Infant sex, obstetric risk factors, and 2-year neurodevelopmental outcome among preterm infants.
OBJECTIVE
To evaluate the effect of the interaction between fetal sex and obstetric variables on the risk of neurodevelopmental impairment among preterm infants.


METHODS
A cohort study of 394 male and 360 female surviving infants born at 24 to 33 completed weeks of gestational age. Neurological examination and cognitive assessment of the infants (Bayley Scales of Infant Development) were performed at 2 years corrected age.


RESULTS
Mean gestational age was 30.4 weeks (SD 2.4). Rates of mild and moderate-to-severe neurodevelopmental impairment were 14.6% (110/754) and 7% (53/754) respectively. In logistic analysis, male sex was associated with an increased risk of neurodevelopmental impairment (odds ratio 1.8, 95% confidence interval 1.21-2.68) compared with females. The excess risk of neurodevelopmental impairment associated with male sex was higher among preeclamptic than normotensive pregnancies (p for interaction=0.004), among infants who were either small for gestational age or delivered to a mother with preeclampsia (p for interaction=0.001) and in iatrogenic as opposed to spontaneous preterm birth or preterm premature rupture of membranes (p for interaction=0.035).


CONCLUSIONS
The excess risk of neurodevelopmental impairment associated with male sex among preterm infants is modulated by obstetric risk factors.
University of Pavia, Department of Obstetrics and Gynecology, IRCCS Fondazione Policlinico San Matteo, P le Golgi, 25, Pavia 27100, Italy. spinillo@smatteo.pv.it
Arsenio
A
Spinillo
Laura
L
Montanari
Barbara
B
Gardella
Marianna
M
Roccio
Mauro
M
Stronati
Elisa
E
Fazzi
D002657:Child Development; D002675:Child, Preschool; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000009:adverse effects / Q000145:classification*; D002658:Developmental Disabilities / Q000453:epidemiology* / Q000209:etiology; D004198:Disease Susceptibility; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007558:Italy / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D009422:Nervous System Diseases / Q000453:epidemiology* / Q000209:etiology; D011247:Pregnancy; D047928:Premature Birth; D012307:Risk Factors; D012737:Sex Factors