The morning and late-night salivary cortisol ranges for healthy women may be used in pregnancy

Objectives The diagnosis of adrenal dysfunction in pregnancy and in women taking oral contraceptives remains a diagnostic challenge. Salivary cortisol seems to be a useful tool for the diagnosis of Cushing's syndrome and adrenal insufficiency. However, the changes in salivary cortisol concentration in healthy pregnancy are not clearly defined. Design The aim of our study was to compare diurnal changes in salivary cortisol in healthy pregnant women, healthy controls and women on oral contraceptives. Patients The study groups consisted of (i) 41 healthy pregnant women, (ii) 42 healthy women and (iii) 12 healthy women on oral contraceptives. Measurements Serum and salivary cortisol in the morning and salivary late-night cortisol were measured with Roche ECLIA cortisol test (Elecsys 2010) in each trimester and postpartum. Results Despite the elevation of morning serum cortisol in the second and third trimesters of pregnancy, the morning salivary values as well as late-night salivary cortisol throughout all trimesters were not significantly different from control values (P > 0.5). In the postpartum period, the morning and late-night salivary cortisol values were significantly lower than in late pregnancy. The morning and late-night salivary cortisol values in women on contraceptives were also not different from those in the healthy women group. Conclusion The results of our study suggest that reference values for salivary cortisol established for a healthy adult population can be used for pregnant women and women on oral contraceptives in the initial diagnostic testing for Cushing's syndrome and adrenal insufficiency.