Patient characteristics associated with 17-alpha hydroxyprogesterone caproate use among a high-risk cohort

Preterm birth (PTB) remains a significant cause of neonatal morbidity and mortality. Women with a prior PTB are at risk for recurrent PTB. Treatment with 17-alpha hydroxyprogesterone caproate (17OHP-C) has become standard of care for women with prior PTB to help reduce this risk. Factors that affect a woman's decision to use this medication are largely unknown.

The objective of our study was to investigate patient-level barriers to 17OHP-C. We studied a cohort of women eligible for 17OHP-C with the hypothesis that 17OHP-C is underutilized and certain patient characteristics, such as obstetrical history, influence its use.

A cross-sectional study of all women seen at a specialty prematurity clinic from 2009 through 2013 was performed. Women with a singleton pregnancy were included if they had a prior spontaneous PTB (sPTB). The χ(2) tests were performed for univariate analyses. Multivariable logistic regression was used to control for confounders.

In all, 243 women had 17OHP-C recommended to them based on obstetrical history. There were 218 women with a pregnancy during our study period that were included in our analysis. A total of 163 (74.7%) had documented 17OHP-C use. Women were more likely to accept 17OHP-C if they had a history of a second-trimester loss only (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.17-4.58) or received recommendation for cerclage due to a short cervical length (OR, 4.12; 95% CI, 1.55-10.99). Women with a prior full-term birth were less likely to accept 17OHP-C (OR, 0.48; 95% CI, 0.26-0.89), especially when the prior full-term birth was subsequent rather than prior to the PTB (OR, 0.19; 95% CI, 0.08-0.47). Race, obesity, and insurance status did not impact 17OHP-C use. There was no difference in the rate of sPTB between those who used and did not use 17OHP-C (37.2 vs 34.0%, P = .7).

Obstetric history impacted 17OHP-C use. This study identifies biases regarding 17OHP-C at the patient level and can be used to develop strategies to increase its use. However, the similarity in the sPTB rate between users and nonusers highlights the importance of identifying specific populations where 17OHP-C is and is not effective in preventing PTB.