Practical considerations with 17-Hydroxyprogesterone caproate for preterm birth prevention: does timing of initiation and compliance matter?

J Perinatol. 2019 Sep;39(9):1182-1189. doi: 10.1038/s41372-019-0401-2. Epub 2019 Jun 19.


Objective: Determine whether gestational age of 17-hydroxyprogesterone caproate (17-OHPC) initiation is associated with preterm birth (PTB) risk.

Study design: We performed a retrospective cohort study using MarketScan® data. The primary outcome was PTB < 37 weeks. Rates of PTB were compared between medication initiation at 16-21 weeks versus 21-29 weeks. The association between compliance with weekly 17-OHPC injections and preterm birth rate was tested after adjusting for potential confounding variables.

Result: In all 3374 pregnancies met inclusion criteria. Women with an early 17-OHPC start were less likely to deliver preterm than those with a late start (aRR 0.88; 95%CI 0.79-0.97; p = 0.02). Less compliant patients receiving <25% of recommended doses had a higher PTB rate than those receiving >85% of recommended doses (aRR 1.5; 95%CI 1.2-1.7; p < 0.01).

Conclusion: There is an association between both early 17-OHPC initiation and compliance with reduced rates of PTB.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 17 alpha-Hydroxyprogesterone Caproate / administration & dosage*
  • Adolescent
  • Adult
  • Drug Administration Schedule
  • Estrogen Antagonists / administration & dosage*
  • Female
  • Gestational Age
  • Humans
  • Medication Adherence*
  • Middle Aged
  • Obstetric Labor, Premature / prevention & control
  • Pregnancy
  • Pregnancy Trimester, Second
  • Pregnancy Trimester, Third
  • Premature Birth / prevention & control*
  • Recurrence
  • Retrospective Studies
  • Young Adult


  • Estrogen Antagonists
  • 17 alpha-Hydroxyprogesterone Caproate