Estimating the Proportion of Adverse Pregnancy Outcomes Prevented With Improved Early Pregnancy Cardiovascular Health.

BACKGROUND: More favorable maternal cardiovascular health (CVH) is linked to a lower risk of adverse pregnancy outcomes (APOs). OBJECTIVES: The aim of the study was to estimate the proportion of APOs that could be prevented if maternal CVH was improved. METHODS: Pregnant participants ≥18 years and without prepregnancy hypertension or gestational diabetes from the Nulliparous Pregnancy Outcomes Study were included. First trimester CVH was assessed by current physical activity, diet, sleep, nicotine use, body mass index, and blood pressure. CVH scores ranged from 0 to 100, with higher scores representing better CVH. APOs included new-onset hypertensive disorders of pregnancy, gestational diabetes, and preterm birth. Multivariable logistic regression models assessed the association of early pregnancy CVH and APOs, and impact fractions estimated the proportion of APOs that could be prevented if maternal CVH was improved. RESULTS: Participants (N = 8,927) were 27.2 years (SD: 5.4), and 25.3% experienced an APO. A lower CVH score was associated with a higher APO risk (adjusted OR: 1.46; 95% CI: 1.39-1.54). An estimated 12% of APOs would be prevented if a hypothetical intervention shifted all participants with a CVH score <50 to 50 points (5.8% of participants). Moreover, a dose-response relationship was observed with 15% and 40% of APOs estimated to be prevented if a hypothetical intervention shifted participants with a CVH score <80 to 80 points (51.4% of participants) or shifted everyone to 100 points (96.6% of participants), respectively. Similar findings were observed for each APO subtype. CONCLUSIONS: In this cohort of nulliparous pregnant individuals, potential benefits of improving maternal CVH to reduce APOs are considerable.