Cultural stressors influence prenatal maternal cortisol and mental health with consequences for infant outcomes in the Mexican mother-child dyad

Mexican-Americans are a rapidly growing group and report high levels of psychosocial stressors. Fetal exposure to maternal stress is associated altered stress reactivity in infants (via cortisol), a marker for negative developmental outcomes. Acculturation may contribute to increased stress for Mexican-American women. Acculturation involves adapting to a new culture and is associated with poor mental health outcomes. Whether and how stress associated with acculturation contributes to programming of infant outcomes is not clear. This study hypothesized that acculturative stress would be positively related to prenatal maternal cortisol, adverse birth outcomes as well as fetal cortisol, determined by neonatal hair, and acute neonatal salivary cortisol. Salivary cortisol collected 4 times/day to obtain an average daily decline in mothers throughout pregnancy and hair (fetal) and salivary (infant) cortisol from offspring were compared to discrimination, acculturative stress, and cultural values in 52 pregnant women of Mexican descent. Acculturative stress was associated with dysregulation in daily maternal cortisol decline as well as a blunting of the morning rise throughout pregnancy. In addition, increased acculturative stress was associated with longer hospital stays, more total perinatal complications and low birth weight. There was no effect of acculturative or discrimination stress on fetal cortisol levels, however, low familial support and less identification with Mexican cultural values was associated with altered immune function and a larger acute cortisol response to stressors in infants. Cultural stressors may adversely influence the developing fetus and pose a unique perinatal risk for Mexican-Americans, an important public health concern for this vulnerable population.