Hypertensive disorders of pregnancy and onset of chronic hypertension in France: the nationwide CONCEPTION study

Hypertensive disorders of pregnancy (HDP) are a leading cause of maternal and foetal morbidity and mortality. We aimed to estimate the impact of HDP on the onset of chronic hypertension in primiparous women in the first years following childbirth.This nationwide cohort study used data from the French National Health Data System (SNDS). All eligible primiparous women without pre-existing chronic hypertension who delivered between 2010 and 2018 were included. Women were followed up from six weeks post-partum until onset of hypertension, a cardiovascular event, death, or the study end date (31 December 2018). The main outcome was a diagnosis of chronic hypertension. We used Cox models to estimate hazard ratios (HRs) of chronic hypertension for all types of HDP. Overall, 2 663 573 women were included with a mean follow-up time of 3.0 years. Among them, 180 063 (6.73%) had an HDP. Specifically 66 260 (2.16%) had pre-eclampsia (PE) and 113 803 (4.27%) had gestational hypertension (GH). Compared with women who had no HDP, the fully adjusted HRs of chronic hypertension were 6.03 [95% confidence interval (CI) 5.89-6.17] for GH, 8.10 (95% CI 7.88-8.33) for PE (all sorts), 12.95 (95% CI 12.29-13.65) for early PE, 9.90 (95% CI 9.53-10.28) for severe PE, and 13.17 (95% CI 12.74-13.60) for PE following GH. Hypertensive disorders of pregnancy exposure duration was an additional risk factor of chronic hypertension for all PE subgroups. Women with HDP consulted a general practitioner or cardiologist more frequently and earlier.Hypertensive disorders of pregnancy exposure greatly increased the risk of chronic hypertension in the first years following delivery.