Cesarean section and rate of subsequent explained or unexplained stillbirth.

Cohort 1982–1996 (n = 427,498 women); cohort 1997–2010 (n = 405,498 women).aNumber of events of the outcome of interest for each mode of delivery in parentheses.bModel 1: adjusted for maternal age; maternal origin; previous stillbirth, miscarriage, or ectopic pregnancy; mother's marital status; birth year; and measures of socio-economic status including mother's educational attainment and mother's and father's gross income.cModel 2: adjusted for Model 1 plus medical complications in the first live birth including delivery type (singleton versus twins or more), diabetes, gestational diabetes, placental abruption, placenta praevia, and hypertensive disorders (including eclampsia and preeclampsia).dModel 3: adjusted for Model 2 plus gestational age and birth weight.eExplained and unexplained stillbirth refer to a cause-specific competing risks for each type of stillbirth. Data for the causes of stillbirth were available from 1982–1996 only (cohort size = 427,498).*Where the number of events was less than ten for maternally requested cesarean, these were combined with the elective cesarean group for analyses.