A potential role for allostatic load in preeclampsia.

Preeclampsia is a multisystemic disorder of pregnancy associated with maternal and fetal complications as well as later-life cardiovascular disease. Its exact cause is not known. We developed a pregnancy-specific multisystem index score of physiologic risk and chronic stress, allostatic load (AL), early in pregnancy. Our objective was to determine whether AL measured early in pregnancy was associated with increased odds of developing preeclampsia. Data were from a single-center, prospectively collected database in a 1:2 individual-matched case control of women enrolled at <15 weeks gestation. We matched 38 preeclamptic cases to 75 uncomplicated, term deliveries on age, parity, and lifetime smoking status. AL was determined using 9 measures of cardiovascular, metabolic, and inflammatory function. Cases and matched controls were compared using conditional logistic regression. We compared the model's association with preeclampsia to that of obesity, a well-known risk factor for preeclampsia, by assessing goodness-of-fit by Akaike information criterion (AIC), where a difference >1-2 suggests better fit. Early pregnancy AL was higher in women with preeclampsia (1.25 ± 0.68 vs. 0.83 ± 0.62, p = 0.002); women with higher AL had increasing odds of developing preeclampsia (OR 2.91, 95 % CI 1.50-5.65). The difference between AIC for AL and obesity was >2 (AIC 74.4 vs. 84.4), indicating AL had a stronger association with preeclampsia. Higher allostatic load in early pregnancy is associated with increasing odds of preeclampsia. This work supports a possible role of multiple maternal systems and chronic stress early in pregnancy in the development of preeclampsia.