Excretion of urinary steroids in pre- and postpartum female baboons

Steroid hormones are important regulators of a wide variety of reproductive and behavioral functions. We investigated the ability to track sex steroids and glucocorticoids in urine samples collected noninvasively from pre- and postpartum female baboons. Paired plasma and urine samples were collected every 2 weeks prior to and following birth in 10 females. Changes in concentrations of plasma steroids (estradiol, progesterone, and cortisol) were reflected in changes in urinary metabolite excretion (estrone conjugates, pregnanediol conjugates, and cortisol; r's0.36, p's<0.001). A low correlation between prepartum plasma and urinary cortisol may reflect late-gestational changes in the production and/or metabolism of glucocorticoids. Steroid excretion profiles in a large sample of females giving birth and caring for healthy infants (n=108) were compared with profiles obtained from females with poor maternal-fetal outcomes (late-term stillbirth, n=14) and from females with significant postpartum problems with maternal care (n=20). Mothers giving birth to stillborn infants had lower prepartum levels of urinary estrone conjugates and cortisol, suggesting reduced placental steroidogenesis. Mothers with postpartum behavioral difficulties had higher concentrations of prepartum estrone excretion, lower cortisol excretion, and elevated E/P ratios throughout the peripartum period. Noninvasive sample collection and enzyme immunoassay, therefore, have predictive utility regarding circulating steroid concentrations and can identify important endocrine correlates of physiological and behavioral abnormalities in baboons.