Associations between prenatal anxiety, discrimination and gestational age at birth

Introduction: Gestational age at birth is one of the strongest predictors of infant mortality and morbidity. Preterm birth (PTB) remains a chronic public health issue in the United States and varies significantly across racial and socioeconomic class, yet remains poorly understood. Evidence regarding the association between maternal stress and spontaneous late PTB is mixed. The objective of this study was to estimate the strength of association between discrimination, prenatal anxiety and gestational age at birth of neonates delivered spontaneously at 34 weeks gestation or later in a population of low SES women. Methods: Study participants were recruited in their first or second trimester of pregnancy from the Women's Health Center at Lattimore. Participants completed the Perceived Stress Scale, Prenatal Distress Questionnaire and the Experiences of Everyday Discrimination Scale during their second and third trimesters of pregnancy. Birth data were obtained from participants' medical records. Medically indicated PTB and all births before 34 completed weeks were excluded from study results. We performed t-tests, ANOVA and linear regression to evaluate associations between prenatal anxiety, discrimination and gestational age at birth. Results: Between December 2011 and January 2013, one hundred and twenty-five women were enrolled in the study with complete data obtained for 98 women. We dichotomized discrimination and prenatal anxiety scores at the 70th and 75th percentiles, respectively, to establish high and low exposure groups. Mean gestational age at birth did not differ between those with high (276.6 days) and low (275.8 days) discrimination exposure (p=.681), nor between those with high (277.0 days) and low (275.7 days) prenatal anxiety exposure (p=.528). Neither discrimination nor prenatal anxiety was independently associated with gestational age at birth after adjustment for maternal age, race/ethnicity, marital status, smoking status, prior PTB and perceived stress. Discussion: Our findings do not support an association between prenatal anxiety or discrimination and gestational age at birth in this population of low SES women. A lower than expected incidence of spontaneous PTB and higher standard deviation in gestational age at birth in the study population limited our ability to detect an association between these psychological stressors and gestational age at birth.