17-α Hydroxyprogesterone Caproate for the Prevention of Recurrent Preterm Birth: One Size May Not Fit All

Reassessing Preterm Birth Prevention After the Withdrawal of 17-α Hydroxyprogesterone Caproate

The U.S. Food and Drug Administration has recently withdrawn approval for 17-α hydroxyprogesterone caproate for prevention of recurrent preterm birth, and recent studies have called into question benefits of the pessary in the setting of a short cervix. Obstetric health care professionals are once again left with limited remaining options for preterm birth prevention. This narrative review summarizes the best current evidence on the use of vaginal progesterone, low-dose aspirin, and cerclage for the prevention of preterm birth; attempts to distill possible lessons learned from studies of progesterone and pessary, as well as their implementation into practice; and highlights areas where inroads into preterm birth prevention may be possible outside of the progesterone-aspirin-cerclage paradigm.

Cervical pessary to prevent preterm birth in asymptomatic high-risk women: a systematic review and meta-analysis

BACKGROUND

Randomized controlled trials that have assessed the efficacy of cervical pessary to prevent preterm birth in asymptomatic high-risk women have reported conflicting results.

OBJECTIVE

To evaluate the efficacy and safety of cervical pessary to prevent preterm birth and adverse perinatal outcomes in asymptomatic high-risk women.

DATA SOURCES

MEDLINE, EMBASE, POPLINE, CINAHL, and LILACS (from their inception to October 31, 2019), Cochrane databases, Google Scholar, bibliographies, and conference proceedings.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials that compared cervical pessary with standard care (no pessary) or alternative interventions in asymptomatic women at high risk for preterm birth.

STUDY APPRAISAL AND SYNTHESIS METHODS

The systematic review was conducted according to the Cochrane Handbook guidelines. The primary outcome was spontaneous preterm birth <34 weeks of gestation. Secondary outcomes included adverse pregnancy, maternal, and perinatal outcomes. Pooled relative risks with 95% confidence intervals were calculated. Quality of evidence was assessed using the GRADE methodology.

RESULTS

Twelve studies (4687 women and 7167 fetuses/infants) met the inclusion criteria: 8 evaluated pessary vs no pessary in women with a short cervix, 2 assessed pessary vs no pessary in unselected multiple gestations, and 2 compared pessary vs vaginal progesterone in women with a short cervix. There were no significant differences between the pessary and no pessary groups in the risk of spontaneous preterm birth <34 weeks of gestation among singleton gestations with a cervical length ≤25 mm (relative risk, 0.80; 95% confidence interval, 0.43-1.49; 6 trials, 1982 women; low-quality evidence), unselected twin gestations (relative risk, 1.05; 95% confidence interval, 0.79-1.41; 1 trial, 1177 women; moderate-quality evidence), twin gestations with a cervical length <38 mm (relative risk, 0.75; 95% confidence interval, 0.41-1.36; 3 trials, 1128 women; low-quality evidence), and twin gestations with a cervical length ≤25 mm (relative risk; 0.72, 95% confidence interval, 0.25-2.06; 2 trials, 348 women; low-quality evidence). Overall, no significant differences were observed between the pessary and no pessary groups in preterm birth <37, <32, and <28 weeks of gestation, and most adverse pregnancy, maternal, and perinatal outcomes (low- to moderate-quality evidence for most outcomes). There were no significant differences in the risk of spontaneous preterm birth <34 weeks of gestation between pessary and vaginal progesterone in singleton gestations with a cervical length ≤25 mm (relative risk, 0.99; 95% confidence interval, 0.54-1.83; 1 trial, 246 women; low-quality evidence) and twin gestations with a cervical length <38 mm (relative risk, 0.73; 95% confidence interval, 0.46-1.18; 1 trial, 297 women; very low-quality evidence). Vaginal discharge was significantly more frequent in the pessary group than in the no pessary and vaginal progesterone groups (relative risks, ∼2.20; high-quality evidence).

CONCLUSION

Current evidence does not support the use of cervical pessary to prevent preterm birth or to improve perinatal outcomes in singleton or twin gestations with a short cervix and in unselected twin gestations.

Progestogen for treating threatened miscarriage

BACKGROUND

Miscarriage is a common complication encountered during pregnancy. It is defined as spontaneous pregnancy loss before 20 weeks' gestation. Progesterone's physiological role is to prepare the uterus for the implantation of the embryo, enhance uterine quiescence and suppress uterine contractions, hence, it may play a role in preventing rejection of the embryo. Inadequate secretion of progesterone in early pregnancy has been linked to the aetiology of miscarriage and progesterone supplementation has been used as a treatment for threatened miscarriage to prevent spontaneous pregnancy loss. This update of the Cochrane Review first published in 2007, and previously updated in 2011, investigates the evidence base for this practice.

OBJECTIVES

To determine the efficacy and the safety of progestogens in the treatment of threatened miscarriage.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) (8 August 2017) and reference lists of retrieved trials.

