Each year in the United States, more than 500,000 neonates are born before 37 weeks of gestation. Women who have experienced a previous preterm birth are at high risk
of recurrence. A weekly prenatal injection of 17a-hydroxyprogesterone caproate decreases the risk of recurrent preterm birth and is recommended from as early as 16
weeks of gestation in women carrying singleton pregnancies who have a history of spontaneous singleton preterm birth. A commonly used metric for public health program effectiveness is population coverage of an intervention. In the case of 17a-hydroxyprogesterone caproate, population coverage can be defined as the proportion of women who are eligible for 17a-hydroxyprogesterone caproate
(ie, previous pregnancy complicated by spontaneous singleton preterm birth) who actually receive the intervention. To receive a full course of 17a-hydroxyprogesterone
caproate, women must negotiate a complex series of steps that includes presenting early for prenatal care, being identified as eligible for 17a-hydroxyprogesterone caproate, being offered 17a-hydroxyprogesterone caproate, accepting 17a-hydroxyprogesterone caproate, and adhering to the weekly 17a-hydroxyprogesterone caproate dose schedule. We describe this series of steps as well potential solutions to increase 17a-hydroxyprogesterone caproate coverage.