Pre-eclampsia and young-onset dementia: time to sound the alarm?

Objective: Pre-eclampsia remains a major cause of maternal and foetal morbidity and mortality worldwide, affecting 2–5% of pregnancies. Many studies have shown the cardiovascular and renal impacts of this disorder to last decades after pregnancy. Recently, an association between pre-eclampsia and neurological disorders has been described with a three-fold higher risk of late-onset vascular dementia after a mean follow-up of 20 years. The aim of our study was to estimate the impact of pre-eclampsia and gestational hypertension in the first years after pregnancy on young-onset dementia. Design and method: The Conception study, a nationwide prospective study including all deliveries occurring in France between 2010 and 2018, with an ongoing follow-up included 1,966,323 women aged over 29 years with no history of dementia. Dementia were identified using primary diagnosis for hospitalization during the follow-up. Hazard Ratios with maternal age as time scale were calculated using crude and adjusted Cox-proportional regression models. Models were adjusted for obesity, diabetes mellitus, tobacco smoking, drug and alcohol addiction and social deprivation. Results: Pre-eclampsia and gestational hypertension occurred in 2.9% and 5.9% of pregnancy respectively. Dementia occurred in 128 women during an average follow-up of 7 years. Pre-eclampsia (but not gestational hypertension) was associated with a 2.7-fold increased risk of young-onset dementia compared with pregnancy without hypertensive disorders (Table 1). The risk of young-onset dementia was even higher when pre-eclampsia occurred early (before 34 weeks of gestation) (4.15 [1.30-13.14]) or was superimposed on chronic hypertension (4.76 [1.49-15.22). Conclusions: While some studies have already reported cognitive function impairment and white matter lesions, our results are the first to show a short-term increase of early-onset dementia. This highlights a need for close follow-up among women who have experienced pre-eclampsia, covering neurological health as well as the metabolic, cardiovascular and renal systems. Moreover, this finding further adds to our currently limited knowledge about risk factors of young-onset dementia. Improving coordination between obstetricians and general practitioners is relevant to enable long-term follow-up of women and to avoid delays in diagnosis due to doctors’ knowledge gaps in their obstetrical history.