Progesterone therapy for prevention of recurrent spontaneous preterm birth in a minority patient population: a retrospective study.

BACKGROUND: Preterm birth is a leading cause of infant morbidity and mortality worldwide. The burden of prematurity underscores the need for effective risk reduction strategies. The purpose of this study is to evaluate the efficacy of progesterone therapy, both intramuscular 17-α-hydroxyprogesterone caproate (IM 17-OHPC) and vaginal progesterone, in the prevention of recurrent spontaneous preterm birth (sPTB). The co-primary outcomes included: recurrent spontaneous PTB < 37 and < 34 weeks' gestation. METHODS: This retrospective cohort study included 637 pregnant patients that delivered at any of the three hospitals within the Los Angeles County healthcare system between October 2015 and June 2021. We compared frequencies of measured variables between each of the progesterone treated groups to no treatment using Pearson chi-squared tests and independent t-tests for categorical and continuous variables, respectively. We estimated crude and adjusted associations between each specific treatment (versus no treatment) and primary outcomes using logistic regression. RESULTS: Recurrent sPTB < 37 weeks' gestation occurred in 22.3% (n = 64) of those in the no treatment group, 29.1% (n = 86, p = .077) in the 17-OHPC group, and 14.3% (n = 6, p = 0.325) in the vaginal progesterone group. Recurrent sPTB < 34 weeks' gestation was 6.6% (n = 19) in the no treatment group, 11.8% (n = 35, p = .043) in the 17-OHPC group, and 7.1% (n = 3, p = 1) in the vaginal progesterone group. Among all participants, neither 17-OHPC nor vaginal progesterone was significantly associated with a reduction in recurrent sPTB at any time point. Among those with a short cervix, IM 17-OHPC was positively associated with recurrent sPTB < 37 weeks' gestation (aOR 5.61; 95% CI 1.16, 42.9). CONCLUSIONS: Progesterone therapy of any type did not reduce the risk of recurrent sPTB < 34 or < 37 weeks' gestation compared to no progesterone therapy.

Society for Maternal-Fetal Medicine Statement: Response to the Food and Drug Administration's withdrawal of 17-alpha hydroxyprogesterone caproate.

On April 5, 2023, the US Food and Drug Administration withdrew the approval of 17-alpha hydroxyprogesterone caproate, effective immediately, because of the lack of evidence that it reduces the risk of recurrent spontaneous preterm birth. This decision withdraws approval for all formulations of 17-alpha hydroxyprogesterone caproate (both intramuscular and subcutaneous) and applies to both brand name (Makena) and generic versions of the medication. We agree with the Food and Drug Administration determination and discourage continued prescribing of 17-alpha hydroxyprogesterone caproate, including through compounding pharmacies. We do not recommend changing indications for cerclage, indications for vaginal progesterone in patients with a short cervix, or recommendations against activity restriction based on the Food and Drug Administration withdrawal of 17-alpha hydroxyprogesterone caproate from the market. We recommend that discussion of the use of vaginal progesterone for primary prevention of recurrent preterm birth without input of cervical length or in those with a cervical length of ≥25 mm includes a shared decision-making process, especially if a progesterone formulation for preterm birth prevention was received in a previous pregnancy. The Food and Drug Administration determined that it would be inappropriate to delay the effective date of the withdrawal to allow patients currently receiving 17-alpha hydroxyprogesterone caproate to finish treatment. We agree with the Food and Drug Administration that there is no evidence of benefit with continued treatment. Patients currently receiving 17-alpha hydroxyprogesterone caproate can be counseled that the Food and Drug Administration's Center for Drug Evaluation and Research has not identified evidence of harm from discontinuation before 37 weeks of gestation.

Racial and ethnic representation in 17-hydroxyprogesterone caproate preterm birth prevention studies: a systematic review.

OBJECTIVES: The US preterm birth rate varies dramatically by race and ethnicity yet the racial and ethnic representation within studies evaluating 17-hydroxprogesterone caproate (17-P) for preterm birth prevention is unknown. The objectives of our study were to 1) examine the racial and ethnic representation of participants in 17-P preterm birth prevention studies, 2) evaluate adherence to the NIH race and ethnicity reporting guidelines and 3) compare racial and ethnic representation in research studies to national preterm birth incidence. METHODS: We systematically reviewed US studies published between January 2000 and December 2019. Study participant's race and ethnicity were reported using descriptive statistics then compared to US 2017//2018 preterm birth data using Pearson's chi-square. RESULTS: Eighteen studies met the inclusion criteria, 17 studies reported race, 11 studies reported ethnicity, and yet none of the studies followed the NIH criteria. Compared to 2017/2018 US preterm births, the proportion of black/African American study participants was significantly higher whereas the proportions of all other race categories were lower. CONCLUSIONS: More detailed reporting of race and ethnicity is needed in 17-P literature. Black women appear to be well represented while other racial and ethnic groups may be understudied.

