The effect of 17-alpha hydroxyprogesterone caproate on the risk of gestational diabetes in singleton or twin pregnancies

Progesterone, cerclage, pessary, or acetylsalicylic acid for prevention of preterm birth in singleton and multifetal pregnancies - A systematic review and meta-analyses

Background

Preterm birth is the leading cause of childhood mortality and morbidity. We aimed to provide a comprehensive systematic review on randomized controlled trials (RCTs) on progesterone, cerclage, pessary, and acetylsalicylic acid (ASA) to prevent preterm birth in asymptomatic women with singleton pregnancies defined as risk of preterm birth and multifetal pregnancies.

Methods

Six databases (including PubMed, Embase, Medline, the Cochrane Library) were searched up to February 2022. RCTs published in English or Scandinavian languages were included through a consensus process. Abstracts and duplicates were excluded. The trials were critically appraised by pairs of reviewers. The Cochrane risk-of-bias tool was used for risk of bias assessment. Predefined outcomes including preterm birth, perinatal/neonatal/maternal mortality and morbidity, were pooled in meta-analyses using RevMan 5.4, stratified for high and low risk of bias trials. The certainty of evidence was assessed using the GRADE approach. The systematic review followed the PRISMA guideline.

Results

The search identified 2,309 articles, of which 87 were included in the assessment: 71 original RCTs and 16 secondary publications with 23,886 women and 32,893 offspring. Conclusions were based solely on trials with low risk of bias (n = 50).Singleton pregnancies: Progesterone compared with placebo, reduced the risk of preterm birth <37 gestational weeks: 26.8% vs. 30.2% (Risk Ratio [RR] 0.82 [95% Confidence Interval [CI] 0.71 to 0.95]) (high certainty of evidence, 14 trials) thereby reducing neonatal mortality and respiratory distress syndrome. Cerclage probably reduced the risk of preterm birth <37 gestational weeks: 29.0% vs. 37.6% (RR 0.78 [95% CI 0.69 to 0.88]) (moderate certainty of evidence, four open trials). In addition, perinatal mortality may be reduced by cerclage. Pessary did not demonstrate any overall effect. ASA did not affect any outcome, but evidence was based on one underpowered study.Multifetal pregnancies: The effect of progesterone, cerclage, or pessary was minimal, if any. No study supported improved long-term outcome of the children.

Conclusion

Progesterone and probably also cerclage have a protective effect against preterm birth in asymptomatic women with a singleton pregnancy at risk of preterm birth. Further trials of ASA are needed. Prevention of preterm birth requires screening programs to identify women at risk of preterm birth.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021234946].

Utilization, adherence, and outcomes of 17-alpha hydroxyprogesterone caproate for recurrent spontaneous preterm birth prevention

OBJECTIVE

To describe the use of and adherence to 17-alpha hydroxyprogesterone caproate (17-OHPC), explore factors associated with its utilization and adherence, and to investigate the outcomes of 17-OHPC in a real-world setting.

METHODS

The Decision Resources Group (DRG) database (1 January 2012-31 December 2017) was used to identify women with diagnosis of "history of preterm labor", aged 16-50 years old, had a singleton gestation, were continuously enrolled for at least 6 months and 9 months before and after the index date, respectively, and had a delivery outcome recorded. Adequate adherence was defined and compared using two approaches: (1) patients receiving at least 10 injections of 17-OHPC; (2) number of received injections/eligible number of injections ≥0.7. The outcome of 17-OHPC was evaluated by the incidence rate of preterm birth (PTB). Bivariate tests compared patients' characteristics with their use of and adherence to 17-OHPC, and examined the associations between 17-OHPC utilization and incidence of diabetes or hypertension. Stepwise logistic regression was conducted to assess the effect of adherence on the delivery outcome.

RESULTS

Of 28,339 patients meeting study criteria, 2585 (9.1%) had ≥1 claim for 17-OHPC. An increasing trend of utilization was observed from 2012 to 2017 (7.6-13.1%). The utilization rate was highest in the Southwest US (13.8%) (p < .001). Commercial insurance patients (9.6%) were more likely to use 17-OHPC than Medicaid patients (7.9%) (p < .001). Patients with higher Charlson Comorbidity Index (CCI) scores were less likely to use 17-OHPC. Of women prescribed 17-OHPC, 792 (30.6%) and 424 (16.4%) were adherent using two definitions, respectively. No difference in PTB rate was observed between adherers and non-adherers (definition 1: aOR = 0.97, 95% CI = 0.81-1.16; definition 2: aOR = 1.18, 95% CI = 0.95-1.48). No association was found between 17-OHPC and incidence of diabetes (p = .96); however, use of 17-OHPC was associated with a lower incidence rate of hypertension (p = .002).

CONCLUSIONS

17-OHPC utilization and adherence rates remain low. Insurance type and geographic region were associated with both utilization and adherence. There was no association between 17-OHPC adherence and effectiveness. More evidence is needed to determine if the use of 17-OHPC is advantageous in a sub-group of patients.

Safety review of hydroxyprogesterone caproate in women with a history of spontaneous preterm birth

17-alpha-hydroxyprogesterone caproate (17P) has been in use for prevention of recurrent preterm birth since 2003 when the Meis trial was published. A requirement for Food and Drug Administration approval of 17P was a confirmatory trial, called "PROLONG", which was recently completed, but did not replicate the efficacy demonstrated in the Meis trial. This review analyzes the safety data from each trial, as well as integrated data from the two trials. The relative risks (95% CI) with 17P versus placebo in the integrated dataset were 0.66 (0.25-1.78) for miscarriage, 1.83 (0.68-4.91) for stillbirth, and 0.86 (0.53-1.41) for all fetal and neonatal death. The rate of gestational diabetes in the integrated dataset was 3.6% for 17P vs. 3.8% for placebo. Similar findings with low and comparable rates between 17P and placebo were also found for other adverse events. The integrated safety data demonstrate a favorable safety profile that was comparable to placebo.

