Maintenance therapy with oxytocin antagonists for inhibiting preterm birth after threatened preterm labour

Vaginal Progesterone for Pregnancy Prolongation After Arrested Preterm Labor: A Randomized Clinical Trial

Importance

Women with arrested preterm labor (APTL) are at very high risk for spontaneous preterm delivery (SPTD), the leading cause of neonatal mortality and morbidity. To date, no maintenance therapy has been found to be effective for pregnancy prolongation. A few clinical trials with considerable methodological limitations have demonstrated some efficacy for 400 mg vaginal micronized progesterone (VMP) in women with APTL.

Objective

To investigate the effectiveness of daily 400 mg VMP for the prolongation of pregnancy after APTL.

Design, Setting, and Participants

This randomized clinical trial was conducted between December 19, 2018, and February 27, 2023, in 3 university-affiliated medical centers in Israel. Participants included women with singleton and twin pregnancies after APTL following tocolysis at 24 weeks 0 days to 34 weeks 0 days' gestation. Women with a history of preterm delivery or asymptomatic cervical shortening in the current pregnancy were excluded.

Interventions

Participants were randomly allocated to receive VMP 200 mg twice a day or no treatment until 36 weeks 6 days' gestation.

Main Outcomes and Measures

The primary end points were mean number of days from study enrollment to delivery and the rate of SPTD prior to 37 weeks' gestation.

Results

A total of 129 participants were enrolled (65 in the VMP group and 64 in the no-treatment group). Mean (SD) age was 27.6 (5.1) years. Between the VMP and no-treatment groups, there was no difference in pregnancy prolongation (mean [SD], 40.0 [17.8] vs 37.4 [20.3] days; P = .44) and the rate of SPTD (16 [25%] vs 19 [30%]; relative risk, 0.8; 95% CI, 0.5-1.5; P = .52). In twin pregnancies, including 12 and 15 pairs in the VMP and no-treatment groups, respectively, VMP prolonged pregnancy (mean [SD], 43.7 [18.1] vs 26.1 [15.2] days; P = .02), postponed the delivery week (36.5 [1.4] vs 34.7 [2.2] weeks; P = .01), shortened the length of stay in the neonatal intensive care unit (4.9 [10.6] vs 13.2 [18.5] days; P = .03) and overall hospital stay (8.3 [9.6] vs 15.1 [17.2] days; P = .03), and was associated with a higher birth weight (2444 [528] vs 2018 [430] g; P = .01).

Conclusions and Relevance

These findings show that VMP given in a dosage of 200 mg twice a day following APTL is not an effective treatment to prolong pregnancy or prevent SPTD. However, VMP demonstrated beneficial effects in twin pregnancies, warranting further investigation.

Trial Registration

ClinicalTrials.gov Identifier: NCT02430233.

Development and validation of a transcriptomic signature-based model as the predictive, preventive, and personalized medical strategy for preterm birth within 7 days in threatened preterm labor women

Preterm birth (PTB) is the leading cause of neonatal death. The essential strategy to prevent PTB is the accurate identification of threatened preterm labor (TPTL) women who will have PTB in a short time (< 7 days). Here, we aim to propose a clinical model to contribute to the effective prediction, precise prevention, and personalized medical treatment for PTB < 7 days in TPTL women through bioinformatics analysis and prospective cohort studies. In this study, the 1090 key genes involved in PTB < 7 days in the peripheral blood of TPTL women were ascertained using WGCNA. Based on this, the biological basis of immune-inflammatory activation (e.g., IFNγ and TNFα signaling) as well as immune cell disorders (e.g., monocytes and Th17 cells) in PTB < 7 days were revealed. Then, four core genes (JOSD1, IDNK, ZMYM3, and IL1B) that best represent their transcriptomic characteristics were screened by SVM and LASSO algorithm. Therefore, a prediction model with an AUC of 0.907 was constructed, which was validated in a larger population (AUC = 0.783). Moreover, the predictive value (AUC = 0.957) and clinical feasibility of this model were verified through the clinical prospective cohort we established. In conclusion, in the context of Predictive, Preventive, and Personalized Medicine (3PM), we have developed and validated a model to predict PTB < 7 days in TPTL women. This is promising to greatly improve the accuracy of clinical prediction, which would facilitate the personalized management of TPTL women to precisely prevent PTB < 7 days and improve maternal-fetal outcomes.

Landscape of Preterm Birth Therapeutics and a Path Forward

Preterm birth (PTB) remains the leading cause of infant morbidity and mortality. Despite 50 years of research, therapeutic options are limited and many lack clear efficacy. Tocolytic agents are drugs that briefly delay PTB, typically to allow antenatal corticosteroid administration for accelerating fetal lung maturity or to transfer patients to high-level care facilities. Globally, there is an unmet need for better tocolytic agents, particularly in low- and middle-income countries. Although most tocolytics, such as betamimetics and indomethacin, suppress downstream mediators of the parturition pathway, newer therapeutics are being designed to selectively target inflammatory checkpoints with the goal of providing broader and more effective tocolysis. However, the relatively small market for new PTB therapeutics and formidable regulatory hurdles have led to minimal pharmaceutical interest and a stagnant drug pipeline. In this review, we present the current landscape of PTB therapeutics, assessing the history of drug development, mechanisms of action, adverse effects, and the updated literature on drug efficacy. We also review the regulatory hurdles and other obstacles impairing novel tocolytic development. Ultimately, we present possible steps to expedite drug development and meet the growing need for effective preterm birth therapeutics.

