Effect of Maternal Hypertension on Neonatal Neutropenia and Risk of Nosocomial Infection

Abstract

Neonatal neutropenia occurs in ∼50% of newborns delivered by women with pregnancy-induced hypertension. It is thought to be transient, independent of birth weight and gestational age, and unassociated with significant risks, including infection. It recently was suggested that neonatal neutropenia occurs primarily in smaller, younger neonates, is related to the severity of pregnancy-induced hypertension, and importantly, may be associated with an increased risk for nosocomial infection. We examined these points in a large inborn population in consecutive years, performing retrospective (n = 110, 1989) and prospective (n = 151, 1990) studies in low birth weight (≤2200 g) neonates delivered by women with pregnancy-induced hypertension. Overall, 40% to 50% of neonates studied developed neonatal neutropenia, and they were younger and smaller (P < .01) than non-neutropenic neonates. In the prospective study, neutropenic neonates were more likely to have mothers with severe pregnancy-induced hypertension (P < .001), and the incidence of neonatal neutropenia was primarily among neonates <30 weeks of gestation and <1500 g birth weight, ∼80% vs 35% to 45% in older, larger neonates or infants (P < .001). Although nosocomial infection occurred more frequently among the group of neutropenic neonates in the prospective study (P < .02), the incidence was similar to that in matched non-neutropenic controls delivered of normotensive women. Thrombocytopenia (<100 000/mm3) was not more frequent in neutropenic neonates. Although neonatal neutropenia occurs in 40% to 50% of low birth weight neonates from pregnancies complicated by pregnancy-induced hypertension, this primarily reflects an incidence of 80% among neonates <30 weeks gestation. There is no apparent increased risk for development of nosocomial infection or thrombocytopenia.