Abstract Body: Introduction: Hypertensive disorders of pregnancy (HDPs) are rising in the United States, leading to increased maternal mortality, future pregnancy complications, and cardiovascular disease (CVD) risk factors like hypertension and diabetes. Studies suggest that HDPs have different etiologies than non-pregnancy hypertensive disorders, and it is unclear whether behavioral and lifestyle risk factors for CVD in general are similar for HDPs.

Hypothesis: We hypothesized that women with lower levels of physical activity early in pregnancy would have a higher risk for HDPs.

Methods: We analyzed data from pregnant women in California with overweight or obesity enrolled in the Goals for Reaching Optimal Wellness (GROWell) trial. A logistic regression model was used to assess the association between physical activity in early pregnancy (10-16 weeks) and later HDPs (gestational or chronic hypertension, or preeclampsia) while controlling for diet, depression, anxiety, sleep, and factors such as age, parity, BMI, maternal education, and race. Physical activity was measured in metabolic equivalents using the pregnancy physical activity (PPAQ) survey.

Results: Among 453 participants, 38 (~8.4%) experienced HDPs. Average age for participants was 33.6 ± 4.1 years, 59% identified as a member of a historically minoritized group. Lower physical activity levels were associated with an increased risk of developing HDPs later in pregnancy (OR = 0.98, p = 0.003), after controlling for diet quality, sleep, mood, and demographics. The association between lower PPAQ scores and HDPs was significant for light-intensity (OR = 0.98, p = 0.04), moderate-intensity (OR = 0.97, p = 0.008), and household/caregiving activities (OR = 0.98, p = 0.006).

Conclusion: Low physical activity levels in early pregnancy may contribute to the risk of developing HDPs. Importantly, general activity and light to moderate intensity physical activity demonstrated benefit, suggesting that even small increases in activity may be protective. Future research with larger samples should explore the role of different kinds of activity in the prevention of HDPs, especially for women with overweight or obesity, where physical inactivity may compound the risk for adverse pregnancy outcomes.