[Plasma cortisol by trimester of pregnancy: study from an Argentine hospital]

Maternal cortisol undergoes variations in its levels secondary to physiological adaptations. Maternal cortisol secretion increases from the 25th week of pregnancy, estimated to reach twice the value of nonpregnant women in the third trimester. The objectives of this study were to demonstrate the increase in cortisol values in pregnancy and establish reference ranges of plasma cortisol trimester specific to our population of healthy pregnant women.

Cortisol measurement was performed in 186 healthy pregnant women between 2020 and 2023, 62 women were analyzed for each trimester of pregnancy, including age, body mass index (BMI), previous pregnancies, glycemia and ionogram.

The median age was 27 (18 - 47) years, previous pregnancies 1 (0-9), BMI 25.7 (16.6 - 46.2) kg/m2. In the first trimester, the median cortisol level was 14.1 (7.53 - 31.0) ug/dL; in the second trimester 20.5, (10.0 - 47.2) ug/dl and in the third trimester 23.2, (11.8 - 33.1) ug/dL. The increase in cortisol throughout the trimesters was statistically significant p < 0.001.

In this study, cortisol values were identified by specific trimester, which could show an increase throughout pregnancy. Having reference values allows for proper interpretation and clinical diagnosis of endocrine diseases at this stage of life.