A chronicle of the 17-alpha hydroxyprogesterone caproate story to prevent recurrent preterm birth.

Preterm birth is a substantial public health concern. In 2019, the US preterm birth rate was 10.23%, which is the fifth straight year of increase in this rate. Moreover, preterm birth accounts for approximately 1 in 6 infant deaths, and surviving children often suffer developmental delay or long-term neurologic impairment. Although the burden of preterm birth is clear, identifying strategies to reduce preterm birth has been challenging. On October 29, 2019, a US Food and Drug Administration advisory committee voted 9 vs 7 to withdraw interim accelerated approval of 17-alpha hydroxyprogesterone caproate for preventing recurrent preterm birth because the called for a confirmatory trial, known as the Prevention of Preterm Birth in Women With a Previous Singleton Spontaneous Preterm Delivery trial, was not confirmatory. The Prevention of Preterm Birth in Women With a Previous Singleton Spontaneous Preterm Delivery trial included subjects enrolled in the United States and Canada to ensure that at least 10% of patients would be from North America; however, this trial took 9 years to complete and did not demonstrate significant treatment effects in the 2 primary outcomes of interest. Delivery before 35 weeks' gestation occurred in 122 of 1130 women (11%) given 17-alpha hydroxyprogesterone caproate compared with 66 of 578 women (11.5%) given placebo (relative risk, 0.95; 95% confidence interval, 0.71-1.26; P=.72). Similarly, the coprimary outcome neonatal composite index occurred in 61 of 1093 women (5.6%) given 17-alpha hydroxyprogesterone caproate compared with 28 of 559 women (5.0%) given placebo (relative risk, 1.12; 95% confidence interval, 0.68-1.61; P=.73). There was also a lack of efficacy for 17-alpha hydroxyprogesterone caproate treatment in the analysis of a variety of secondary outcomes. Like the Maternal-Fetal Medicine Units Network trial, the Prevention of Preterm Birth in Women With a Previous Singleton Spontaneous Preterm Delivery trial was also flawed. Importantly, the Maternal-Fetal Medicine Unit Network trial was the sole justification for treating women in the United States with 17-alpha hydroxyprogesterone caproate for nearly 2 decades. Currently, despite more than half a century, 17-alpha hydroxyprogesterone caproate still has not been found to be clearly effective. In this context, how does the advising physician dependent on scientific evidence advise a patient that 17-alpha hydroxyprogesterone caproate is effective when the evidence to support this advice has repeatedly been found to be inadequate? This clinical opinion is a critical appraisal of the 2 randomized trials examining the efficacy of 17-alpha hydroxyprogesterone caproate to prevent recurrent preterm birth and a chronicle of events in the regulatory process of drug approval to help answer this question. With this examination, these events illustrate the complexity of pharmaceutical regulations in the era of accelerated Food and Drug Administration approval and characterize the financial impact and influence in medicine. In this report, we also emphasize the value of observational studies in contemporary practice and identify other examples in medicine where accelerated Food and Drug Administration approval has been withdrawn. Importantly, the themes of the 17-alpha hydroxyprogesterone caproate story are not limited to obstetrics. It can also serve as a microcosm of issues within the US healthcare system, which ultimately contributes to the high cost of healthcare. In our opinion, the answer to the question is clear-the facts speak for themselves-and we believe 17-alpha hydroxyprogesterone caproate should not be endorsed for use to prevent recurrent preterm birth in the United States.

Preventing recurrent preterm birth with 125 mg of 17-alpha-hydroxyprogesterone caproate.