Vaginal Progesterone Has No Diabetogenic Potential in Twin Pregnancies: A Retrospective Case-Control Study on 1686 Pregnancies

Background: In this study, we aimed to investigate the incidence of gestational diabetes mellitus (GDM) in women who carried twin pregnancies and received vaginal progesterone. Methods: In this retrospective cohort study, 203 out of 1686 women with twin pregnancies received natural progesterone (200 mg/day between gestational weeks 16 + 0 and 36 + 0) vaginally for ≥ 4 weeks. The control group consisted of 1483 women with twin pregnancies without progesterone administration. Pearson’s Chi squared test, Fisher’s exact test, and Student’s t-test was used to compare differences between the control and the progesterone-treated groups. A multivariate binary logistic regression was performed to assess relative independent associations on the dependent outcome of GDM incidence. Results: Vaginal progesterone treatment in twin pregnancies had no significant influence on developing GDM (p = 0.662). Higher pre-pregnancy BMI (OR 1.1; p < 0.001), GDM in previous pregnancy (OR 6.0; p < 0.001), and smoking during pregnancy (OR 1.6; p = 0.014) posed an increased risk for developing GDM. Conclusion: In twin pregnancies, the use of vaginal progesterone for the prevention of recurrent preterm delivery was not associated with an increased risk of GDM.

Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy

BACKGROUND

Multiple pregnancy is a strong risk factor for preterm birth, and more than 50% of women with a twin pregnancy will give birth prior to 37 weeks' gestation. Infants born preterm are recognised to be at increased risk of many adverse health outcomes, contributing to more than half of overall perinatal mortality. Progesterone is produced naturally in the body and has a role in maintaining pregnancy, although it is not clear whether administering progestogens to women with multiple pregnancy at high risk of early birth is effective and safe. Since publication of this new review in Issue 10, 2017, we have now moved one study (El-Refaie 2016) from included to studies awaiting classification, pending clarification about the study data.

OBJECTIVES

To assess the benefits and harms of progesterone administration for the prevention of preterm birth in women with a multiple pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (1 November 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials examining the administration of a progestogen by any route for the prevention of preterm birth in women with multiple pregnancy. We did not include quasi-randomised or cross-over studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed reports identified by the search for eligibility, extracted data, assessed risk of bias and graded the quality of the evidence.

MAIN RESULTS

We included 16 trials, which all compared either vaginal or intramuscular (IM) progesterone with a placebo or no treatment, and involved a total of 4548 women. The risk of bias for the majority of included studies was low, with the exception of three studies that had inadequate blinding, or significant loss to follow-up or both, or were not reported well enough for us to make a judgement. We graded the evidence low to high quality, with downgrading for statistical heterogeneity, design limitations in some of the studies contributing data, and imprecision of the effect estimate. 1 IM progesterone versus no treatment or placebo More women delivered at less than 34 weeks' gestation in the IM progesterone group compared with placebo (risk ratio (RR) 1.54, 95% confidence interval (CI) 1.06 to 2.26; women = 399; studies = 2; low-quality evidence). Although the incidence of perinatal death in the progesterone group was higher, there was considerable uncertainty around the effect estimate and high heterogeneity between studies (average RR 1.45, 95% CI 0.60 to 3.51; infants = 3089; studies = 6; I2 = 71%; low-quality evidence). No studies reported maternal mortality or major neurodevelopmental disability at childhood follow-up. There were no clear group differences found in any of the other maternal or infant outcomes (preterm birth less than 37 weeks (RR 1.05, 95% CI 0.98 to 1.13; women = 2010; studies = 5; high-quality evidence); preterm birth less than 28 weeks (RR 1.08, 95% CI 0.75 to 1.55; women = 1920; studies = 5; moderate-quality evidence); infant birthweight less than 2500 g (RR 0.99, 95% CI 0.90 to 1.08; infants = 4071; studies = 5; I2 = 76%, moderate-quality evidence)). No childhood outcomes were reported in the trials. 2 Vaginal progesterone versus no treatment or placebo by dose There were no clear group differences in incidence of preterm birth before 34 weeks (average RR 0.90, 95% CI 0.66 to 1.23; women = 1503; studies = 5; I2 = 36%; low-quality evidence). Although fewer births before 34 weeks appeared to occur in the progesterone group, the CIs crossed the line of no effect. Incidence of perinatal death was higher in the progesterone group, although there was considerable uncertainty in the effect estimate and the quality of the evidence was low for this outcome (RR 1.23, 95% CI 0.74 to 2.06; infants = 2287; studies = 3; low-quality evidence). No studies reported maternal mortality or major neurodevelopmental disability at childhood follow-up. There were no clear group differences found in any of the other maternal or infant outcomes (preterm birth less than 37 weeks (average RR 0.97, 95% CI 0.89 to 1.06; women = 1597; studies = 6; moderate-quality evidence); preterm birth less than 28 weeks (RR 1.53, 95% CI 0.79 to 2.97; women = 1345; studies = 3; low-quality evidence); infant birthweight less than 2500 g (average RR 0.95, 95% CI 0.84 to 1.07; infants = 2640; studies = 3; I2 = 66%, moderate-quality evidence)). No childhood outcomes were reported in the trials. For secondary outcomes, there were no clear group differences found in any of the other maternal outcomes except for caesarean section, where women who received vaginal progesterone did not have as many caesarean sections as those in the placebo group, although the difference between groups was not large (8%) (RR 0.92, 95% CI 0.86 to 0.98; women = 1919; studies = 5; I2 = 0%). There were no clear group differences found in any of the infant outcomes except for mechanical ventilation, which was required by fewer infants whose mothers had received the vaginal progesterone (RR 0.70, 95% CI 0.52 to 0.94; infants = 2695; studies = 4).

AUTHORS' CONCLUSIONS

Overall, for women with a multiple pregnancy, the administration of progesterone (either IM or vaginal) does not appear to be associated with a reduction in risk of preterm birth or improved neonatal outcomes. Future research could focus on a comprehensive individual participant data meta-analysis including all of the available data relating to both IM and vaginal progesterone administration in women with a multiple pregnancy, before considering the need to conduct trials in subgroups of high-risk women (for example, women with a multiple pregnancy and a short cervical length identified on ultrasound).

Progestogens for the prevention of preterm birth and risk of developing gestational diabetes mellitus: a meta-analysis

BACKGROUND

Several articles have implied that progestogen supplementation during pregnancy to reduce the risk of preterm birth may increase the risk for developing gestational diabetes mellitus.

OBJECTIVE

The purpose of the present meta-analysis was to accumulate existing evidence concerning this correlation.

DATA SOURCES

We searched Medline (1966-2019), Scopus (2004-2019), Clinicaltrials.gov (2008-2019), EMBASE (1980-2019), Cochrane Central Register of Controlled Trials CENTRAL (1999-2019), and Google Scholar (2004-2019) databases.

STUDY ELIGIBILITY CRITERIA

Randomized trials and observational studies were considered eligible for inclusion in the present meta-analysis. To minimize the possibility of article losses, we avoided language, country, and date restrictions.