SELECTION CRITERIA

Randomised, quasi-randomised or cluster-randomised controlled trials, that compared progestogen with placebo, no treatment or any other treatment for the treatment of threatened miscarriage in women carrying singleton pregnancy.

DATA COLLECTION AND ANALYSIS

At least two review authors assessed the trials for inclusion in the review, assessed trial quality and extracted the data and graded the body of evidence.

MAIN RESULTS

We included seven trials (involving 696 participants) in this update of the review. The included trials were conducted in different countries, covering the full spectrum of the World Bank's economic classification, which enhances the applicability of evidence drawn from this review. Two trials were conducted in Germany and Italy which are high-income countries, while four trials were conducted in upper-middle income countries; two in Iran, one in Malaysia and the fourth in Turkey, and the seventh trial was conducted in Jordan, which is a lower-middle income country. In six trials all the participants met the inclusion criteria and in the seventh study, we included in the meta-analysis only the subgroup of participants who met the inclusion criteria. We assessed the body of evidence for the main outcomes using the GRADE tool and the quality of the evidence ranged from very low to moderate. Downgrading of evidence was based on the high risk of bias in six of the seven included trials and a small number of events and wide confidence intervals for some outcomes.Treatment of miscarriage with progestogens compared to placebo or no treatment probably reduces the risk of miscarriage; (risk ratio (RR) 0.64, 95% confidence interval (CI) 0.47 to 0.87; 7 trials; 696 women; moderate-quality evidence). Treatment with oral progestogen compared to no treatment also probably reduces the miscarriage rate (RR 0.57, 95% CI 0.38 to 0.85; 3 trials; 408 women; moderate-quality evidence). However treatment with vaginal progesterone compared to placebo, probably has little or no effect in reducing the miscarriage rate (RR 0.75, 95% CI 0.47 to 1.21; 4 trials; 288 women; moderate-quality evidence). The subgroup interaction test indicated no difference according to route of administration between the oral and vaginal subgroups of progesterone.Treatment of preterm birth with the use of progestogens compared to placebo or no treatment may have little or no effect in reducing the rate of preterm birth (RR 0.86, 95% CI 0.52 to 1.44; 5 trials; 588 women; low-quality evidence).We are uncertain if treatment of threatened miscarriage with progestogens compared to placebo or no treatment has any effect on the rate of congenital abnormalities because the quality of the evidence is very low (RR 0.70, 95% CI 0.10 to 4.82; 2 trials; 337 infants; very-low quality evidence).

AUTHORS' CONCLUSIONS

The results of this Cochrane Review suggest that progestogens are probably effective in the treatment of threatened miscarriage but may have little or no effect in the rate of preterm birth. The evidence on congenital abnormalities is uncertain, because the quality of the evidence for this outcome was based on only two small trials with very few events and was found to be of very low quality.

17OHP-C in patients with spontaneous preterm labor and intact membranes: is there an effect according to the presence of intra-amniotic inflammation?

PROBLEM

It is not known whether 17-alpha-hydroxyprogesterone caproate (17OHP-C) is effective for preventing preterm delivery with an episode of preterm labor (PTL) with or without intra-amniotic inflammation/infection.

METHODS OF STUDY

This was a retrospective cohort study. One hundred and seven PTL patients were selected and divided into a 17OHP-C group (use of 17OHP-C: n = 53) and a no-treatment group (no use of 17OHP-C: n = 54). Moreover, the patients were divided into three subgroups (subgroup A: without intra-amniotic inflammation, B: with mild intra-amniotic inflammation, and C: with severe intra-amniotic inflammation) according to their level of amniotic interleukin (IL)-8, and perinatal prognosis was analyzed.

RESULTS

Interval from admission to delivery (days) in the 17OHP-C group (76 [13-126], n = 34) was significantly longer than that in the no-treatment group (50 [8-104], n = 33; P = .012) in subgroup B. In cases without intra-amniotic microbes in subgroup B, a significant prolongation of gestational days was associated with the 17OHP-C group (79 [13-126], n = 25) compared with the no-treatment group (50 [8-104], n = 29; P = .029). However, there were no significant differences in subgroups A or C.

CONCLUSION

17OHP-C could prolong gestational period in limited PTL cases with sterile mild intra-amniotic inflammation.

Screening for spontaneous preterm birth and resultant therapies to reduce neonatal morbidity and mortality: A review

Despite considerable effort aimed at decreasing the incidence of spontaneous preterm birth, it remains the leading cause of perinatal morbidity and mortality. Screening strategies are imperfect. Approaches used to identify women considered by historical factors to be low risk for preterm delivery (generally considered to be women with singleton pregnancies without a history of a previous preterm birth) as well as those at high risk for preterm birth (those with a previous preterm birth, short cervix, or multiple gestation) continue to evolve. Herein, we review the current evidence and approaches to screening women for preterm birth, and examine future directions for clinical practice. Further research is necessary to better identify at-risk women and provide evidence-based management.

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.