Recurrence of hypertensive disorders of pregnancy: results from a nationwide prospective cohort study (CONCEPTION).

Objective: To assess the risk of gestational hypertension (GH) and pre-eclampsia (PE) during a second pregnancy after occurrence during a first pregnancy.

Design: Prospective cohort study.

Setting: CONCEPTION is a French nationwide cohort study that used data from the National Health Data System (SNDS) database.

Methods: We included all women who gave birth for the first time in France in 2010-2018 and who subsequently gave birth. We identified GH and PE through hospital diagnoses and the dispensing of anti-hypertensive drugs. The incidence rate ratios (IRR) of all hypertensive disorder of pregnancy (HDP) during the second pregnancy were estimated using Poisson models adjusted for confounding.

Main Outcome Measures: Incidence rate ratios of HDP during the second pregnancy.

Results: Of the 2 829 274 women included, 238 506 (8.4%) were diagnosed with HDP during their first pregnancy. In women with GH during their first pregnancy, 11.3% (IRR 4.5, 95% confidence interval [CI] 4.4-4.7) and 3.4% (IRR 5.0, 95% CI 4.8-5.3) developed GH and PE during their second pregnancy, respectively. In women with PE during their first pregnancy, 7.4% (IRR 2.6, 95% CI 2.5-2.7) and 14.7% (IRR 14.3, 95% CI 13.6-15.0) developed GH and PE during their second pregnancy, respectively. The more severe and earlier the PE during the first pregnancy, the stronger the likelihood of having PE during the second pregnancy. Maternal age, social deprivation, obesity, diabetes and chronic hypertension were all associated with PE recurrence.

Conclusion: These results can guide policymaking that focuses on improving counselling for women who wish to become pregnant more than once, by identifying those who would benefit more from tailored management of modifiable risk factors, and heightened surveillance during post-first pregnancies.