STUDY APPRAISAL AND SYNTHESIS METHODS

The methodological quality of included studies was evaluated with the Cochrane risk of bias and the Risk Of Bias In Non-Randomized Studies of Interventions (ROBINS-I) tool. Meta-analysis was performed with the RevMan 5.3 and secondary analysis with the Open Meta-Analyst software. Trial sequential analysis was conducted with the trial sequential analysis program.

RESULTS

Overall, 11 studies were included in the present meta-analysis that recruited 8085 women. The meta-analysis revealed that women who received 17-alpha hydroxyprogesterone caproate had increased the risk of developing gestational diabetes mellitus (risk ratio, 1.73, 95% confidence interval, 1.32-2.28), whereas women who received vaginal progesterone had a decreased risk, although the effect did not reach statistical significance because of the unstable estimate of confidence intervals (risk ratio, 0.82, 95% confidence interval, 0.50-1.12). Meta-regression analysis indicated that neither the methodological rationale for investigating the prevalence of gestational diabetes mellitus (incidence investigated as primary or secondary outcome) (coefficient of covariance, -0.36, 95% confidence interval, -0.85 to 0.13, P = .154) nor the type of investigated study (randomized controlled trial/observational) (coefficient of covariance -0.361, 95% confidence interval, -1.049 to 0.327, P = .304) significantly altered the results of the primary analysis. Trial sequential analysis suggested that the meta-analysis concerning the correlation of 17-alpha hydroxyprogesterone caproate was of adequate power to reach firm conclusions, whereas this was not confirmed in the case of vaginal progesterone.

CONCLUSION

The results of the present meta-analysis clearly indicate that women who receive supplemental 17-alpha hydroxyprogesterone caproate for the prevention of preterm birth have an increased risk of developing gestational diabetes mellitus. On the other hand, evidence concerning women treated with vaginal progesterone remains inconclusive.

17α-Hydroxyprogesterone Caproate and the Risk of Glucose Intolerance in Pregnancy: A Systematic Review and Meta-analysis

OBJECTIVE

To evaluate whether 17α-hydroxyprogesterone caproate use in preventing preterm birth increases the risk of gestational diabetes mellitus (GDM).

DATA SOURCES

Electronic databases (MEDLINE, Scopus, ClinicalTrials.gov, PROSPERO, EMBASE, Scielo and the Cochrane Central Register of Controlled Trials) were searched for studies published before October 2018. Keywords included "gestational diabetes," "preterm birth," "pregnancy," and "17-hydroxyprogesterone caproate."

METHODS OF STUDY SELECTION

Studies comparing 17α-hydroxyprogesterone caproate with unexposed control groups in women with singleton gestation and a history of a prior spontaneous preterm birth were included. The primary outcome was the development of GDM. Secondary outcomes included abnormal 1-hour, 50-g glucose screen results and mean venous blood glucose levels. Summary estimates were reported as mean differences and 95% CI for continuous variables or relative risk (RR) with 95% CI for dichotomous outcomes. Meta-analysis was performed using the random effects model of DerSimonian and Laird.

TABULATION, INTEGRATION AND RESULTS

Six studies, four of which were cohort studies, met inclusion criteria and were included in the final meta-analysis. Of the 5,053 women, 1,538 (30.4%) received 17α-hydroxyprogesterone caproate and 3,515 (69.6%) were in unexposed control groups. The overall rate of GDM in women exposed to 17α-hydroxyprogesterone caproate was 10.9% vs 6.1% in women who were not exposed (RR 1.77, 95% CI 1.22-2.55). After exclusion of the cohort studies, the summary estimate of effect was nonsignificant among women who had been randomly allocated to 17α-hydroxyprogesterone caproate (RR 1.21, 95% CI 0.63-2.36).

CONCLUSION

Women with singleton gestations receiving weekly 17α-hydroxyprogesterone caproate for recurrent preterm birth prevention had a significantly higher incidence of abnormal glucose test results and GDM compared with those in unexposed control groups, a finding that did not hold among women who had been randomly allocated to 17α-hydroxyprogesterone caproate.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, CRD42016041694.

Is vaginal progesterone treatment associated with the development of gestational diabetes? A retrospective case-control study

PURPOSE

To determine the incidence of gestational diabetes mellitus (GDM) in pregnant women who received vaginal progesterone due to short cervical length or to prevent recurrent preterm birth.

METHODS

In this retrospective study, we included 190 women with singleton pregnancies at risk for preterm birth who received vaginal natural progesterone (200 mg daily between gestational weeks 16 + 0 and 36 + 0) for a minimum of 4 weeks and delivered > 28 weeks. The control group consisted of 242 age- and body mass index (BMI)-matched patients without progesterone administration. Data were acquired from a database containing prospectively collected information. Patients with pre-existing diabetes, and conception after in vitro fertilisation procedure were excluded.

RESULTS

The incidence of GDM did not differ significantly between the progesterone-treated and the control group (14.7% vs. 16.9%, respectively; p = 0.597). In a binary regression model, patients with higher pre-pregnancy BMI (OR 1.1; p = 0.006), and those with a family history of diabetes had a higher risk for GDM development (OR 1.8; p = 0.040), whereas vaginal progesterone treatment had no significant influence (p = 0.580).

CONCLUSION

The use of vaginal progesterone for the prevention of recurrent preterm delivery and in women with a short cervix does not seem to be associated with an increased risk of GDM.

Genetic variants in sex hormone pathways and the risk of type 2 diabetes among African American, Hispanic American, and European American postmenopausal women in the US

BACKGROUND

Sex hormones are implicated in the development of diabetes. However, whether genetic variations in sex hormone pathways (SHPs) contribute to the risk of type 2 diabetes mellitus (T2DM) remains to be determined. This study investigated associations between genetic variations in all candidate genes in SHPs and T2DM risk among a cohort of women participating in the Women's Health Initiative (WHI).

METHODS

Single nucleotide polymorphisms (SNPs) located within 30 kb upstream and downstream of SHP genes were comprehensively examined in 8180 African American, 3498 Hispanic American, and 3147 European American women in the WHI. In addition, whether significant SNPs would be replicated in independent populations was examined.

RESULTS

After adjusting for age, region, and ancestry estimates and correcting for multiple testing, seven SNPs were significantly associated with the risk of T2DM among Hispanic American women were identified in the progesterone receptor (PGR) gene, with rs948516 showing the greatest significance (odds ratio 0.67; 95% confidence interval 0.57-0.78; P = 8.8 × 10^-7 ; false discovery rate, Q = 7.8 × 10^-4 ). These findings were not replicated in other ethnic groups in the WHI or in sex-combined analyses in replication studies.

