Interleukin-1 Receptor Antagonist Polymorphism and Birth Timing: Pathway Analysis Among African American Women.

The final analyses included 89 women. This is small for testing genetic and immune pathways. The women were generally healthy and excluded tobacco, alcohol, or illicit drug use after the first trimester, chronic immune conditions, immune-impacting medications, pregnancy complications with immune implications, and fetal anomaly. Results may not apply to higher-risk pregnancies. Birth before term occurred in 5 of the 89 women, lower than the national rate of 13.2%. Birth before full term occurred in 31 of the 89 women, lower than the national rate of 40.4%. This narrows the range of birth timing in the sample. 40.4% of participants underwent induction or pre-labor cesarean section. This makes it harder to assess pathways to spontaneously initiated birth. The paper did not test a clinical screening tool or preventive intervention. It says such tools need future development. The association between IL-1β production and earlier birth was marginal, and the IL-1Ra mediation model was null.

The authors declared no conflicts of interest. The paper is listed as NIH extramural and non-U.S. government supported.

Do not use the GG genotype to predict early birth or change prenatal care. The study was small and observational, and it did not test a clinical tool. It also excluded women with common inflammation-related pregnancy complications, so the association may not apply to higher-risk pregnancies.