Relationships of Cortisol, Perceived Stress, Genitourinary Infections, and Fetal Fibronectin to Gestational Age at Birth

Abstract

The authors investigated the role of stress and cortisol with patients having preterm labor (PTL) and preterm birth (PTB). The relationships of maternal cortisol, perceived stress, fetal fibronectin (fFN), and genitourinary infections to PTL and PTB were studied. A prospective, longitudinal, observational study (n = 78) was conducted in a private practice in central Texas. Subjects had 4 blood draws for cortisol measurements grouped by 15-19, 20-22, 23-26, 27-30, and 31-35 weeks of gestation. Subjects had 2 vaginal swabs forfFN, chlamydia, and bacterial vaginosis screens at 23-26 and 27-30 weeks with assessment of psychosocial stress at 23-26 and 31-35 weeks. Statistical analysis was by analysis of variance, Pearson correlations, Fisher exact test, and logistic regression. There were no significant differences between the PTB, PTL, and term groups on cortisol levels at any of the gestational periods. Cortisol concentrations at any gestational stage did not correlate with gestational age at birth. A relationship of cortisol to race was observed when comparing Caucasians to other ethnic groups. A correlation (r = 0.42, P < 0.001) between the change in Perceived Stress Scale (PSS) score and gestational age was observed. The greater the decrease in PSS scores, the longer was the gestational age. A significant increase in cortisol at 19-21 weeks (P < 0.04), 23-26 weeks (P < 0.05), and 31-35 weeks (P < 0.01) was observed in patients having genitourinary infection. PTL was also significantly increased in subjects having positive genitourinary infections at either 23-26 weeks or 27-30 weeks (P < 0.01). The sensitivity of fFN to predict PTL collected at 27-30 weeks was 40%, specificity 86%, positive predictive value 55%, and negative predictive value 83%. These results indicate that cortisol is a poor predictor of either PTL or PTB. A decrease in perceived stress during the 2nd trimester was associated with an increase in length of gestation, suggesting the possibility of stress reduction as an appropriate intervention for lengthening gestational age.

The Relationship between Prenatal Stress, Depression, Cortisol and Preterm Birth: A Review

“…Few studies (Erickson et al, 2001;Hobel et al, 1999;Kramer et al, 2009) support the hypothesis that cortisol levels increase with maternal stress. However, the Ruiz et al (2001) study does not support the hypothesis that cortisol levels increases with stress, but it shows a significant relationship between stress and gestational age. Moreover, Shaikh et al (2011) did not find any relationship between stress, cortisol and preterm birth.…”

“…The studies that examine the relationship between maternal stress, cortisol and preterm birth together at the same time have inconsistent findings (see Table 1) (Erickson et al, 2001;Hobel et al, 1999;Kramer et al, 2009;Ruiz et al, 2001;Shaikh et al, 2011). Few studies (Erickson et al, 2001;Hobel et al, 1999;Kramer et al, 2009) support the hypothesis that cortisol levels increase with maternal stress.…”

“…Many studies demonstrate an association between stress and preterm birth (Copper et al, 1996;Erickson et al, 2001;Hobel et al, 1999;Jesse et al, 2009;Ruiz et al, 2001). Copper et al, in a prospective study, enrolled 2593 pregnant women between 25 to 29 weeks of gestation and demonstrated that stress was significantly associated with spontaneous preterm birth and low birth weight.…”

“…Moreover, Kramer, Lydon, et al (2009) prospectively recruited 5337 pregnant women of Montreal and conducted a nested case-control study. But, Ruiz et al (2001) conducted a prospective, longitudinal, observational study in which 78 women were recruited and followed till delivery and divided into three groups: normal term (n = 53), preterm labor (n = 17), and preterm birth groups (n = 6). Shaikh (2011) conducted a prospective cohort study in which 132 women were recruited between 28 -30 weeks of pregnancy and followed till delivery.…”

“…ACTH stimulates the adrenal cortex to secrete cortisol hormone (Diego et al, 2009;Giurgescu, 2009;Ruiz et al, 2001) and the adrenal medulla to secrete norepinephrine and epinephrine (Holzman et al, 2009). Increased cortisol levels further signal the hypothalamus and pituitary gland in a negative feedback loop to decrease CRH production.…”