AIM: There is strong evidence that weekly intramuscular (IM) injections of 250 mg of 17-alpha-hydroxyprogesterone caproate (17-OHPC) reduce the risk of recurrent preterm birth (PTB); however, whether a lower dose of 17-OHPC could reduce the risk of recurrent PTB remains unclear. This study aimed to assess whether 125 mg of 17-OHPC reduces recurrent PTB among women with a prior singleton spontaneous PTB and cervical length >25 mm. METHODS: This retrospective cohort study at a tertiary-care medical center in Japan included women with a prior singleton spontaneous PTB between 20 and 36 weeks' gestation and cervical length >25 mm, between 2008 and 2018. Primary outcomes were PTB <37 and <34 weeks' gestation. We calculated the adjusted odds ratio (aOR) and 95% confidence interval (CI) using a multiple logistic regression model. Gestational age at delivery was compared using the Kaplan-Meier survival curve and log-rank test. RESULTS: Overall, 173 women met the inclusion criteria. Eighty-four women received weekly injections of 125 mg of 17-OHPC, and 89 did not. Treatment with 125 mg of 17-OHPC significantly reduced the risk of recurrent spontaneous PTB <37 (aOR: 0.156 [95% CI: 0.049-0.497]) and <34 weeks' gestation (aOR: 0.156 [95% CI: 0.049-0.497]). The mean delivery gestational age was also significantly longer in the 17-OHPC group (log-rank p = 0.005). CONCLUSIONS: In this study population, weekly IM injections of 125 mg of 17-OHPC reduced the risk of recurrent PTB <37 and <34 weeks' gestation.

Successful treatment of severe intra-amniotic inflammation and cervical insufficiency with continuous transabdominal amnioinfusion and cerclage: A case report.

Severe intra-amniotic inflammation, even with a negative bacterial culture, can lead to premature labor. We report a 43-year-old multiparous woman with severe intra-amniotic inflammation and cervical insufficiency at 23 weeks and 5 days of gestation. Continuous transabdominal amnioinfusion was started 2 days after the diagnosis. The amniotic fluid interleukin-6 level normalized after 2 days of treatment. She underwent Shirodkar cervical cerclage on day 7. Despite termination of amnioinfusion and catheter removal on day 16, the pregnancy was maintained without any subsequent treatment. At 33 weeks and 5 days of gestation, an intrauterine Ureaplasma parvum infection and the onset of contractions led to repeat cesarean delivery. The birth weight was 2292 g, and the Apgar scores were 8/8. Both mother and infant had good outcomes. Continuous transabdominal amnioinfusion may have eliminated factors causing intra-amniotic inflammation, thereby prolonging the pregnancy and improving the infant's prognosis.

Vaginal progesterone is associated with decreased group B streptococcus colonisation at term: a retrospective cohort study.

OBJECTIVE: To investigate whether women using intravaginal progesterone suppositories for preterm birth prevention during pregnancy will have lower rates of group B streptococcus (GBS) colonisation at term, compared with women receiving intramuscular 17-alpha-hydroxyprogesterone caproate. DESIGN: This was a retrospective observational cohort study of women who were prescribed a progestogen during their pregnancy for preterm birth prevention, and who delivered at term. SETTING: A tertiary referral hospital in central Ohio. POPULATION: Patients who were prescribed a progestogen during their pregnancy for preterm birth prevention between 2004 and 2017 were included in the study. Patients who delivered at <37 weeks of pregnancy, switched progestogen type during the pregnancy, or had a pessary or cerclage placed were excluded. METHODS: Baseline characteristics were compared using Mann-Whitney U-test or Chi-square test as appropriate. The association between type of progestogen and GBS colonisation was assessed using bivariate and multivariable analyses. MAIN OUTCOME MEASURES: The primary outcome was GBS colonisation. RESULTS: In all, 565 patients were included in the study, of whom 173 received intravaginal progesterone, and 392 17-alpha-hydroxyprogesterone caproate. Patients receiving intravaginal progesterone were less likely to be colonised with GBS (19.7 versus 28.1%). After adjustments for potential confounders were made in a multivariable logistic regression analysis, receiving intravaginal progesterone suppositories (adjusted odds ratio [OR] 0.61, 95% CI 0.39-0.95) was associated with reduced GBS colonisation. CONCLUSIONS: Intravaginal progesterone is associated with a decreased prevalence of rectovaginal GBS colonisation at term. TWEETABLE ABSTRACT: Vaginal progesterone is associated with a lower incidence of rectovaginal GBS colonisation, compared with 17α-hydroxyprogesterone caproate.

Intramuscular 17-hydroxyprogesterone caproate to prevent preterm birth among HIV-infected women in Zambia: study protocol of the IPOP randomized trial.

