Prenatal maternal stress programs infant stress regulation

Abstract

Objective: Prenatal exposure to inappropriate levels of glucocorticoids (GCs) and maternal stress are putative mechanisms for the fetal programming of later health outcomes. The current investigation examined the influence of prenatal maternal cortisol and maternal psychosocial stress on infant physiological and behavioral responses to stress.

Methods: The study sample comprised 116 women and their full term infants. Maternal plasma cortisol and report of stress, anxiety and depression were assessed at 15, 19, 25, 31 and 36 + weeks' gestational age. Infant cortisol and behavioral responses to the painful stress of a heel-stick blood draw were evaluated at 24 hours after birth. The association between prenatal maternal measures and infant cortisol and behavioral stress responses was examined using hierarchical linear growth curve modeling.

Results: A larger infant cortisol response to the heel-stick procedure was associated with exposure to elevated concentrations of maternal cortisol during the late second and third trimesters. Additionally, a slower rate of behavioral recovery from the painful stress of a heel-stick blood draw was predicted by elevated levels of maternal cortisol early in pregnancy as well as prenatal maternal psychosocial stress throughout gestation. These associations could not be explained by mode of delivery, prenatal medical history, socioeconomic status or child race, sex or birth order.

Conclusions: These data suggest that exposure to maternal cortisol and psychosocial stress exerts programming influences on the developing fetus with consequences for infant stress regulation.

Figure 1

Figures A and B illustrate the trajectory of maternal cortisol across gestation that is associated with the infant cortisol response to the heel-stick. Data were analyzed continuously using growth curve modeling. For illustrative purposes, prenatal maternal cortisol trajectories (with standard error bars) are displayed for mothers of infants with the highest cortisol response (top quartile) and the lowest cortisol response (bottom quartile) at 20 minutes (Figure 1A) and 40 minutes (Figure 1B) after the heel-stick.

Figure 2

This figure illustrates the infant cortisol profile that is associated with high (top quartile) and low (bottom quartile) prenatal maternal cortisol. Data are presented based on maternal cortisol at 25 weeks’ gestation; the point with the strongest association between prenatal maternal cortisol and infant cortisol response to the heel-stick procedure based on growth curve models. Note: Both maternal cortisol and infant cortisol were analyzed as continuous variables. For graphing purposes we have presented data based on the top and bottom quartile.

Figure 3

The trajectory of maternal cortisol across gestation that is associated with infant behavioral recovery scores is presented. Although data were analyzed continuously using growth curve modeling, for graphing purposes the trajectory of cortisol across gestation (with standard error bars) is shown for the mothers of infants with the highest behavioral recovery scores (top quartile) and the lowest behavioral recovery scores (bottom quartile).

Figure 4

This figure illustrates the pattern of behavioral responses that is associated with maternal cortisol. Behavioral state scores are presented for infants born to mothers with high (top quartile) or low (bottom quartile) cortisol levels at 13 weeks’ gestation (the point with the strongest association between prenatal maternal cortisol and infant behavioral responses to the heel-stick procedure based on HLM analyses).

Figure 5

The trajectory of perceived stress across gestation associated with infant behavioral recovery scores is presented. Although data were analyzed continuously using growth curve modeling, for graphing purposes the trajectory of perceived stress across gestation (with standard error bars) is presented for the mothers of infants with the highest behavioral recovery scores (top quartile) and the lowest behavioral recovery scores (bottom quartile).

Figure 6

The pattern of behavioral responses that is associated with maternal perceived stress is shown. Behavioral state scores are presented for infants born to mothers with high (top quartile) and low (bottom quartile) perceived stress at 13 gestational weeks (the point with the strongest association between prenatal maternal perceived stress and infant behavioral responses to the heel-stick procedure based on HLM analyses).