PRENATAL PSYCHOSOCIAL FACTORS AND THE NEUROENDOCRINE AXIS IN HUMAN-PREGNANCY

Objective: Physiological processes including neuroendocrine function h ave been proposed as mediators of the relationship between prenatal ps ychological state and pregnancy outcome; however, there are virtually no human studies that have systematically assessed such mechanisms. Ne uroendocrine processes are significantly altered during pregnancy, and are characterized by the evolution of a transient neuroendocrine syst em, the placenta, and modifications in endocrine control mechanisms, B ecause these alterations have implications for neuroendocrine responsi vity to exogenous conditions, the aim of the present study was to exam ine the cross-sectional association between prenatal psychosocial fact ors and stress-related neuroendocrine parameters during human pregnanc y. Method: Fifty-four adult women with a singleton, intrauterine pregn ancy were recruited before 28 weeks of gestation. Maternal antecubital venous blood samples were withdrawn at 28 weeks of gestation for bioa ssays of adrenocorticotropin hormone (ACTH), beta-endorphin (beta E), and cortisol, Measures of prenatal stress, social support, and persona lity were collected using a two-part, self-report questionnaire admini stered at 28 and 30 weeks of gestation. Biomedical data were obtained from the medical record. Factors known to influence neuropeptide and h ormone levels during pregnancy were controlled, including gestational age, circadian variation, and obstetric risk. Results: In the present sample, prenatal psychosocial stress, social support, and personality variables were associated with neuroendocrine parameters in two primar y ways, First, certain psychosocial factors were significantly associa ted with plasma levels of ACTH, beta E, and cortisol, and second, psyc hosocial factors were associated with a measure of disregulation of th e normal relationship between two pro-opiomelanocortin (POMC) derivati ves, ACTH and beta E, Furthermore, a combination of the maternal psych osocial and sociodemographic factors during pregnancy accounted for 36 % of the variance in ACTH, 22% of the variance in the ACTH-beta E disr egulation index, 13% of the variance in cortisol, and 3% of the varian ce in beta E. Conclusions: The present findings are consistent with th e premise that maternal-placental-fetal neuroendocrine parameters are significantly associated, both in magnitude and specificity, with feat ures of maternal psychosocial functioning in pregnancy despite the sys temic alterations associated with the endocrinology of pregnancy. Thes e findings provide a basis for further investigations of the role of t he neuroendocrine system as a putative mediating pathway between prena tal psychosocial factors and birth outcome, and possibly also as a mec hanism linking features of the maternal psychosocial environment to fe tal/infant brain development.