Pregnancy complications linked to decreased longevity

Women who experience pregnancy complications appear to have increased mortality about 50 years thereafter, according to data from the Collaborative Perinatal Project.

The Collaborative Perinatal Project was a large prospective cohort study that included 48,197 pregnant participants from 12 clinical centres across the US. The vital status of all participants was monitored through 2016 with linkage to the National Death Index and Social Security Death Master File.

All-cause and cause-specific mortality were estimated in relation to the incidence of pregnancy complications, including preterm delivery, hypertensive disorders of pregnancy, and gestational diabetes/impaired glucose tolerance (GDM/IGT).

The analysis included 46,551 participants (mean age 24.5 years, 45 percent Black). The median time between the index pregnancy and death/censoring was 52 years.

Overall, 6,753 participants (15 percent) had preterm delivery, 2,155 (5 percent) had hypertensive disorders of pregnancy, and 540 (1 percent) had GDM/IGT. The incidence of preterm delivery was notably higher among Black than White participants (20 percent vs 10 percent). Furthermore, more Black than White participants died during the follow-up (41 percent vs 37 percent).

The risk of all-cause mortality was high among participants with preterm spontaneous labour (adjusted hazard ratio [aHR], 1.07, 95 percent confidence interval [CI], 1.03–1.1), those with preterm premature rupture of membranes (aHR, 1.23, 95 percent CI, 1.05–1.44), those with preterm induced labour (aHR, 1.31, 95 percent CI, 1.03–1.66), and those with preterm prelabour caesarean delivery (aHR, 2.09, 95 percent CI, 1.75–2.48) as compared with participants who had full-term delivery.

All-cause mortality was also elevated among participants with gestational hypertension (aHR, 1.09, 95 percent CI, 0.97–1.22), those with pre-eclampsia or eclampsia (aHR, 1.14, 95 percent CI, 0.99–1.32), and those with superimposed pre-eclampsia or eclampsia (aHR, 1.32, 95 percent CI, 1.20–1.46) than among participants with normotensive pregnancy.

Finally, participants with GDM/IGT had a higher risk of all-cause mortality compared with those who were normoglycemic (aHR, 1.14, 95 percent CI, 1.00–1.30).

The effect modification on all-cause mortality between Black and White participants was significant for preterm delivery (p=0.009) and hypertensive disorders of pregnancy (p=0.05) but not for GDM/IGT (p=0.92). Specifically, preterm induced labour was associated with greater mortality risk among Black than White participants (aHR, 1.64 vs 1.29), whereas preterm prelabour caesarean delivery was linked to higher mortality risk among Whites vs Blacks (aHR, 2.34 vs 1.40).