Second trimester corticotropin-releasing hormone levels in relation to preterm delivery and ethnicity

Obstet Gynecol. 2001 May;97(5 Pt 1):657-63. doi: 10.1016/s0029-7844(00)01209-6.


Objective: To assess the relationship between maternal corticotropin-releasing hormone (CRH) levels in second trimester sera, and the risk of preterm delivery in an ethnically heterogeneous sample of pregnant women.

Methods: This nested case-control study included two case groups (97 women who delivered before 35 weeks' gestation, 144 who delivered at 35--36 weeks' gestation), and a control group (244 women who delivered at or after 37 weeks' gestation) frequency matched by ethnicity (black, white) and by alpha-fetoprotein levels (normal, unexplained high). Corticotropin-releasing hormone was evaluated in stored maternal sera collected at 15--19 weeks' gestation from cases and controls.

Results: Delivery before 35 weeks' gestation was associated positively with a second trimester, ethnic-specific CRH above 1.5 multiples of the median in white women [odds ratio (OR) 2.3, 95% confidence interval (CI) 1.1, 5.1] and black women (OR 5.0, 95% CI 1.8, 13.3). Sensitivity was 29% in whites and 41% in blacks; specificity was 84% in whites and 80% in blacks. We estimated the positive and negative predictive values to be 6% and 97%, respectively, in white women, and 16% and 93%, respectively, in black women. It was also noted that, within case and control groups, black women had consistently lower CRH levels than white women.

Conclusion: Factors that lead to a premature increase in placental CRH production and are associated with an increased risk of preterm birth are evident as early as 15--19 weeks' pregnancy. When considering potential links between stressors, placental changes, CRH levels, and preterm birth, it might be important to stratify or adjust for ethnicity.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • African Continental Ancestry Group*
  • Biomarkers / analysis
  • Case-Control Studies
  • Cohort Studies
  • Corticotropin-Releasing Hormone / analysis*
  • European Continental Ancestry Group*
  • Female
  • Humans
  • Incidence
  • Mass Screening / methods*
  • Obstetric Labor, Premature / diagnosis
  • Obstetric Labor, Premature / ethnology*
  • Obstetric Labor, Premature / metabolism
  • Pregnancy
  • Pregnancy Outcome*
  • Pregnancy Trimester, Second
  • Probability
  • Reference Values
  • Risk Assessment
  • Sampling Studies
  • Sensitivity and Specificity


  • Biomarkers
  • Corticotropin-Releasing Hormone