Outcome of singleton preterm small for gestational age infants born to mothers with pregnancy-induced hypertension. A population-based study

Background: Pregnancy-induced hypertension (PIH) has been associated with a decreased risk of infant mortality in small for gestational age (SGA) preterm infants. Objective: To evaluate the influence of PIH on mortality and major neonatal morbidities in singleton preterm SGA infants, in the presence and absence of acute pregnancy complications. Methods: Population-based observational study of singleton SGA infants, born at 24 to 32 weeks gestation in the period 1995-2010 (n = 2139). Multivariable logistic regression analyses were used to assess the independent effect of PIH on mortality and neonatal morbidities. Acute pregnancy complications comprised premature labor, premature rupture of membranes >6 h, antepartum hemorrhage and clinical chorioamnionitis. Results: In the absence of pregnancy complications, the odds ratio (95% confidence interval) for mortality (0.77; 0.50-1.16), survival without severe neurological morbidity (1.14; 0.79-1.65) and survival without bronchopulmonary dysplasia (BPD) (0.85; 0.59-1.21) were similar in the PIH versus no-PIH groups. In the presence of pregnancy complications, mortality (0.76; 0.40-1.44), survival without severe neurological morbidity (1.16; 0.64-2.12) and survival without BPD (1.04; 0.58-1.86) were also similar in the PIH versus no-PIH groups. Conclusions: PIH was not associated with improved outcome in preterm SGA infants, both in the presence and absence of acute pregnancy complications.