BACKGROUND: Each year, an estimated 15 million babies are born preterm, a global burden borne disproportionately by families in lower-income countries. Maternal HIV infection increases a woman's risk of delivering prematurely, and antiretroviral therapy (ART) may compound this risk. While prenatal progesterone prophylaxis prevents preterm birth among some high-risk women, it is unknown whether HIV-infected women could benefit from this therapy. We are studying the efficacy of progesterone supplementation to reduce the risk of preterm birth among pregnant women with HIV in Lusaka, Zambia. METHODS: The Improving Pregnancy Outcomes with Progesterone (IPOP) study is a Phase III double-masked, placebo-controlled, randomized trial of intramuscular 17-alpha hydroxprogesterone caproate (17P) to prevent preterm birth in HIV-infected women. A total of 800 women will be recruited prior to 24 weeks of gestation and randomly allocated to 17P or placebo administered by weekly intramuscular injection. The primary outcome will be a composite of live birth prior to 37 completed gestational weeks or stillbirth at any gestational age. Secondary outcomes will include very preterm birth (< 34 weeks), extreme preterm birth (< 28 weeks), small for gestational age (<10th centile), low birth weight (< 2500 g), and neonatal outcomes. In secondary analysis, we will assess whether specific HIV-related covariates, including the timing of maternal ART initiation relative to conception, is associated with progesterone's prophylactic efficacy, if any. DISCUSSION: We hypothesize that weekly prenatal 17P will reduce the risk of HIV-related preterm birth. An inexpensive intervention to prevent preterm birth among pregnant women with HIV could have substantial global public health impact. TRIAL REGISTRATION: NCT03297216 ; September 29, 2017.

Pharmacogenomics of 17-alpha hydroxyprogesterone caproate for recurrent preterm birth: a case-control study.

OBJECTIVE: To compare maternal genotypes between women with and without significant prolongation of pregnancy in the setting of 17-alpha hydroxyprogesterone caproate (17-P) administration for the prevention of recurrent preterm birth (PTB). DESIGN: Case-control. SETTING: Three tertiary-care centres across the USA. POPULATION: Women (n = 99) with ≥ 1 prior singleton spontaneous PTB, receiving 17-P. METHODS: Women were classified as having successful prolongation of pregnancy during the 17-P treated pregnancy, in two ways: (1) Definition A: success/non-success based on difference in gestational age at delivery between 17-P-treated and untreated pregnancies (success: delivered ≥ 3 weeks later with 17-P) and (2) Definition B: success/non-success based on reaching term (success: delivered at term with 17-P). MAIN OUTCOME MEASURES: To assess genetic variation, all women underwent whole exome sequencing. Between-group sequence variation was analysed with the Variant Annotation, Analysis, and Search Tool (VAAST). Genes scored by VAAST with P < 0.05 were then analysed with two online tools: (1) Protein ANalysis THrough Evolutionary Relationships (PANTHER) and (2) Database for Annotation, Visualization, and Integrated Discovery (DAVID). RESULTS: Using Definition A, there were 70 women with successful prolongation and 29 without; 1375 genes scored by VAAST had P < 0.05. Using Definition B, 47 women had successful prolongation and 52 did not; 1039 genes scored by VAAST had P < 0.05. PANTHER revealed key differences in gene ontology pathways. Many genes from definition A were classified as prematurity genes (P = 0.026), and those from definition B as pharmacogenetic genes (P = 0.0018); (P, non-significant after Bonferroni correction). CONCLUSION: A novel analytic approach revealed several genetic differences among women delivering early vs later with 17-P. TWEETABLE ABSTRACT: Several key genetic differences are present in women with recurrent preterm birth despite 17-P treatment.

Inequality and Innovation: Barriers and Facilitators to 17P Administration to Prevent Preterm Birth among Medicaid Participants.

Objectives Strategies to prevent preterm birth are limited. 17 Alpha-Hydroxyprogesterone Caproate (17P) injections have been shown to be effective, but the intervention is under-used. This mixed methods study investigates barriers and facilitators to 17P administration among Medicaid and CHIP participants enrolled in Strong Start for Mothers and Newborns, a federal preterm birth prevention program. Methods Twenty-seven awardees with more than 200 sites in 30 states, the District of Columbia, and Puerto Rico enrolled approximately 46,000 women in Strong Start from 2013 to 2016. Participant data, including data on preterm birth and 17P, was collected for each woman. Intensive interviews (n = 211) conducted with Strong Start program staff and providers (n = 314) included questions about 17P provision. Results Of women whose data included a valid response regarding 17P initiation, 3919 had a prior preterm birth and current singleton pregnancy; 14.95% received 17P. Barriers to 17P administration include late entry to prenatal care, administrative burden of preauthorization, cost risks to providers, limits in scope of practice for non-physician providers, and social barriers among participants. Facilitators for provision include streamlined work flows and the option of home administration. Conclusions for Practice A universal insurance authorization process could mitigate many barriers to 17P use. Providers need continuing education regarding the effectiveness of 17P, and expanding scope of practice for non-physician prenatal care providers would increase access. Targeted program interventions can help to overcome social barriers Medicaid participants face in accessing care. Streamlined work processes and the option of home health services are two effective program-based facilitators for providing 17P to a Medicaid population.

