To investigate sex differences in developmental outcomes at two and a half years of age in EPT children.
• To identify sex-specific predictors of developmental outcomes in EPT infants.

Main Methods:

• Assessed 217 boys and 181 girls born before 27-week gestation using the Bayley Scales of Infant and Toddler Development, third edition (Bayley-III).
• Analyzed sex-specific differences and utilized regression models to identify predictors (socio-economic, birth, neonatal factors) separately for boys and girls.

Main Results:

• Girls demonstrated significantly higher scores than boys across all Bayley-III indices.
• Brain injury, prolonged ventilator support, and foreign-born mothers predicted lower scores in both sexes.
• Breast milk feeding at discharge predicted higher scores; severe retinopathy of prematurity was the strongest predictor for cognitive/language deficits in boys, while high parental education predicted better cognitive/language scores in girls. Severe bronchopulmonary dysplasia was the strongest motor deficit predictor in girls.

Conclusions:

• Extreme prematurity appears to have a more significant impact on boys' development compared to girls.
• While socio-economic and neonatal factors present similar risks/protections for both sexes, certain variables exhibit sex-specific effects.
• Recognizing these sex-specific risk factors is vital for developing tailored treatment and follow-up guidelines for EPT children.