Racial and ethnic disparities in use of 17-alpha hydroxyprogesterone caproate for prevention of preterm birth Presented orally (abstract no. 18) at the 36th annual meeting of the Society for Maternal-Fetal Medicine, Atlanta, GA, Feb. 1-6, 2016.

Background Racial/ethnic disparities in preterm birth remain a major public health challenge in the United States. While 17-alpha hydroxyprogesterone caproate (17OHP-C) is recommended for preterm birth prevention in women with a prior preterm birth, non-Hispanic black women continue to experience higher rates of recurrent preterm birth than white women receiving the same treatment. Further investigation of disparities in 17OHP-C use and adherence is warranted. Objective We sought to evaluate whether racial and ethnic disparities exist in the use of and adherence to 17OHP-C within a population of eligible women. Study Design This was a retrospective cohort study of women with a prior spontaneous, singleton preterm birth who were eligible for 17OHP-C for preterm birth prevention and received care at a single institution from 2010 through 2014. Associations between self-identified race/ethnicity (non-Hispanic black vs women in all other racial/ethnic groups) and documented counseling about 17OHP-C, receipt of any 17OHP-C, and adherence to 17OHP-C administration were each estimated by bivariable analysis and multivariable logistic regression. Adherence to 17OHP-C was defined as not >1 missed dose, initiation <20 weeks' gestational age, and continuation until 37 weeks or delivery. Results Of 472 women who were clinically eligible for 17OHP-C, 72% (N = 296) had documented 17OHP-C counseling and 48.9% (N = 229) received 17OHP-C. There were no differences in likelihood of 17OHP-C counseling or receipt of 17OHP-C based on race/ethnicity. While overall 83% (N = 176) of women were adherent to 17OHP-C, only 70% (N = 58) of non-Hispanic black women were adherent, compared to 91% (N = 118) of all other women (P <.001). Non-Hispanic black women had more missed doses (2.4 vs 0.4 doses, P <.001) and later initiation of care (12.0 vs 10.2 weeks, P <.001) than women in other racial/ethnic groups. After adjustment for potential confounders, non-Hispanic black women were significantly less likely to be adherent to 17OHP-C (adjusted odds ratio, 0.16; 95% confidence interval, 0.04-0.65). A significant interaction between non-Hispanic black race/ethnicity and public insurance was identified (adjusted odds ratio, 0.16; 95% confidence interval, 0.05-0.52). Conclusion In a diverse cohort of women eligible for preterm birth prevention, non-Hispanic black women are at an increased risk of nonadherence to 17OHP-C. Non-Hispanic black women with public insurance are at a particularly increased risk of nonadherence.