The association among cytochrome P450 3A, progesterone receptor polymorphisms, plasma 17-alpha hydroxyprogesterone caproate concentrations, and spontaneous preterm birth.

BACKGROUND: Infants born <37 weeks' gestation are of public health concern since complications associated with preterm birth are the leading cause of mortality in children <5 years of age and a major cause of morbidity and lifelong disability. The administration of 17-alpha hydroxyprogesterone caproate reduces preterm birth by 33% in women with history of spontaneous preterm birth. We demonstrated previously that plasma concentrations of 17-alpha hydroxyprogesterone caproate vary widely among pregnant women and that women with 17-alpha hydroxyprogesterone caproate plasma concentrations in the lowest quartile had spontaneous preterm birth rates of 40% vs rates of 25% in those women with higher concentrations. Thus, plasma concentrations are an important factor in determining drug efficacy but the reason 17-alpha hydroxyprogesterone caproate plasma concentrations vary so much is unclear. Predominantly, 17-alpha hydroxyprogesterone caproate is metabolized by CYP3A4 and CYP3A5 enzymes. OBJECTIVE: We sought to: (1) determine the relation between 17-alpha hydroxyprogesterone caproate plasma concentrations and single nucleotide polymorphisms in CYP3A4 and CYP3A5; (2) test the association between progesterone receptor single nucleotide polymorphisms and spontaneous preterm birth; and (3) test whether the association between plasma concentrations of 17-alpha hydroxyprogesterone caproate and spontaneous preterm birth varied by progesterone receptor single nucleotide polymorphisms. STUDY DESIGN: In this secondary analysis, we evaluated genetic polymorphism in 268 pregnant women treated with 17-alpha hydroxyprogesterone caproate, who participated in a placebo-controlled trial to evaluate the benefit of omega-3 supplementation in women with history of spontaneous preterm birth. Trough plasma concentrations of 17-alpha hydroxyprogesterone caproate were measured between 25-28 weeks of gestation after a minimum of 5 injections of 17-alpha hydroxyprogesterone caproate. We extracted DNA from maternal blood samples and genotyped the samples using TaqMan (Applied Biosystems, Foster City, CA) single nucleotide polymorphism genotyping assays for the following single nucleotide polymorphisms: CYP3A4*1B, CYP3A4*1G, CYP3A4*22, and CYP3A5*3; and rs578029, rs471767, rs666553, rs503362, and rs500760 for progesteronereceptor. We adjusted for prepregnancy body mass index, race, and treatment group in a multivariable analysis. Differences in the plasma concentrations of 17-alpha hydroxyprogesterone caproate by genotype were evaluated for each CYP single nucleotide polymorphism using general linear models. The association between progesterone receptor single nucleotide polymorphisms and frequency of spontaneous preterm birth was tested using logistic regression. A logistic model also tested interaction between 17-alpha hydroxyprogesterone caproate concentrations with each progesterone receptor single nucleotide polymorphism for the outcome of spontaneous preterm birth. RESULTS: The association between CYP single nucleotide polymorphisms *22, *1G, *1B, and *3 and trough plasma concentrations of 17-alpha hydroxyprogesterone caproate was not statistically significant (P = .68, .44, .08, and .44, respectively). In an adjusted logistic regression model, progesterone receptor single nucleotide polymorphisms rs578029, rs471767, rs666553, rs503362, and rs500760 were not associated with the frequency of spontaneous preterm birth (P = .29, .10, .76, .09, and .43, respectively). Low trough plasma concentrations of 17-alpha hydroxyprogesterone caproate were statistically associated with a higher frequency of spontaneous preterm birth (odds ratio, 0.78; 95% confidence ratio, 0.61-0.99; P = .04 for trend across quartiles), however no significant interaction with the progesterone receptor single nucleotide polymorphisms rs578029, rs471767, rs666553, rs503362, and rs500760 was observed (P = .13, .08, .10, .08, and .13, respectively). CONCLUSION: The frequency of recurrent spontaneous preterm birth appears to be associated with trough 17-alpha hydroxyprogesterone caproate plasma concentrations. However, the wide variation in trough 17-alpha hydroxyprogesterone caproate plasma concentrations is not attributable to polymorphisms in CYP3A4 and CYP3A5 genes. Progesterone receptor polymorphisms do not predict efficacy of 17-alpha hydroxyprogesterone caproate. The limitations of this secondary analysis include that we had a relative small sample size (n = 268) and race was self-reported by the patients.

In an in-vitro model using human fetal membranes, 17-α hydroxyprogesterone caproate is not an optimal progestogen for inhibition of fetal membrane weakening.

