Study Population and Design
This was a single center, prospective, observational cohort study (NCT02639676). Potential study participants were recruited from 3 local hospitals in Indianapolis, IN USA. Inclusion criteria for the study cohort included a clinical diagnosis of Pre-E (using definitions contained in the American College of Obstetrcis and Gynecology Task Force on Hypertension in Pregnancy 2013 report) with anticipated delivery between 26-40 weeks GA determined by best obstetrical dating (last menstrual period confirmed by ultrasound) [14]. We also recruited a comparison cohort of infants born from normotensive pregnant women with anticipated delivery between 26-40 weeks GA determined by best obstetrical dating. Exclusion criteria included multiple gestation pregnancy, prenatally identified fetal cardiopulmonary defects, known fetal chromosomal disorders, women with diabetes mellitus, and women with chronic or gestational hypertension. Prematurity was not an exclusion criterion for either cohort, and the final cohorts were comprised of term and preterm infants. Prior to initiation of this study, we received approval from the Indiana University Institutional Review Board. The mothers of infant study participants all provided written informed consent.
We used the electronic medical record to obtain maternal clinical information, such as maternal medications (e.g. antenatal steroids, magnesium sulfate, other anti-hypertensive therapies), tobacco use, and family history of asthma. We also obtained neonatal clinical information such as birth weight and length, gestational age at birth, sex, race, and need for interventions such as exogenous surfactant therapy, positive pressure ventilation, and supplement oxygen use.
Following discharge from the hospital, we performed monthly telephone surveys to track episodes of wheezing, respiratory medication use (e.g. inhaled bronchodilators and inhaled corticosteroids), and hospitalizations for respiratory related illness.