CONCLUSION

Significant signals were identified implicating the PGR gene in T2DM development in Hispanic American women in the WHI, which are consistent with genome-wide association studies findings linking PGR to glucose homeostasis. Nevertheless, the PGR SNPs-T2DM association was not statistically significant in other ethnic populations. Further studies, especially sex-specific analyses, are needed to confirm the findings and clarify the role of SHPs in T2DM.

Predictive factors of gestational diabetes in pregnancies following assisted reproductive technology: a nested case-control study

PURPOSE

To evaluate predictive factors for gestational diabetes mellitus (GDM) in singleton pregnancy following assisted reproductive technology (ART).

METHODS

This nested case-control study was performed during October 2016-June 2017. Pregnant women who conceived following ART procedures referred to infertility clinic were selected and categorized into GDM and non-GDM based on ADA/IAPDSG criteria. The study variables including age, educational status, first-degree family history of chronic diseases, systolic and diastolic blood pressure, previous obstetric and perinatal outcomes, infertility history, and ART cycle characteristics were collected from medical records. Prediction model to develop GDM was employed by binary logistic regression analysis after adjustment for age and body mass index, family history of diabetes, and gravidity.

RESULTS

In total, 270 women with singleton pregnancies (consisted of 135 GDM and 135 non-GDM women) conceived were studied. According to the final model, significant predictors of GDM were history of polycystic ovarian syndrome (PCOS), previous ovarian hyper-stimulation syndrome (OHSS) risk and progesterone injections. Administration of injectable progesterone during the first 10-12 weeks of pregnancy was associated with an approximately twofold increased risk of developing GDM [odds ratio (OR) 2.28, 95% confidence interval (CI) 1.27-4.09)] compared to vaginal progesterone. In addition, the regression analysis revealed that previous OHSS risk (OR 2.40, 95% CI 1.34-4.31) and history of PCOS (OR 2.76, 95% CI 1.26-6.06) were other most important predictors of GDM.

CONCLUSIONS

The route of progesterone administration, previous OHSS risk and history of PCOS seem to be putative risk factors for GDM in women conceived by ART.

17-alpha hydroxyprogesterone caproate for preterm birth prevention: Where have we been, how did we get here, and where are we going?

Prematurity is a major public health problem in the United States and worldwide. Women with a history of a previous preterm birth are at high risk for recurrence. Progesterone is a key hormone involved in pregnancy maintenance. In general, progesterone is thought to maintain pregnancy through several closely linked mechanisms: (1) promotion of uterine quiescence, (2) inhibition of pro-inflammatory cells, and (3) immunosuppressive action. 17-Alpha hydroxyprogesterone caproate is currently the only medication approved to prevent recurrent preterm birth. The purpose of this review is to discuss the history of 17-alpha hydroxyprogesterone caproate use for recurrent preterm birth prevention, the rationale behind 17-alpha hydroxyprogesterone caproate administration, and current evidence-based indications for 17-alpha hydroxyprogesterone caproate use.

Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy

BACKGROUND

Multiple pregnancy is a strong risk factor for preterm birth, and more than 50% of women with a twin pregnancy will give birth prior to 37 weeks' gestation. Infants born preterm are recognised to be at increased risk of many adverse health outcomes, contributing to more than half of overall perinatal mortality. Progesterone is produced naturally in the body and has a role in maintaining pregnancy, although it is not clear whether administering progestogens to women with multiple pregnancy at high risk of early birth is effective and safe.

OBJECTIVES

To assess the benefits and harms of progesterone administration for the prevention of preterm birth in women with a multiple pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (1 November 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials examining the administration of a progestogen by any route for the prevention of preterm birth in women with multiple pregnancy. We did not include quasi-randomised or cross-over studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed reports identified by the search for eligibility, extracted data, assessed risk of bias and graded the quality of the evidence.

MAIN RESULTS

We included 17 trials, which all compared either vaginal or intramuscular (IM) progesterone with a placebo or no treatment, and involved a total of 4773 women. The risk of bias for the majority of included studies was low, with the exception of four studies that had inadequate blinding, or significant loss to follow-up or both, or were not reported well enough for us to make a judgement. We graded the evidence low to high quality, with downgrading for statistical heterogeneity, design limitations in some of the studies contributing data, and imprecision of the effect estimate. 1 IM progesterone versus no treatment or placeboMore women delivered at less than 34 weeks' gestation in the IM progesterone group compared with placebo (risk ratio (RR) 1.54, 95% confidence interval (CI) 1.06 to 2.26; women = 399; studies = 2; low-quality evidence). Although the incidence of perinatal death in the progesterone group was higher, there was considerable uncertainty around the effect estimate and high heterogeneity between studies (average RR 1.45, 95% CI 0.60 to 3.51; infants = 3089; studies = 6; I2 = 71%; low-quality evidence). No studies reported maternal mortality or major neurodevelopmental disability at childhood follow-up.There were no clear group differences found in any of the other maternal or infant outcomes (preterm birth less than 37 weeks (RR 1.05, 95% CI 0.98 to 1.13; women = 2010; studies = 5; high-quality evidence); preterm birth less than 28 weeks (RR 1.08, 95% CI 0.75 to 1.55; women = 1920; studies = 5; moderate-quality evidence); infant birthweight less than 2500 g (RR 0.99, 95% CI 0.90 to 1.08; infants = 4071; studies = 5; I2 = 76%, moderate-quality evidence)). No childhood outcomes were reported in the trials. 2 Vaginal progesterone versus no treatment or placebo by doseThere were no clear group differences in incidence of preterm birth before 34 weeks (average RR 0.83, 95% CI 0.63 to 1.09; women = 1727; studies = 6; I2 = 46%; low-quality evidence). Although fewer births before 34 weeks appeared to occur in the progesterone group, the CIs crossed the line of no effect. Incidence of perinatal death was higher in the progesterone group, although there was considerable uncertainty in the effect estimate and the quality of the evidence was low for this outcome (RR 1.23, 95% CI 0.74 to 2.06; infants = 2287; studies = 3; low-quality evidence). No studies reported maternal mortality or major neurodevelopmental disability at childhood follow-up.There were no clear group differences found in any of the other maternal or infant outcomes (preterm birth less than 37 weeks (average RR 0.97, 95% CI 0.89 to 1.06; women = 1597; studies = 6; moderate-quality evidence); preterm birth less than 28 weeks (RR 1.22, 95% CI 0.68 to 2.21; women = 1569; studies = 4; low-quality evidence); infant birthweight less than 2500 g (RR 0.95, 95% CI 0.88 to 1.03; infants = 3079; studies = 4; I2 = 49%, moderate-quality evidence)). No childhood outcomes were reported in the trials.For secondary outcomes, there were no clear group differences found in any of the other maternal outcomes except for caesarean section, where women who received vaginal progesterone did not have as many caesarean sections as those in the placebo group, although the difference between groups was not large (7%) (RR 0.93, 95% CI 0.88 to 0.98; women = 2143; studies = 6; I2 = 0%). There were no clear group differences found in any of the infant outcomes except for mechanical ventilation, which was required by fewer infants whose mothers had received the vaginal progesterone (RR 0.61, 95% CI 0.48 to 0.77; infants = 3134; studies = 5).