BACKGROUND: The progestogen 17-α hydroxyprogesterone caproate (17-OHPC) is 1 of only 2 agents recommended for clinical use in the prevention of spontaneous preterm delivery, and studies of its efficacy have been conflicting. We have developed an in-vitro model to study the fetal membrane weakening process that leads to rupture in preterm premature rupture of the fetal membranes (pPROM). Inflammation/infection associated with tumor necrosis factor-α (TNF-α) induction and decidual bleeding/abruption associated thrombin release are leading causes of preterm premature rupture of the fetal membranes. Both agents (TNF-α and thrombin) cause fetal membrane weakening in the model system. Furthermore, granulocyte-macrophage colony-stimulating factor (GM-CSF) is a critical intermediate for both TNF-α and thrombin-induced fetal membrane weakening. In a previous report, we demonstrated that 3 progestogens, progesterone, 17-alpha hydroxyprogesterone (17-OHP), and medroxyprogesterone acetate (MPA), each inhibit both TNF-α- and thrombin-induced fetal membrane weakening at 2 distinct points of the fetal membrane weakening pathway. Each block both the production of and the downstream action of the critical intermediate granulocyte-macrophage colony-stimulating factor. OBJECTIVE: The objective of the study was to characterize the inhibitory effects of 17-OHPC on TNF-α- and thrombin-induced fetal membrane weakening in vitro. STUDY DESIGN: Full-thickness human fetal membrane fragments from uncomplicated term repeat cesarean deliveries were mounted in 2.5 cm Transwell inserts and cultured with/without 17-alpha hydroxyprogesterone caproate (10-9 to 10-7 M). After 24 hours, medium (supernatant) was removed and replaced with/without the addition of tumor necrosis factor-alpha (20 ng/mL) or thrombin (10 U/mL) or granulocyte-macrophage colony-stimulating factor (200 ng/mL). After 48 hours of culture, medium from the maternal side compartment of the model was assayed for granulocyte-macrophage colony-stimulating factor and the fetal membrane fragments were rupture strength tested. RESULTS: Tumor necrosis factor-alpha and thrombin both weakened fetal membranes (43% and 62%, respectively) and increased granulocyte-macrophage colony-stimulating factor levels (3.7- and 5.9-fold, respectively). Pretreatment with 17-alpha hydroxyprogesterone caproate inhibited both tumor necrosis factor-alpha- and thrombin-induced fetal membrane weakening and concomitantly inhibited the induced increase in granulocyte-macrophage colony-stimulating factor in a concentration-dependent manner. However, contrary to our prior reports regarding progesterone and other progestogens, 17-alpha hydroxyprogesterone caproate did not also inhibit granulocyte-macrophage colony-stimulating factor-induced fetal membrane weakening. CONCLUSION: 17-Alpha hydroxyprogesterone caproate blocks tumor necrosis factor-alpha- and thrombin-induced fetal membrane weakening by inhibiting the production of granulocyte-macrophage colony-stimulating factor. However, 17-alpha hydroxyprogesterone caproate did not also inhibit granulocyte-macrophage colony-stimulating factor-induced weakening. We speculate that progestogens other than 17-alpha hydroxyprogesterone caproate may be more efficacious in preventing preterm premature rupture of the fetal membranes-related spontaneous preterm birth.

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

BACKGROUND: 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. OBJECTIVE: 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. STUDY DESIGN: 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. RESULTS: 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). CONCLUSION: 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.

Racial and ethnic disparities in use of 17-alpha hydroxyprogesterone caproate for prevention of preterm birth.

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.

Does 17-alpha hydroxyprogesterone caproate prevent recurrent preterm birth in obese women?

OBJECTIVE: We sought to determine if maternal weight or body mass index (BMI) modifies the effectiveness of 17-alpha hydroxyprogesterone caproate (17OHP-C). STUDY DESIGN: We performed a secondary analysis of the Maternal-Fetal Medicine Units Network Trial for the Prevention of Recurrent Preterm Delivery by 17-Alpha Hydroxyprogesterone Caproate. Binomial regression models were estimated to determine the relative risk (RR) of preterm birth (PTB) in women randomized to 17OHP-C vs placebo according to BMI category and maternal weight. Adjusted models considered inclusion of potential confounders. RESULTS: In all, 443 women with complete data were included. 17OHP-C is effective in preventing PTB <37 weeks only in women with prepregnancy BMI <30 kg/m(2) (RR, 0.54; 95% confidence interval, 0.43-0.68). Above this BMI threshold there is a nonsignificant trend toward an increased risk of PTB (RR, 1.55; 95% confidence interval, 0.83-2.89) with 17OHP-C treatment. When analyzing by maternal weight, a similar threshold is observed at 165 lb, above which 17OHP-C is no longer effective. CONCLUSION: The effectiveness of 17OHP-C is modified by maternal weight and BMI, and treatment does not appear to reduce the rate of PTB in women who are obese or have a weight >165 lb. This finding may be due to subtherapeutic serum levels in women with increased BMI or weight. Studies of adjusted-dose 17OHP-C in women who are obese or who weigh >165 lb are warranted, and current recommendations regarding the uniform use of 17OHP-C regardless of maternal BMI and weight may deserve reassessment.

