Outcomes measures
The primary outcome was perinatal mortality, defined as a composite of
stillbirth (fetal deaths at 20 weeks’ gestation or greater), early
neonatal death (deaths within 0–6 days of life), and late neonatal
death (deaths between 7–28 days of life). Since timely obstetrical
interventions may prevent stillbirth, but could lead to neonatal death,
the composite was intended to capture perinatal mortalities that could
be attributed to exposure to chronic hypertension. We also quantified
the impact of chronic hypertension on stillbirth, as well as early and
late neonatal deaths, as secondary outcomes.