Abstract Body (Do not enter title and authors here): Background:
Prior studies suggest that angiogenic markers measured during pregnancy may be associated with higher future systolic blood pressure. Furthermore, prior work suggests postpartum body mass index (BMI) influences progression to chronic hypertension among women who experience hypertensive disorders of pregnancy. However, no studies to date have investigated the relationship between levels of angiogenic markers during pregnancy and the future development of obesity among non-obese pregnant women.

Methods:
We included participants in a longitudinal pregnancy biorepository at Brigham and Women’s Hospital (Boston, MA) who had available levels of sFlt-1 (soluble fms-like tyrosine kinase receptor-1) and PlGF (placental growth factor) measured in the third trimester and who continued to follow with primary care in one of the Mass General Brigham institutions up to December 2019, with available covariate and outcome data. We excluded participants with a pre-pregnancy history of obesity (BMI ≥30 kg/m²). The ratio of sFlt-1/PlGF in the third trimester was examined by tertiles. Adjusted mixed effects models were used to test group differences in BMI trends during follow-up.

Results:
Among 590 participants included, the mean (SD) first-trimester BMI was 24 (3) kg/m², and the mean age at delivery was 32 (6) years. Maternal age at delivery and first-trimester BMI were similar across sFlt-1/PlGF tertiles, but participants in the higher tertiles tended to have a slightly lower gestational age at delivery (Table 1). During a median follow-up of 9 years, 173 participants (29%) developed obesity during follow-up. Participants in the second and third tertiles had steeper increases in BMI (+0.22 and +0.24 kg/m², respectively) compared to those in the first tertile (+0.18 kg/m²; p<0.001 for both comparisons) after adjustment for first trimester BMI, race and parity.

Conclusions:
Among participants without a history of pre-pregnancy obesity, higher levels of third-trimester sFlt-1/PlGF ratio were associated with higher BMI during follow-up. Angiogenic marker levels during pregnancy, which are now available and used clinically, may enable opportunistic risk stratification for future cardiometabolic disease.