17 alpha-hydroxyprogesterone caproate does not prolong pregnancy or reduce the rate of preterm birth in women at high risk for preterm delivery and a short cervix: a randomized controlled trial.

OBJECTIVE: The objective of the study was to evaluate the efficacy of 17 alpha-hydroxyprogesterone caproate (17OHP-C) in prolonging gestation in patients with a short cervix and other risk factors for preterm delivery, such as previous preterm birth, cervical surgery, uterine anomalies, or prenatal diethylstilbestrol (DES) exposure. STUDY DESIGN: This open-label, multicenter, randomized controlled trial included asymptomatic singleton pregnancies from 20(+0) through 31(+6) weeks of gestation with a cervical length less than 25 mm and a history of preterm delivery or cervical surgery or uterine malformation or prenatal DES exposure. Randomization assigned them to receive (or not) 500 mg of intramuscular 17OHP-C weekly until 36 weeks. The primary outcome was time from randomization to delivery. RESULTS: After enrolling 105 patients, an interim analysis demonstrated the lack of efficacy of 17OHP-C in prolonging pregnancy. The study was discontinued because of futility. The groups were similar for maternal age, body mass index, parity, gestational age at inclusion, history of uterine anomalies, DES syndrome, previous preterm delivery or midtrimester abortion, and cervical length at randomization. The enrollment-to-delivery interval did not differ between patients allocated to 17OHP-C (n = 51) and those allocated to the control group (n = 54) (median [interquartile range] time to delivery: 77 [54-103] and 74 [52-99] days, respectively). The rate of preterm delivery less than 37 (45% vs 44%, P > .99), less than 34 (24% vs 30%, P = .51), or less than 32 (14% vs 20%, P = .44) weeks was similar in patients allocated to 17OHP-C and those in the control group. CONCLUSION: 17OHP-C did not prolong pregnancy in women with singleton gestations, a sonographic short cervix, and other risk factors of preterm delivery (prior history, uterine malformations, cervical surgery, or prenatal DES exposure).

A randomised controlled double-blind clinical trial of 17-hydroxyprogesterone caproate for the prevention of preterm birth in twin gestation (PROGESTWIN): evidence for reduced neonatal morbidity.

OBJECTIVE: To determine whether 17 alpha-hydroxyprogesterone caproate (17OHPC) prolongs gestation beyond 37 weeks of gestation (primary outcome) and reduces neonatal morbidity (secondary outcome) in twin pregnancy. DESIGN: Randomised controlled double-blind clinical trial. SETTING: Tertiary-care university medical centre. POPULATION: Unselected women with twin pregnancies. METHODS: Participants received weekly injections of 250 mg 17OHPC (n = 194) or placebo (n = 94), from 16-20 to 36 weeks of gestation. Randomisation was performed using the permuted-block randomisation method. Data were analysed on an intention-to-treat basis. MAIN OUTCOME MEASURE: Preterm birth (PTB) rate before 37 weeks of gestation. RESULTS: There were no significant differences in the average gestational age at delivery, or in the rates of PTB before 37, 32, and 28 weeks of gestation, between the two groups. The proportion of very-low-birthweight neonates (<1500 g) was significantly lower in the 17OHPC group (7.6%) compared with placebo (14.3%) (relative risk, RR 0.5; 95% confidence interval, 95% CI 0.3-0.9; P = 0.01). Progestogen-treated neonates had a significantly lower composite neonatal morbidity (19.1%) compared with placebo (30.9%) (odds ratio, OR 0.53; 95% CI 0.31-0.90; P = 0.02), with significantly lower odds for respiratory distress syndrome (14.4 versus 23.4%; OR 0.55; 95% CI 0.31-0.98; P = 0.04), retinopathy of prematurity (1.1 versus 4.6%; OR 0.21; 95% CI 0.05-0.96; P = 0.04), and culture-confirmed sepsis (3.4 versus 12.8%; OR 0.24; 95% CI 0.10-0.57; P = 0.00). CONCLUSIONS: Intramuscular 17OHPC therapy did not reduce PTB before 37 weeks of gestation in unselected twin pregnancies. Nonetheless, 17OHPC significantly reduced neonatal morbidity parameters and increased birthweight.

