Risks of cause-specific mortality in offspring of pregnancies complicated by hypertensive disease of pregnancy

Abstract

Background: Fetal environment has a substantial influence on an individual's health throughout their life course. Animal models of hypertensive disease of pregnancy have demonstrated adverse health outcomes among offspring exposed to hypertensive disease of pregnancy in utero. Although there are numerous descriptions of the neonatal, infant, and pediatric outcomes of human offspring affected by hypertensive disease of pregnancy, there are few data in US populations on later life outcomes, including mortality.

Objective: To assess risk for early mortality among offspring of pregnancies complicated by hypertensive disease of pregnancy.

Study design: This is a retrospective cohort study of offspring born to women with singleton or twin pregnancies between 1947 and 1967 with birth certificate information in the Utah Population Database. We identified offspring from delivery diagnoses of gestational hypertension, preeclampsia, or eclampsia. Offspring from these pregnancies (exposed) were matched to offspring of pregnancies without hypertensive disease of pregnancy (unexposed) by maternal age at delivery, birth year, sex, and multiple gestation. We also identified unexposed siblings of exposed offspring for a separate sibling analysis. Mortality follow-up of all offspring continued through 2016, at which time they would have been 49-69 years old. Adjusted hazard ratios for cause-specific mortality comparing exposed with unexposed offspring were estimated using Cox proportional hazard models.

Results: We compared mortality risks for 4050 exposed offspring and 6989 matched unexposed offspring from the general population and 7496 unexposed siblings. Mortality risks due to metabolic, respiratory, digestive, nervous, and external causes of death did not differ between exposed and unexposed groups. Mortality risks from cardiovascular disease were greater in exposed offspring compared with unexposed offspring (adjusted hazard ratio, 1.57; 95% confidence interval, 1.16-2.12). In sex-specific models among the general population, cardiovascular disease mortality was significantly associated with exposure among male patients (adjusted hazard ratio, 1.92; 95% confidence interval, 1.27-2.88) but not among female patients (adjusted hazard ratio, 0.97; 95% confidence interval, 0.81-1.94). An interaction between hypertensive disease of pregnancy exposure and birth order on cardiovascular disease mortality was significant (P=.047), suggesting that the effect of hypertensive disease of pregnancy on cardiovascular disease mortality increased with higher birth order. Among siblings, the association between hypertensive disease of pregnancy exposure and cardiovascular disease mortality was not significant (adjusted hazard ratio, 1.39; 95% confidence interval, 0.99-1.95), and this was also true for sex-specific analyses of males (adjusted hazard ratio, 1.26; 95% confidence interval, 0.81-1.94) and females (adjusted hazard ratio, 1.71; 95% confidence interval, 0.96-3.04). As in the general population, there was a significant interaction between hypertensive disease of pregnancy exposure and birth order on cardiovascular disease mortality (P=.011).

Conclusion: In a US population, overall mortality risks are greater for offspring of pregnancies complicated by hypertensive disease of pregnancy compared with unexposed offspring. Among siblings, there was not a significant association between hypertensive disease of pregnancy exposure and cardiovascular disease mortality.

Keywords: Barker hypothesis; cardiovascular disease; fetal programming; pregnancy as a window to future health.