Salivary cortisol levels as a predictor of preeclampsia in adolescents

Objective: To determine the usefulness of salivary cortisol as a predictor of preeclampsia in adolescents. Methods: We carried out a nested case- control study. Somatometric, clinical, and biochemical data were obtained from 100 healthy pregnant adolescents and salivary cortisol was measured at 8:00, 12:00, and 20:00 hours on two occasions during pregnancy, before 20 weeks, and after 30 weeks of gestation. The cortisol values between the group of healthy pregnant women and the group that developed preeclampsia were compared by using the Student’s t, Mann-Whitney, and Wilcoxon tests. Also, the ROC curve of cortisol values and the Positive and Negative Predictive values of cortisol were estimated. Results: Values >14.9 nmol/L of cortisol were observed in the group that developed preeclampsia, providing a positive predictive value of 1 (100%). Values <10.1 nmol/L were observed in the control group, the negative predictive value was 1 (100%). The cutoff point of the ROC curve -before 20 weeks of gestation- in the members of the cohort was 13.9 nmol/L. Conclusions: The salivary cortisol values observed in the two evaluations made to each of the groups showed statistically significant differences between the groups at 8 and 12 hours of the day. The values obtained enable establishing gradients that allow separating the group of healthy women that got ill with preeclampsia from the group that did not develop the illness before week 20. After week 30, the cortisol gradients are established more clearly in the group with preeclampsia and in the control group. The validation of these findings in larger samples would allow implementing this procedure as a screening test for preeclampsia in groups of pregnant adolescents.