AUTHORS' CONCLUSIONS

Overall, for women with a multiple pregnancy, the administration of progesterone (either IM or vaginal) does not appear to be associated with a reduction in risk of preterm birth or improved neonatal outcomes.Future research could focus on a comprehensive individual participant data meta-analysis including all of the available data relating to both IM and vaginal progesterone administration in women with a multiple pregnancy, before considering the need to conduct trials in subgroups of high-risk women (for example, women with a multiple pregnancy and a short cervical length identified on ultrasound).

Comparison of Risk of Preterm Labor between Vaginal Progesterone and17-Alpha-Hydroxy-Progesterone Caproate in Women with Threatened Abortion: A Randomized Clinical Trial

BACKGROUND

Threatened miscarriage is a common complication in pregnancy that leads to adverse pregnancy outcomes such as preterm labor. This study aimed to compare the vaginal progesterone (Cyclogest) versus 17-alpha-hydroxyprogesterone caproate (Proluton) on preventing preterm labor in pregnant women with threatened abortion at less than 34 weeks' gestational age.

MATERIALS AND METHODS

This balanced randomized, double-blind, single-center controlled clinical trial included 190 women with threatened abortion. They were then randomly allocated into Cyclogest (n=95) and 17-alpha-hydroxyprogesterone caproate (Proluton, n=95) groups. Interested outcome was preterm labor less than 34 weeks. The Pearson chi-square and Student's t test were used to compare two groups. The data were analyzed by Stata software version 13.

RESULTS

The risks of preterm labor less than 34 weeks in Proluton and Cyclogest groups were 8.6 and 6.52%, respectively. There was no significant difference for risk of preterm labor less than 34 weeks [relative ratio (RR): 1.31, 95% confidence interval (CI): 0.47- 3.66, P=0.59] between two groups.

CONCLUSION

Risk of preterm labor in the vaginal progesterone group and 17-alpha-hydroxyprogesterone caproate group in pregnant women with threatened abortion is the same (

REGISTRATION NUMBER

IRCT2014123120504N1).

Vaginal progesterone, but not 17α-hydroxyprogesterone caproate, has antiinflammatory effects at the murine maternal-fetal interface

OBJECTIVE

Progestogen (vaginal progesterone or 17-alpha-hydroxyprogesterone caproate [17OHP-C]) administration to patients at risk for preterm delivery is widely used for the prevention of preterm birth (PTB). The mechanisms by which these agents prevent PTB are poorly understood. Progestogens have immunomodulatory functions; therefore, we investigated the local effects of vaginal progesterone and 17OHP-C on adaptive and innate immune cells implicated in the process of parturition.

STUDY DESIGN

Pregnant C57BL/6 mice received vaginal progesterone (1 mg per 200 μL, n = 10) or Replens (control, 200 μL, n = 10) from 13 to 17 days postcoitum (dpc) or were subcutaneously injected with 17OHP-C (2 mg per 100 μL, n = 10) or castor oil (control, 100 μL, n = 10) on 13, 15, and 17 dpc. Decidual and myometrial leukocytes were isolated prior to term delivery (18.5 dpc) for immunophenotyping by flow cytometry. Cervical tissue samples were collected to determine matrix metalloproteinase (MMP)-9 activity by in situ zymography and visualization of collagen content by Masson's trichrome staining. Plasma concentrations of progesterone, estradiol, and cytokines (interferon [IFN]γ, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, keratinocyte-activated chemokine/growth-related oncogene, and tumor necrosis factor-α) were quantified by enzyme-linked immunosorbent assays. Pregnant mice pretreated with vaginal progesterone or Replens were injected with 10 μg of an endotoxin on 16.5 dpc (n = 10 each) and monitored via infrared camera until delivery to determine the effect of vaginal progesterone on the rate of PTB.

RESULTS

The following results were found: (1) vaginal progesterone, but not 17OHP-C, increased the proportion of decidual CD4+ regulatory T cells; (2) vaginal progesterone, but not 17OHP-C, decreased the proportion of decidual CD8+CD25+Foxp3+ T cells and macrophages; (3) vaginal progesterone did not result in M1→M2 macrophage polarization but reduced the proportion of myometrial IFNγ+ neutrophils and cervical active MMP-9-positive neutrophils and monocytes; (4) 17OHP-C did not reduce the proportion of myometrial IFNγ+ neutrophils; however, it increased the abundance of cervical active MMP-9-positive neutrophils and monocytes; (5) vaginal progesterone immune effects were associated with reduced systemic concentrations of IL-1β but not with alterations in progesterone or estradiol concentrations; and (6) vaginal progesterone pretreatment protected against endotoxin-induced PTB (effect size 50%, P = 0.011).

CONCLUSION

Vaginal progesterone, but not 17OHP-C, has local antiinflammatory effects at the maternal-fetal interface and the cervix and protects against endotoxin-induced PTB.

Evaluation the effect of 17-alpha hydroxyprogesterone caproate on gestational diabetes mellitus in pregnant women at risk for preterm birth

BACKGROUND

The mellitus exact role of 17-alpha hydroxyprogesterone caproate in increasing the rate of gestational diabetes mellitus (GDM) is still unclear. This study was aimed to investigate the association of treatment with 17-alpha hydroxyprogesterone caproate with GDM in pregnant women who are at risk for preterm birth (PTB).

MATERIALS AND METHODS

In this clinical trial, 200 singleton pregnant women included 100 pregnant women at risk for PTB or with history of PTB as case group (received weekly injections of 17-alpha hydroxyprogesterone caproate) and 100 healthy pregnant women without history of PTB as control group (did not receive any drug) were evaluated. All women followed until detect or reject of GDM, and abnormal glucose challenge test (GCT) and GDM were calculated in all of them.

