Associations of Preeclampsia with Expiratory Airflows in School-Age Children Born Either at

Abstract

To assess whether preeclampsia was associated with expiratory airflow at school-age in children born either extremely preterm (<28weeks of gestation) or extremely low birthweight (ELBW; <1000g birth weight). Participants comprised 3 cohorts of children born extremely preterm/ELBW in the state of Victoria, Australia, in 1991-1992, 1997, or 2005. Expiratory airflows were measured at age 8years, and results converted to z scores. Data were compared between those exposed to preeclampsia with those unexposed to preeclampsia; analyses were then adjusted for confounding perinatal variables. Analyses were repeated within subgroups of extremely preterm only and ELBW only. Respiratory data were available for 544 of 717 (76%) survivors, of whom 95 (17%) had been exposed to preeclampsia. On univariable analysis, those exposed to preeclampsia had better z scores for flows for the forced expired volume in 1second (zFEV1) (mean difference 0.29, 95% CI 0.04-0.53; P=.022) and zFEV1/forced vital capacity (mean difference 0.33, 95% CI 0.04-0.61; P=.025); the difference persisted for zFEV1 after adjustment for confounding perinatal variables. Analyses confined to those born extremely preterm revealed little evidence for associations between preeclampsia and airflow. In analyses confined to those born ELBW, preeclampsia was associated with better zFEV1, which persisted after adjustment (mean difference 0.33, 95% CI 0.04-0.63; P=.025). Exposure to maternal preeclampsia was not associated with worse expiratory airflow in children born extremely preterm/ELBW; in fact, some airflows were better.