Impact of 17-alpha-hydroxyprogesterone caproate on cytochrome P450s in primary cultures of human hepatocytes.

OBJECTIVE: The aim of this study was to examine the effects of 17-alpha-hydroxyprogesterone caproate (17OHP-C) on the activity and expression of several common hepatic cytochrome P450 (CYP) enzymes. STUDY DESIGN: Primary human hepatocytes were pretreated with vehicle or 17OHP-C (0.1 and 1 µmol/L) for 72 hours, then incubated for 1 hour with a cocktail of CYP substrates. The activity of various CYP enzymes was determined by measuring the formation of the metabolites of specific CYP substrates, using liquid chromatography-tandem mass spectrometry. The messenger RNA expression of various CYP enzymes was determined by real-time polymerase chain reaction. RESULTS: In primary cultures of human hepatocytes, 17OHP-C minimally altered the activity or messenger RNA levels of CYP1A2, CYP2C9, CYP2D6, and CYP3A. However, 17OHP-C at 1 µmol/L increased CYP2C19 activity by 2.8-fold (P < .01) and CYP2C19 expression by 2.4-fold (P < .001), compared with vehicle-treated cells. A strong positive correlation between activity and expression of CYP2C19 was also observed (r = 0.9, P < .001). CONCLUSION: The activity and expression of hepatic CYP2C19 was significantly increased by 17OHP-C in primary cultures of human hepatocytes. This suggests that exposure to medications that are metabolized by CYP2C19 may be decreased in pregnant patients receiving 17OHP-C. Metabolism of substrates of CYP1A2, CYP2C9, CYP2D6, and CYP3A are not expected to be altered in patients receiving 17OHP-C.

Challenges in Using Progestin to Prevent Singleton Preterm Births: Current Knowledge and Clinical Advice.

Preterm birth is the leading cause of infant morbidity and mortality in children younger than 5 years old and accounts for approximately 35% of newborn deaths worldwide. The use of progestogen therapy for prevention of preterm birth has been one of the most controversial topics in modern obstetrics. Progestogens can be classified as natural or synthetic. Progesterone is a natural progestogen while progestins such as 17-alpha-hydroxyprogesterone caproate (17OHP-C) are synthetic steroid hormones. Evidence supporting the use of progestogens varies by formulation and populations studied. After more than a decade, the US Food and Drug Administration has withdrawn accelerated approval of 17OHP-C for the prevention of recurrent preterm birth in pregnant individuals with a singleton gestation. With this decision, there is no current FDA-approved treatment for prevention of spontaneous preterm birth. In this review, we provide a historical context behind the rise and fall of 17OHP-C clinical application, highlight the challenges behind the data supporting progestogen use, and offer suggestions on how to make an impact on preterm birth moving forward.

What now? A critical evaluation of over 20 years of clinical and research experience with 17-alpha hydroxyprogesterone caproate for recurrent preterm birth prevention.

Spontaneous preterm birth is multifactorial, and underlying etiologies remain incompletely understood. Supplementation with progestogens, including 17-alpha hydroxyprogesterone caproate has been a mainstay of prematurity prevention strategies in the United States in the last 2 decades. Following a recent negative confirmatory trial, 17-alpha hydroxyprogesterone caproate was withdrawn from the US market and is currently available only through clinical research studies. This expert review summarized clinical and research data regarding the use of 17-alpha hydroxyprogesterone caproate in the United States from 2003 to 2023 for recurrent prematurity prevention. In 17-alpha hydroxyprogesterone caproate. The history of the use, mechanisms of action, clinical trial results, and efficacy by clinical and biologic criteria of 17-alpha hydroxyprogesterone caproate are presented. We report that disparate findings and conclusions between similarly designed rigorous studies may reflect differences in a priori risk and population incidence and extreme care should be taken in interpreting the studies and making decisions regarding efficacy of 17-alpha hydroxyprogesterone caproate for the prevention of preterm birth. The likelihood of improved obstetrical outcomes after receiving 17-alpha hydroxyprogesterone caproate may vary by clinical factors (eg, body mass index), plasma drug concentrations, and genetic factors, although the identification of individuals most likely to benefit remains imperfect. It is crucial for the medical community to recognize the importance of preserving the decades-long efforts invested in preventing recurrent preterm birth in the United States. Moreover, it is important that we thoroughly and thoughtfully evaluate 17-alpha hydroxyprogesterone caproate as a promising contender for future well-executed prematurity studies.