RESULTS

During study follow-up, 36 women in both groups were excluded and 81 cases 83 controls completed the study and analyzed. Mean of GCT in all studied pregnant women was 128.2 ± 18.1, whereas, in cases was higher than controls but no significant difference was noted between groups (P = 0.56). Abnormality in GCT was observed in 32 (19.5%) of 164 studied women, (18 of cases and 14 of controls), which was not statistically significant (P = 0.34). The frequency of GDM among all studied women was 7.9% (13 of 164), 7 of cases and 6 of controls, which was not significant (P = 0.74).

CONCLUSION

In summary, results demonstrated that weekly administration of 17-alpha hydroxyprogesterone caproate is not associated with higher rates of GDM in pregnant women at risk for PTB.

Maternal characteristics influencing the development of gestational diabetes in obese women receiving 17-alpha-hydroxyprogesterone caproate

OBJECTIVE

Gestational diabetes (GDM) and obesity portend a high risk for subsequent type 2 diabetes. We examined maternal factors influencing the development of gestational diabetes (GDM) in obese women receiving 17-alpha-hydroxyprogesterone caproate (17OHPC) for preterm delivery prevention.

MATERIALS AND METHODS

Retrospectively identified were 899 singleton pregnancies with maternal prepregnancy body mass indices of ≥30 kg/m(2) enrolled for either 17OHPC weekly administration (study group) or daily uterine monitoring and nursing assessment (control group). Patients with history of diabetes type 1, 2, or GDM were excluded. Maternal characteristics were compared between groups and for women with and without development of GDM. A logistic regression model was performed on incidence of GDM, controlling for significant univariate factors.

RESULTS

The overall incidence of GDM in the 899 obese women studied was 11.9%. The incidence of GDM in the study group (n = 491) was 13.8% versus 9.6% in the control group (n = 408) (P = 0.048). Aside from earlier initiation of 17OHP and advanced maternal age, other factors including African American race, differing degrees of obesity, and use of tocolysis were not significant risks for the development of GDM.

CONCLUSION

In obese women with age greater than 35 years, earlier initiation of 17OHPC may increase the risk for GDM.

Progesterone induces apoptosis of insulin-secreting cells: insights into the molecular mechanism

Progesterone has been associated with the development of gestational diabetes (GD) due to the enhancement of insulin resistance. As β-cell apoptosis participates in type 1 and type 2 diabetes pathophysiology, we proposed the hypothesis that progesterone might contribute to the development of GD through a mechanism that also involves β-cell death. To address this question, RINm5F insulin-producing cells were incubated with progesterone (25-100 μM), in the presence or absence of α-tocopherol (40 μM). After 24 or 48 h, membrane integrity and DNA fragmentation were analyzed by flow cytometry. Caspase activity was used to identify the mode of cell death. The involvement of endoplasmic reticulum stress in the action of progesterone was investigated by western blotting. Oxidative stress was measured by 2',7'-dichlorofluorescein diacetate (DCFDA) oxidation. Isolated rat islets were used in similar experiments in order to confirm the effect of progesterone in primary β-cells. Incubation of RINm5F cells with progesterone increased the number of cells with loss of membrane integrity and DNA fragmentation. Progesterone induced generation of reactive species. Pre-incubation with α-tocopherol attenuated progesterone-induced apoptosis. Western blot analyses revealed increased expression of CREB2 and CHOP in progesterone-treated cells. Progesterone caused apoptotic death of rat islet cells and enhanced generation of reactive species. Our results show that progesterone can be toxic to pancreatic β-cells through an oxidative-stress-dependent mechanism that induces apoptosis. This effect may contribute to the development of GD during pregnancy, particularly under conditions that require administration of pharmacological doses of this hormone.

Prevention of preterm delivery in twin pregnancy

The incidence of twin gestation has increased markedly over the past decades, mostly because of increased use of assisted reproductive technologies. Twin pregnancies are at increased risk of preterm delivery (i.e. birth before 37 weeks of gestation). Multiple gestations therefore account for 2-3% of all pregnancies but constitute at least 10% of cases of preterm delivery. Complications from preterm birth are not limited to the neonatal period, such as in retinopathy of prematurity, intraventricular haemorrhage, necrotising enterocolitis, respiratory disorder and sepsis; they can also constitute sequelae such as abnormal neurophysiological development in early childhood and underachievement in school. Several treatment modalities have been proposed in singleton high-risk pregnancies. The mechanism of initiating labour may, however, be different in singleton and twin gestations. Therefore, it is mandatory to evaluate the proposed treatments in randomised trials of multiple gestations. In this chapter, we describe the results of trials to prevent preterm delivery in twin pregnancies.

Efficacy of 17α- hydroxy progestrone on decreasing preterm labor in ART pregnancies: A randomized clinical trial

BACKGROUND

Preterm labor (PTL) is one of the most important causes in neonatal mortality and morbidity. Late preterm labor (34-36w) includes 75% of such birth. Assisted reproductive technology (ART) pregnant women are at increased risk of PTL.

OBJECTIVE

The study has been undertaken to determine whether beginning and continuing 17-α hydroxy progesterone caproate can reduce risk of PTL or change neonatal mortality.

MATERIALS AND METHODS

In a double-blind clinical randomized control trial, 106 women were treated by ART technique for their infertility and in gestational age at 16 weeks entered in our study. In one group, 17-α hydroxy progesterone caproate (Femolife) was injected intramuscularly every week until 36 weeks of gestation and in another group; placebo was injected from 16 until 36 weeks of gestetion. Data collected from pregnancy outcomes, infancy, and subsidiary problems were statistically analyzed by a questionnaire.

RESULTS

The risk of PTL in placebo group was 2.48 higher than control group that was not significant (Cl: 0.81-9.94). Femolife side effect in case group was gestational diabetes and local complication was not frequent. NICU admission was not significantly different between groups.

CONCLUSION

Although it seems that 17-α hydroxy progesterone caproate does not cause significantly decrease in PTL in singleton ART gestations but any reduction of PTL in such high risk pregnancies may improve final gestational outcome. There is critical need for larger clinical trials to better understanding causes of PTL, specifically late preterm labor, to prevent mortality and morbidity in ART gestation. This article extracted from Residential thesis. (Hoora Amouzegar)

REGISTRATION ID IN IRCT

IRCT2012101611132N1.

