Adverse pregnancy and postpartum outcomes among women with chronic hypertension in France (2010–2018): The nationwide CONCEPTION study

Abstract

In France, 1.5% of primiparous women has a chronic hypertension (HT) before pregnancy. Its impact on fetal and maternal outcomes remains unclear. We aimed to estimate the impact of chronic hypertension on the onset of cardiovascular events during pregnancy and postpartum (PP). We identified every primiparous woman who gave birth in France between 2010 and 2018, using data from the French National Health Insurance Information System database. Chronic HT before pregnancy and maternal cardiovascular outcomes were identified by deliveries of anti-HT drugs and hospital diagnosis codes. Renin-angiotensin-blockers were considered strictly contra-indicated during the 2nd and 3rd trimesters of pregnancy. We used Poisson models to estimate incidence relative risk (IRR) of adverse pregnancy and PP outcomes among women with chronic HT. Overall, 2,825,529 women were included. Among them, 42,919 (1.5%) had chronic HT and 25,636 were treated during pregnancy (60% of chronic HT). Women with chronic HT were older and were more likely to smoke, to be socially deprived, to be obese, diabetic, and to have previous cardiovascular, venous or renal medical history. In fully-adjusted models, the IRR [95% confidence interval] of maternal cardiovascular events were: 5.7 [5.5–5.8] for preeclampsia, 1.0 [1.0–1.1], 1.4 [0.9–2.2] for stroke, 1.5 [1.2–1.8] for venous thromboembolism, 2.3 [0.9–6.2] for acute coronary syndrome, 3.2 [2.6–3.9] for heart failure and 2.6 [1.4–4.7] for death during PP. The IRR of preeclampsia in women treated during pregnancy vs. women with no HT (5.29 [5.07–5.53]) was significantly higher than in untreated women (3.16 [2.97–3.36]). Among women treated for HT during pregnancy, 435 (2.3%) and 123 (0.7%) bought a renin-angiotensin-blocker at least once during the 2nd and 3rd trimesters, respectively ( Fig. 1 ). Chronic hypertension before pregnancy is a major risk factor of pregnancy and PP adverse outcomes.