Systematic review and meta-analysis of the importance of pre-pregnancy maternal health on the risk of hypertensive disorders of pregnancy.

Stratifying women using their medical history pre-pregnancy may allow early identification of women at high-risk of Hypertensive disorders of pregnancy (HDP), a common and high-burden obstetrical complication. This would allow the establishment of early preventative approaches, however, most research into pregestational conditions comes from data taken during pregnancy. To address this gap, we conducted a systematic review with meta-analysis, adhering to PRISMA and MOOSE guidelines. Our review comprehensively examined the impact of a broad range of medical disorders exclusively diagnosed pre-pregnancy on the development of HDP, including preeclampsia, gestational hypertension, superimposed preeclampsia, eclampsia and HELLP. We searched Medline (OvidSP) and Embase (OvidSP) databases from inception to 8th May 2021 and calculated relative risks ratios, adjusted for study quality, or percentage incidences. 406/8724 studies were included for qualitative research, 177 of which classified for quantitative assessment. HDP risk increased with pregestational renal conditions (7.76, CI: 5.62-10.71), hypertension (3.68, CI: 1.51-8.97), diabetes (3.57, CI: 2.71-4.70), and high body mass index (2.65, CI: 2.33-3.03); as well as with pregestational polycystic ovarian syndrome (1.90, CI: 1.46-2.48), rheumatoid arthritis (1.54, CI: 1.42-1.67), migraines (1.53, CI: 1.32-1.78), and anxiety/depression (1.52, CI: 1.16-2.00). Pregestational antiphospholipid syndrome, systemic lupus erythematosus, and Takayasu arteritis also increased the incidence of gestational hypertension (8 %, 7 %, 17 %) and preeclampsia (37 %, 17 %, 23 %). Overall, this review shows pre-pregnancy maternal health can help stratify HDP risk, and highlights the importance of often-overlooked risk factors in current national guidelines and assessment tools. Crucially, we provide an evidence-based graphical abstract/list of the identified pregestational risk factors as reference for medical practitioners providing pre-pregnancy counselling.