Prenatal administration of progesterone for preventing preterm birth in women considered to be at risk of preterm birth

BACKGROUND

Preterm birth is a major complication of pregnancy associated with perinatal mortality and morbidity. Progesterone for the prevention of preterm labour has been advocated.

OBJECTIVES

To assess the benefits and harms of progesterone for the prevention of preterm birth for women considered to be at increased risk of preterm birth and their infants.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (14 January 2013) and reviewed the reference list of all articles.

SELECTION CRITERIA

Randomised controlled trials, in which progesterone was given for preventing preterm birth.

DATA COLLECTION AND ANALYSIS

Two review authors independently evaluated trials for methodological quality and extracted data.

MAIN RESULTS

Thirty-six randomised controlled trials (8523 women and 12,515 infants) were included. Progesterone versus placebo for women with a past history of spontaneous preterm birth Progesterone was associated with a statistically significant reduction in the risk of perinatal mortality (six studies; 1453 women; risk ratio (RR) 0.50, 95% confidence interval (CI) 0.33 to 0.75), preterm birth less than 34 weeks (five studies; 602 women; average RR 0.31, 95% CI 0.14 to 0.69), infant birthweight less than 2500 g (four studies; 692 infants; RR 0.58, 95% CI 0.42 to 0.79), use of assisted ventilation (three studies; 633 women; RR 0.40, 95% CI 0.18 to 0.90), necrotising enterocolitis (three studies; 1170 women; RR 0.30, 95% CI 0.10 to 0.89), neonatal death (six studies; 1453 women; RR 0.45, 95% CI 0.27 to 0.76), admission to neonatal intensive care unit (three studies; 389 women; RR 0.24, 95% CI 0.14 to 0.40), preterm birth less than 37 weeks (10 studies; 1750 women; average RR 0.55, 95% CI 0.42 to 0.74) and a statistically significant increase in pregnancy prolongation in weeks (one study; 148 women; mean difference (MD) 4.47, 95% CI 2.15 to 6.79). No differential effects in terms of route of administration, time of commencing therapy and dose of progesterone were observed for the majority of outcomes examined. Progesterone versus placebo for women with a short cervix identified on ultrasound Progesterone was associated with a statistically significant reduction in the risk of preterm birth less than 34 weeks (two studies; 438 women; RR 0.64, 95% CI 0.45 to 0.90), preterm birth at less than 28 weeks' gestation (two studies; 1115 women; RR 0.59, 95% CI 0.37 to 0.93) and increased risk of urticaria in women when compared with placebo (one study; 654 women; RR 5.03, 95% CI 1.11 to 22.78). It was not possible to assess the effect of route of progesterone administration, gestational age at commencing therapy, or total cumulative dose of medication. Progesterone versus placebo for women with a multiple pregnancy Progesterone was associated with no statistically significant differences for the reported outcomes. Progesterone versus no treatment/placebo for women following presentation with threatened preterm labour Progesterone, was associated with a statistically significant reduction in the risk of infant birthweight less than 2500 g (one study; 70 infants; RR 0.52, 95% CI 0.28 to 0.98). Progesterone versus placebo for women with 'other' risk factors for preterm birth Progesterone, was associated with a statistically significant reduction in the risk of infant birthweight less than 2500 g (three studies; 482 infants; RR 0.48, 95% CI 0.25 to 0.91).

AUTHORS' CONCLUSIONS

The use of progesterone is associated with benefits in infant health following administration in women considered to be at increased risk of preterm birth due either to a prior preterm birth or where a short cervix has been identified on ultrasound examination. However, there is limited information available relating to longer-term infant and childhood outcomes, the assessment of which remains a priority.Further trials are required to assess the optimal timing, mode of administration and dose of administration of progesterone therapy when given to women considered to be at increased risk of early birth.

17-α hydroxyprogesterone caproate for the prevention of preterm birth

17 α hydroxyprogesterone caproate is a synthetic form of the natural progestin 17-α hydroxyprogesterone that is US FDA approved for the prevention of recurrent spontaneous preterm birth in women with a history of a prior singleton preterm birth. For women with a history of a prior spontaneous preterm birth between 20 weeks and 36 weeks and 6 days of gestation, the use of 17-α hydroxyprogesterone caproate has been shown to reduce the risk of recurrent preterm birth by more than 30%. This medication is the only drug currently FDA approved for the prevention of preterm birth, and it is the first drug the FDA has approved for use exclusively during pregnancy in approximately 15 years.

Use of progestogens in pregnant and infertile patients

Progesterone is an essential hormone in the occurence and maintenance of pregnancy. Natural or synthetic progestogens are commonly used in pregnant patients or patients undergoing infertility treatments for various indications. Most frequently put indications for the use of progestogens in these patient populations are the prevention of spontaneous preterm birth, the prevention of pregnancy loss in pregnancies with an unexplained recurrent pregnancy loss and in patients with threatened abortion. It is also used in pregnant women undergoing nonobstetric surgery, for infertility or recurrent pregnancy loss that is thought to be due to luteal phase defect or as a luteal support in stimulated IVF cycles. We aimed to review the current evidence for the use of progestogens in each of these settings.

The use of vaginal natural progesterone for prevention of preterm birth in IVF/ICSI pregnancies

The aim of this study was to evaluate the effect of vaginal natural progesterone on the prevention of preterm birth in IVF/intracytoplasmic sperm injection (ICSI) pregnancies. A single-centre prospective placebo-controlled randomized study was performed. A total of 313 IVF/ICSI pregnant patients were randomized into two groups for either treatment with daily 400 mg vaginal natural progesterone or placebo, starting from mid-trimester up to 37 weeks or delivery. Amongst the patients, there were 215 singleton and 91 twin pregnancies. There was no significant difference in risk of preterm birth among all patients (OR 0.672, 95% CI 0.42-1.0. There was a significantly lower preterm birth rate in singleton pregnancies in the natural progesterone arm (OR 0.53, 95% CI 0.28-0.97) and no significant difference between both arms in twin pregnancies (OR 0.735, 95% CI 0.36-2). In conclusion, the administration of 400 mg vaginal natural progesterone from mid trimester reduced the incidence of preterm birth in singleton, but not in twin, IVF/ICSI pregnancies.

