Aldosterone as independent predictor of placental and birth weights: Odense child cohort Study

Introduction:

Aldosterone is involved in plasma volume expansion and its levels, along with the levels of other members of the renin-angiotensin-aldosterone system (RAAS), are increased in healthy pregnancy. Aldosterone appears to contribute to an optimal fetal development by enhancing placental growth factor (PlGF) expression and trophoblast cell proliferation.

Hypothesis:

Aldosterone independently contributes to placental and fetal growth.

Methods:

The project is based on data from the Odense Child Cohort, a prospective population-based study from Odense, Denmark, currently with 2500 active families. The participants were recruited between 2010 and 2012. To analyze plasma aldosterone levels and urinary aldosterone excretion (UAldoV), we used a subsample of 607 urine samples (24-h collections) from gestational week 28. Plasma aldosterone and UAldoV were determined by a commercially available ELISA. Predictive values of aldosterone were assessed by multiple regression analysis. Primary outcomes were placental weight (PW) and gestational age-adjusted birth weight Z-score (BW sds).

Results:

UAldoV, but not plasma aldosterone concentration, independently contributed to PW and BW sds (adjusted β coefficients ± SEM: 3.21 ± 1.51, p < 0.05 and 0.04 ± 0.01, p < 0.001, respectively). No significant differences in aldosterone excretion were found between women who later developed preeclampsia and the control group.

Discussion:

At 28 weeks of gestation, 24-h urinary aldosterone excretion was an independent predictor of placental and birth weights. In perspective, mineralocorticoid supplementation could be considered for pregnancies with high risk for IUGR in order to achieve elevated levels of mineralocorticoids and thus benefit placental and fetal development.