PREGNANCY-INDUCED HYPERTENSION AND REDUCED INTRAVENTRICULAR HEMORRHAGE IN PRETERM INFANTS

Increasing evidence suggests that the incidence of periventricular int raventricular hemorrhage (PV-IVH) is lower in infants born to mothers with pregnancy-induced hypertension (PIH). The mechanism or mechanisms accounting for this reduction remain unclear but may be related to PI H itself, medications used to treat the mother (e.g., magnesium sulfat e), or to obstetrical management. In this retrospective analysis, we d etermined the incidence of PV-IVH in singleton preterm infants weighin g less than 1,500 gm born to mothers with PIH who were also administer ed magnesium sulfate. Between January 1988 and December 1994, 254 sing leton infants born to mothers with PIH and 1,083 born to mothers witho ut PIH were studied. PV-IVH developed in 360 (26.9 %) of the 1,337 inf ants; 977 (74.1%) infants did not exhibit PV-IVH. The incidence of tot al as well as severe PV-IVH was lower in infants born to mothers with PIH than in those without PIH [i.e., 16% vs 30% (total) and 8.2% vs 14 .5% (severe), P <.001] with an odds ratio (OR) estimate of 0.43 [95% c onfidence interval (CI) 0.30, 0.61]. Infants born to mothers with PIH weighed more, (1,152 +/- 250 gm vs 1,058 +/- 283 gm, P <.001) and were more mature (30.1 +/- 2.9 vs 27.7 +/- 31 weeks, P <.001) than infants born to mothers without PIH. These infants were also less likely to b e exposed to labor (57 % vs 93%), to be delivered by cesarean section (81% vs 35%), and to require intubation (49% vs 58%), but more likely to exhibit respiratory distress syndrome (RDS) (47% vs 38%, P <.01). B y logistic regression analysis, after seven variables (i.e., PIH, gest ational age, and birthweight, both modeled as cubic polynomials; labor ; intubation; RDS; and race) were included in the analytic model, pin remained a significant predictor of IVH: P =.006, OR = 0.54 (95 % CI 0 .349, 0.847). These data indicate a significantly lower incidence of P V-IVH of approximately 50% in infants born to mothers with PIH as comp ared with the incidence in infants born to mothers without PIH, despit e their higher incidence of RDS. The reduction in PV-IVH may be direct ly related to the RID; however, the independent role of antenatal magn esium sulfate administration requires further study. (C) 1997 by Elsev ier Science Inc. All rights reserved.