Premature delivery and the millennium development goal

Worldwide, approximately 15 million babies (1 in 10) are born prematurely each year. Prematurity is the leading cause of death among newborns, accounting for 1 million deaths per year, and, after pneumonia, is the second leading cause of death in children under age 5 years. Newborns who do survive preterm delivery (PTD) struggle with visual, auditory, and learning disabilities. In order to reach the fourth Millennium Development Goal (MDG-4) of reducing the mortality rate in children under age 5 years by two-thirds between 1990 and 2015, there must be significantly fewer PTDs. In high-income nations, 50% of babies born at 24 weeks survive, whereas in low-resource nations, this survival rate is not achieved until 32 weeks of gestation. Over 90% of babies born in low-resource settings before 28 weeks die in the first few days of life (< 10% die in high-income nations), a 10:90 survival gap. Over 60% of PTDs worldwide occur in Sub-Saharan Africa and South Asia. Risk factors for PTD include adolescent pregnancy, short interval between births, poor prepregnancy weight (very low or high body mass index), chronic diseases (diabetes and hypertension), infectious disease, substance abuse, cervical incompetence, and poor psychological health. Thus, a commitment to improving maternal health and the quality of prenatal care is necessary to achieve the MDG-4.

Definition, epidemiology, risk factors

Gestational diabetes mellitus is defined as glucose intolerance that begins or is first recognized during pregnancy. Its prevalence, generally situated between 2-6%, may reach 10-20% in high-risk populations, with an increasing trend across most racial/ethnic groups studied. Among traditional risk factors, previous gestational diabetes, advanced maternal age and obesity have the highest impact on gestational diabetes risk. Racial/ethnic origin and family history of type 2 diabetes have a significant but moderate impact (except for type 2 diabetes in siblings). Several non traditional factors have been recently characterized, either physiological (low birthweight and short maternal height) or pathological (polycystic ovaries). The multiplicity of risk factors and their interactions results in a low reliability of risk prediction on an individual basis.

[Obstetrical care in gestational diabetes and management of preterm labor]

OBJECTIVES

Search for data necessary to elaborate recommendations for obstetrical care in gestational diabetes and management of preterm labor.

METHODS

Systematic review of the literature and levels of evidence.

RESULTS

In case of gestational diabetes and in the absence of disease or other risk factor associated, there is no evidence to support a systematic rate of clinical follow up different from other pregnancy. The relevance of ultrasound estimates of fetal weight is limited. No formula is superior to others or to the simple measurement of abdominal circumference for the prediction of macrosomia (EL3). The usefulness of the research septal hypertrophy is not demonstrated (EL4). The systematic application of umbilical Doppler has no proven benefits in the absence of growth restriction or hypertension associated (EL4). Monthly ultrasound monitoring of the fetus can be proposed for diabetics on insulin or poorly controlled. In cases of gestational diabetes controlled by diet, cardiotocography of fetal heart rate has not proven useful. In poorly controlled diabetes and/or on insulin, the registration may be discussed taking into account other risk factors associated (EL4). A weekly recording of fetal heart rate is often recommended in case of type 2 diabetes discovered during pregnancy. In case of preterm labor, calcium channel blockers and oxytocin antagonists can be used without specific precautions. The risk of using beta-adrenergic outweighs the benefit. Administration of corticosteroid can be done under glycemic control, with insulin therapy if necessary. Screening test for gestational diabetes should not be performed within few days after last steroid injection.

Failure of 17-hydroxyprogesterone to reduce neonatal morbidity or prolong triplet pregnancy: a double-blind, randomized clinical trial

OBJECTIVE

To test whether 17 alpha-hydroxyprogesterone caproate (17P) will reduce neonatal morbidity by increasing gestational age at delivery in triplet pregnancies.

STUDY DESIGN

Double-blind, randomized clinical trial. Mothers carrying trichorionic-triamniotic triplets were randomly assigned (in a 2:1 ratio) to weekly injections of 250 mg of 17P or placebo, starting at 16-22 weeks and continued until 34 weeks. Primary outcome was composite neonatal morbidity.

RESULTS

Fifty-six women were randomized to 17P and 25 to placebo. Composite neonatal morbidity occurred with similar frequency in the 17P and placebo groups (38% vs 41%, respectively; P = .71). Mean gestational age at delivery was not affected by 17P (31.9 vs 31.8 weeks; P = .36). There were 13 midtrimester fetal losses with 17P vs none with placebo (P < .02).

CONCLUSION

In triplet pregnancy, prophylactic treatment with 17P did not reduce neonatal morbidity or prolong gestation but was associated with increased midtrimester fetal loss.

Prenatal administration of progesterone for preventing preterm birth

BACKGROUND

Preterm birth is the major complication of pregnancy associated with perinatal mortality and morbidity and occurs in up to 6% to 10% of all births. Administration of progesterone for the prevention of preterm labour has been advocated.

OBJECTIVES

To assess the benefits and harms of progesterone administration during pregnancy in the prevention of preterm birth.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Specialised Register of Controlled Trials (March 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2004), MEDLINE (1965 to January 2005), EMBASE (1988 to August 2004), and Current Contents (1997 to August 2004).

SELECTION CRITERIA

All published and unpublished randomised controlled trials, in which progesterone was given by any route for preventing preterm birth.

DATA COLLECTION AND ANALYSIS

Standard methods of the Cochrane Collaboration and the Cochrane Pregnancy and Childbirth Group were used. Evaluation of methodological quality and trial data extraction were undertaken independently by two authors. Results are presented using relative risk with 95% confidence intervals.

MAIN RESULTS

For all women administered progesterone, there was a reduction in the risk of preterm birth less than 37 weeks (six studies, 988 participants, relative risk (RR) 0.65, 95% confidence interval (CI) 0.54 to 0.79) and preterm birth less than 34 weeks (one study, 142 participants, RR 0.15, 95% CI 0.04 to 0.64). Infants born to mothers administered progesterone were less likely to have birthweight less than 2500 grams (four studies, 763 infants, RR 0.63, 95% CI 0.49 to 0.81) or intraventricular haemorrhage (one study, 458 infants, RR 0.25, 95% CI 0.08 to 0.82). There was no difference in perinatal death between women administered progesterone and those administered placebo (five studies, 921 participants, RR 0.66, 95% CI 0.37 to 1.19). There were no other differences reported for maternal or neonatal outcomes.

AUTHORS' CONCLUSIONS

Intramuscular progesterone is associated with a reduction in the risk of preterm birth less than 37 weeks' gestation, and infant birthweight less than 2500 grams. However, other important maternal and infant outcomes have been poorly reported to date, with most outcomes reported from a single trial only (Meis 2003). It is unclear if the prolongation of gestation translates into improved maternal and longer-term infant health outcomes. Similarly, information regarding the potential harms of progesterone therapy to prevent preterm birth is limited. Further information is required about the use of vaginal progesterone in the prevention of preterm birth.