Previous studies suggest postnatal blood pressure in preterm infants to be decreased by
chorioamnionitis and increased by antenatal
steroids (AS). We examined the adjusted effects of both antenatal modulators on postnatal blood pressure (BP), with separate effects reported for histologic
chorioamnionitis with or without fetal involvement and timing of AS. General characteristics, BP, and heart rate values during the first 72 h after birth were obtained from 271 infants with gestational age <or=32.0 wk. In unadjusted analyses,
chorioamnionitis was associated with lower BP, most prominently so in infants with fetal involvement, without an effect on
hypotension incidence. AS increased BP and decreased the incidence of
hypotension when administered within 7 d before birth. In a multivariable mixed model analysis, the AS effect remained significant, whereas
chorioamnionitis was not independently predictive of postnatal BP. Other variables associated with increased postnatal BP were gestational age and umbilical artery pH, whereas
hemolysis, elevated liver
enzymes, low platelets syndrome was associated with decreased BP. In conclusion, AS seem to increase postnatal BP and decrease
hypotension in preterm infants when given within 7 d before birth. Conversely,
chorioamnionitis did not significantly affect postnatal BP after multivariable adjustment.