Introduction The timing of when a woman is admitted to the hospital for labor care following spontaneous contraction onset may be among the most important decisions that labor attendants make as it can influence care patterns and birth outcomes. The aims of this study were to estimate the percentage of low-risk, nulliparous women at term who are admitted to labor units prior to active labor and to evaluate the effects of the timing of admission (i.e., pre-active versus active labor) on labor interventions and mode of birth. Methods Obstetrics data from low-risk, nulliparous women with spontaneous labor onset at term gestation (N = 216) were merged from two prospective studies conducted at three large, Midwestern hospitals. Baseline characteristics, labor interventions, and outcomes were compared between groups using Fisher’s exact and Mann-Whitney U tests, as appropriate. Likelihoods for oxytocin augmentation, amniotomy, and cesarean delivery were assessed by logistic regression. Results Of the sample of 216 low-risk nulliparous women, 114 (52.8%) were admitted in pre-active labor and 102 (47.2%) were admitted in active labor. Women admitted in pre-active labor were more likely to undergo oxytocin augmentation (84.2% and 45.1%, respectively; odds ratio (OR) 6.5, 95% confidence interval (CI) 3.43–12.27) but not amniotomy (55.3% and 61.8%, respectively; OR 0.8, 95% CI 0.44–1.32) when compared to women admitted in active labor. The likelihood of cesarean delivery was higher for women admitted before active labor onset (15.8% and 6.9%, respectively; OR 2.6, 95% CI 1.02–6.37). Discussion Many low-risk nulliparous women with regular, spontaneous uterine contractions are admitted to labor units before active labor onset, which increases their likelihood of receiving oxytocin and being delivered via cesarean section. An evidence-based, standardized approach for labor admission decision-making is recommended to decrease inadvertent admissions of women in pre-active labor. When active labor cannot be diagnosed with relative certainty, observation before admission to the birthing unit is warranted.

Background Brain-derived neurotrophic factor (BDNF) is implicated as a causal factor in major depression and is critical to placental development during pregnancy. Longitudinal data on BDNF across the perinatal period are lacking. These data are of interest given the potential implications for maternal mood and fetal growth, particularly among Black women who show ~2-fold greater risk for delivering low birth weight infants. Methods Serum BDNF, serum cortisol, and depressive symptoms (per CES-D) were assessed during each trimester and 4–11 weeks postpartum among 139 women (77 Black, 62 White). Low birth weight (<2500 g) was determined via medical record. Results Serum BDNF declined considerably from 1st through 3rd trimesters (ps ≤ 0.008) and subsequently increased at postpartum (p < 0.001). Black women exhibited significantly higher serum BDNF during the 1st trimester, 2nd trimester, and postpartum (ps ≤ 0.032) as well as lower serum cortisol during the 2nd and 3rd trimester (ps ≤ 0.01). Higher serum cortisol was concurrently associated with lower serum BDNF in the 2nd trimester only (p < 0.05). Controlling for race, serum BDNF at both the 2nd and 3rd trimester was negatively associated with 3rd trimester depressive symptoms (ps ≤ 0.02). In addition, women delivering low versus healthy weight infants showed significantly lower serum BDNF in the 3rd trimester (p = 0.004). Women delivering low versus healthy weight infants did not differ in depressive symptoms at any time point during pregnancy (ps ≥ 0.34). Conclusions Serum BDNF declines considerably across pregnancy in Black and White women, with overall higher levels in Blacks. Lower serum BDNF in late pregnancy corresponds with higher depressive symptoms and risk for low birth weight in Black and White women. However, the predictive value of serum BDNF in pregnancy is specific to within-race comparisons. Potential links between racial differences in serum BDNF and differential pregnancy-related cortisol adaptation require further investigation.

Pregnancy is a period of considerable physiological adaption in neuroendocrine, cardiovascular, as well as immune function. Understanding of typical changes in inflammatory immune responses during healthy pregnancy is incomplete. In addition, despite considerable racial difference in adverse pregnancy outcomes, data are lacking on potential racial differences in such adaptation. This repeated measures prospective cohort study included 37 Black and 39 White women who provided blood samples during early, mid-, and late pregnancy and 8–10 weeks postpartum. Peripheral blood mononuclear cells were incubated with lipopolysaccharide (LPS) for 24 hours and supernatants assayed by electrochemiluminescence to quantify interleukin(IL)-6, tumor necrosis factor(TNF)-α, IL-1β, and IL-8 production. While no changes were observed in IL-8 production over time, significant increases in IL-6, TNF-α, and IL-1β production were observed from early to late pregnancy, with subsequent declines approaching early pregnancy values at postpartum (ps<.05). Overall, inflammatory response patterns were highly similar among Black versus White women. However, Black women had greater TNF-α production during mid-pregnancy (p=.002) and marginally lower IL-1β production at postpartum (p=.054). These data show a clear trajectory of change in the inflammatory immune response across pregnancy and postpartum. In this cohort of generally healthy women, Black and White women exhibited minimal differences in LPS-stimulated cytokine production across the perinatal period. Future prospective studies in Black and White women with healthy versus adverse outcomes (e.g., preeclampsia, preterm birth) would inform our understanding of the potential role of immune dysregulation in pregnant women and in relation to racial disparities in perinatal health.

Maternal vitamin D supplementation during pregnancy and lactation alters DNA methylation in mothers and breastfed infants. Additional work is needed to fully elucidate the short- and long-term biologic effects of vitamin D supplementation at varying doses, which could hold important implications for establishing clinical recommendations for prenatal and offspring health promotion.

Preterm birth (PTB) occurs among 1:11 U.S. white women and 1:7.5 African American women and is a significant driver of racial disparities in infant mortality. Maternal stress is the most common clinical phenotype underlying spontaneous PTB. Specific patterns of stress and biological mediators driving PTB remain unclear. We examined the effect of childhood stress on birth timing among African American women and evaluated maternal cortisol elevation as a biological mediator. A prospective observational design was employed, with a single study visit at 28–32 weeks gestation and medical record review. The Stress and Adversity Inventory was administered, which provides a comprehensive estimate of childhood stress, stress in adulthood, and five core characteristic subscales (interpersonal loss, physical danger, humiliation, entrapment, role disruption). Venipuncture was performed between 11:00am and 4:00pm and plasma cortisol quantified by ELISA. Analyses controlled for stress in adulthood. Among a final sample of 89, cumulative childhood stress predicted birth timing (p = .01). The association was driven by stress related to interpersonal loss and physical danger, with support for maternal cortisol as a biological mediator (ab = 0.02, 95% CI [0.001, 0.045]; ab = 0.02, 95% CI [0.001, 0.043], respectively). Results were similar, overall, in sub-group analyses among spontaneously laboring women (n = 53); however, role disruption arose as an additional predictor, as mediated by cortisol elevations (ab = 0.03, 95% CI [0.005, 0.074]). Of note, cortisol was no longer supported as a mediator linking physical danger to birth timing after adjusting for sleep quality and hours awake prior to venipuncture (ab = 0.02, 95% CI [−0.0001, 0.046]). We provide preliminary evidence that, independent of stress in adulthood, childhood stress of specific core characteristics may shape birth timing, with cortisol elevation as a biological mediator. Further investigation is warranted and may bolster the development of biologically-informed screening tools for the prediction and targeted prevention of stress-related PTB.