Effects of prophylactic vaginal progesterone administration on mild cervical shortening (TROPICAL study): a multicenter, double-blind, randomized trial

Nationwide status of progestogen treatment to prevent spontaneous preterm birth: A questionnaire survey for childbirth healthcare facilities in Japan

AIM

This study aimed to investigate the current status of progestogen treatment for pregnant women at a high risk for preterm birth (PTB) in childbirth healthcare facilities in Japan.

METHODS

A web-based nationwide questionnaire survey regarding progestogen use for prevention of PTB was conducted among childbirth healthcare facilities from 2019 to 2021.

RESULTS

Valid responses were obtained from 528 facilities (25.2% of those surveyed), including 155 tertiary perinatal facilities (making up 92.3% of all tertiary perinatal care facilities). In the survey period, progestogen treatment was implemented in 207 facilities (39.2%) for PTB prevention. Regarding types of progestogens, 17α-hydroxyprogesterone caproate was used in 170 facilities (82.1%), with a low dose (125 mg/week) administered in 62.9% of the facilities to comply with the regulations of the national health insurance system, although 250 mg/week is considered the best dose. Vaginal progesterone was used in 36 facilities (17.4%), although the cost of vaginal progesterone was not covered by health insurance. Of the facilities not administering progestogen treatment, approximately 40% expressed that vaginal progesterone would be their first choice for PTB prevention in daily practice if it would be covered by health insurance in the future.

CONCLUSIONS

Due to the current regulations of the Japanese health insurance system, 17α-hydroxyprogesterone caproate, rather than vaginal progesterone, was mainly used for PTB prevention. Despite global evidence supporting vaginal progesterone as the approach with the highest efficacy, only a limited number of facilities have utilized it due to the current drug use regulations in Japan.

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].

Does a cervical pessary reduce the rate of preterm birth in women with a short cervix?

OBJECTIVES

To evaluate neonatal outcomes after the use of a cervical pessary in Japanese women with short cervical length (CL) less than 25 mm.

METHODS

This multicenter study involved women with singleton pregnancies between 20 and 29+6 gestational weeks and a CL of less than 25 mm. The primary outcome was preterm birth (PTB) before 34 weeks of gestation. This study was registered in the Japan Registry of Clinical Trials (JRCT: jRCTs042180102).

RESULTS

Two hundred pregnant women were enrolled; 114 in the pessary group and 86 in the expectant management group as controls. In the pessary group, all 114 neonates were investigated for perinatal outcomes, and 112 pregnant women were investigated for primary, and secondary outcomes. In the control group, 86 pregnant women were investigated for primary and secondary outcomes and 86 neonates were investigated for neonatal outcomes. There were no significant differences in PTB in ≤34, ≤37, and ≤28 weeks of gestation or in preterm rupture of membranes (PROM) ≤34 weeks between the groups. The gestational weeks at birth and birth weight were significantly higher in the pessary group. Regression analysis demonstrated that the CL decreased without a pessary, whereas the shortening rate was suppressed during the intervention. No significant differences were observed in adverse neonatal outcomes, chorioamnionitis, or preterm PROM.

CONCLUSIONS

The cervical pessary effectively reduced CL shortening during pregnancy resulting in an average increased gestational age, however, did not reduced the rates of preterm birth.

Progesterone Suppresses Uterine Contraction by Reducing Odontogenic Porphyromonas gingivalis Induced Chronic Inflammation in Mice

Preterm birth is one of the most significant obstetric complications. Inflammation reportedly promotes uterine contraction and weakening of the fetal membrane, which induces preterm birth. Previous studies using animal models of lipopolysaccharide-induced acute inflammation have shown that progesterone (P4) promotes uterine quiescence. However, this effect is not fully understood in chronic inflammation. This study aimed to investigate the effects of P4 on uterine contractility and inflammation of the fetal membrane in mice infected with Porphyromonas gingivalis (P.g.), a major periodontal pathogen as a model of preterm birth caused by chronic inflammation. Mice were injected with 1 mg of P4 from day 15.5 to 17.5. P4 prolonged the mean gestation period of P.g mice from 18.3 to 20.4 days, and no reduction in the gestation period was observed. P4 treatment suppressed spontaneous uterine contractility and decreased oxytocin sensitivity. In addition, the expression of inflammatory cytokines in the fetal membrane was significantly reduced. Thus, P4 prevented preterm birth by suppressing enhanced uterine contractility induced by chronic inflammation in this model. This result describes the effects of P4 in a chronic inflammation model, which may lead to a better understanding of the efficacy of P4 in preventing preterm birth in humans.