Psychobiological markers of stress in pregnancy: 6-sulfatoxymelatonin - A longitudinal study

Maternal stress, physical and psychological, has been associated with adver se pregnancy outcome. The pineal gland is a physiological transducer that r eflects adrenergic input. In a recent pilot study, we found urinary 6-sulia toxymelatonin, the melatonin metabolite, to be elevated after a women spent a day at work compared to levels after a day off work, a leisure day. To e valuate the value of melatonin as a marker of stress, we evaluate melatonin metabolite levels in 121 women, along with perceived anxiety levels and ur inary cortisol. Urinary cortisol and maternal anxiety levels each were sign ificantly higher after a work day compared to a leisure day p =.03 and p =. 001, respectively. 6-sulfatoxymelatonin was not significantly different bet ween work and leisure. Changes in cortisol levels were correlated with chan ges in melatonin metabolite levels (r =.62, p =.001). There was no correlat ion between changes in anxiety between work and leisure and changes in 6-su lfastoxymelatonin. We found no correlation with 28 week 6-sulfatoxymelatoni n or 28-week cortisol and birth weight or gestational age at delivery. Resu lts of this study suggest that melatonin secretion may not be a valuable ma rker for stress in pregnancy.