Circadian cortisol dynamics across reproductive stages and in relation to breastfeeding in the Philippines.

These findings are consistent with known alterations in hypothalamic-pituitary-adrenal axis function during reproduction, and in particular point to marked and progressive elevation in maternal cortisol during the course of gestation. Cortisol appears to return to nulliparous levels after parturition, with levels suppressed below nulliparous levels during lactation.