Short-Term Outcomes of Atosiban in the Treatment of Preterm Labour at the Sultan Qaboos University Hospital, Muscat, Oman: A tertiary care experience

Objectives

This study aimed to generate baseline evidence regarding the effectiveness of atosiban in delaying delivery by ≥48 hours among pregnant women presenting with threatened preterm labour (TPL). The secondary objective was to assess the relationship between atosiban success and various perinatal factors and neonatal outcomes.

Methods

This retrospective study was conducted between June 2008 and May 2018 at the Sultan Qaboos University Hospital, Muscat, Oman. The medical records of all pregnant women who received atosiban between 24–34 gestational weeks for TPL during this period were reviewed.

Results

A total of 159 women were included in the study. Atosiban was successful in delaying delivery by ≥48 hours in 130 cases (81.8%). Approximately half of the women (50.9%) achieved uterine quiescence in <12 hours. Failure to delay delivery by ≥48 hours was significantly lower among women with normal versus abnormal cervical findings (11.1% versus 25.6%; P = 0.023). Only 9.4% of women experienced minor side-effects. Mean birth weight (2,724.55 versus 1,707.59 g; P <0.001) and Apgar scores at 5 minutes (9.66 versus 8.28; P <0.001) were significantly higher among neonates delivered at ≥48 versus <48 hours post-atosiban, whereas the rate of neonatal respiratory distress syndrome was significantly lower (18.4% versus 81.6%; P <0.001).

Conclusion

Atosiban was highly effective in delaying delivery by ≥48 hours and resulted in few adverse maternal side-effects and neonatal outcomes. To the best of the authors’ knowledge, this is the first study conducted in Oman to evaluate the effectiveness of atosiban in preventing preterm labour.

Differences between evidence-based recommendations and actual clinical practice regarding tocolysis: a prospective multicenter registry study

BACKGROUND

International guidelines recommend that tocolytic therapy be restricted to a single 48-h application. However, multiple cycles of tocolytic therapy and maintenance therapy that exceeds 48 h appear to play a role in daily clinical practice. We aimed to evaluate current trends in clinical practice with respect to treatment with tocolytic agents and to identify differences between evidence-based recommendations and daily clinical practice in Austria.

METHODS

A prospective multicenter registry study was conducted from October 2013 through April 2015 in ten obstetrical departments in Austria. Women ≥18 years of age who received tocolytic therapy following a diagnosis of threatened preterm birth were included, and details were obtained regarding clinical characteristics, tocolytic therapy, and pregnancy outcome.

RESULTS

A total of 309 women were included. We observed a median of 2 cycles of tocolytic therapy per patient (IQR 1-3) with a median duration of 2 days per cycle (IQR 2-5). Repeat tocolysis was administered in 41.7% of women, resulting in up to six tocolysis cycles; moreover, 40.8% of the first tocolysis cycles were maintenance tocolysis (i.e., longer than 48 h). Only 25.6% of women received one single 48-h tocolysis cycle in which they received antenatal corticosteroids for fetal lung maturation in accordance evidence-based recommendations.

CONCLUSIONS

Here, we report a clear disparity between evidence-based recommendations and daily practice with respect to tocolysis. We believe that the general practice of prescribing tocolytic therapy must be revisited. Furthermore, our findings highlight the need for contemporary studies designed to investigate the effectiveness of performing maintenance and/or repetitive tocolysis treatment.

Progesterone in women with arrested premature labor, a report of a randomised clinical trial and updated meta-analysis

BACKGROUND

Progesterone may be effective in prevention of premature birth in some high risk populations. Women with arrested premature labor are at risk of recurrent labor and maintenance therapy with standard tocolytics has not been successful.

METHODS

Randomized double blinded clinical trial of daily treatment with 200 mg vaginal progesterone in women with arrested premature labor and an updated meta-analysis.

RESULTS

The clinical trial was terminated early after 41 women were enrolled. Vaginal progesterone treatment did not change the median gestational age at delivery: 36+2 weeks versus 36+4 weeks, p = .865 nor increase the mean latency to delivery: 44.5 days versus 46.6 days, p = .841. In the updated meta-analysis, progesterone treatment did reduce delivery <37 weeks gestation and increase latency to delivery, but this treatment effect was not evident in the high quality trials: (OR 1.23, 95% CI 0.91, 1.67) and (-0.95 days, 95% CI -5.54, 3.64) respectively.

CONCLUSION

Progesterone is not effective for preventing preterm birth following arrested preterm labor.