Evaluating Progestogens for Preventing Preterm birth International Collaborative (EPPPIC): meta-analysis of individual participant data from randomised controlled trials

Progesterone-mediated remodeling of the maternal-fetal interface by a PGRMC1-dependent mechanism

Implantation and maintenance of pregnancy involve intricate immunological processes that enable the developing fetus to coexist with the maternal immune system. Progesterone, a critical hormone during pregnancy, is known to promote immune tolerance and prevent preterm labor. However, the mechanism by which progesterone mediates these effects remains unclear. In this study, we investigated the role of the non-classical progesterone receptor membrane component 1 (PGRMC1) in progesterone signaling at the maternal-fetal interface. Using JEG3 cells, a trophoblast model cell line, we observed that progesterone stimulation increased the expression of human leukocyte antigen-C (HLA-C) and HLA-G, key molecules involved in immune tolerance. We also found that progesterone upregulated the expression of the transcription factor ELF3, which is known to regulate trophoblast-specific HLA-C expression. Interestingly, JEG3 cells lacked expression of classical progesterone receptors (PRs) but exhibited high expression of PGRMC1, a finding we confirmed in primary trophoblasts by mining sc-RNA seq data from human placenta. To investigate the role of PGRMC1 in progesterone signaling, we used CRISPR/Cas9 technology to knockout PGRMC1 in JEG3 cells. PGRMC1-deficient cells showed a diminished response to progesterone stimulation. Furthermore, we found that the progesterone antagonist RU486 inhibited ELF3 expression in a PGRMC1-dependent manner, suggesting that RU486 acts as a progesterone antagonist by competing for receptor binding. Additionally, we found that RU486 inhibited cell invasion, an important process for successful pregnancy, and this inhibitory effect was dependent on PGRMC1. Our findings highlight the crucial role of PGRMC1 in mediating the immunoregulatory effects of progesterone at the maternal-fetal interface.

Preterm birth in singleton pregnancies conceived by in vitro fertilization or intracytoplasmic sperm injection: an overview of systematic reviews

BACKGROUND

The rate of preterm birth of singletons conceived through in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) is increased, being as high as 15% to 16% across Europe and the United States. However, the underlying etiology, phenotype, and mechanisms initiating preterm birth (PTB) are poorly understood.

OBJECTIVE

To quantify the PTB risk and examine supposed etiology in IVF/ICSI singleton pregnancies compared to naturally conceived.

STUDY DESIGN

Overview of reviews including all available systematic reviews with meta-analysis comparing PTB risk in IVF/ICSI and naturally conceived singletons. A comprehensive search of PubMed/MEDLINE, Embase, Scopus, and Cochrane Library databases was performed up to December 31, 2023. Information available on etiology, phenotype, initiation of PTB, and relevant moderators was retrieved and employed for subgroup analyses. Random-effects meta-analysis models were used for pooling effect measures. Estimates were presented as odds ratios (ORs) with 95% confidence intervals (CIs). The extent of overlap in the original studies was measured using the corrected covered area assessment. The quality of the included reviews was evaluated with the AMSTAR 2 tool. The Grading of Recommendations Assessment, Development and Evaluation approach was applied to rate evidence certainty. The protocol was registered on PROspective Register of Systematic Reviews (CRD42023411418).

RESULTS

Twelve meta-analyses (16,522,917 pregnancies; ˃433,330 IVF/ICSI) were included. IVF/ICSI singletons showed a significantly higher PTB risk compared to natural conception (PTB ˂37 weeks: OR: 1.72, 95% CI: 1.57-1.89; PTB<32 weeks: OR: 2.19, 95% CI: 1.82-2.64). Influential analysis reinforced the strength of this association. Subgroup analyses investigating supposed etiology revealed a comparable risk magnitude for spontaneous PTB (OR: 1.79, 95% CI: 1.56-2.04) and a greater risk for iatrogenic PTB (OR: 2.28, 95% CI: 1.72-3.02). PTB risk was consistent in the subgroup of conventional IVF (OR: 1.95, 95% CI: 1.76-2.15) and higher in the subgroup of fresh only (OR: 1.79, 95% CI: 1.55-2.07) vs frozen-thawed embryo transfers (OR: 1.39, 95% CI: 1.34-1.43). There was minimal study overlap (13%). The certainty of the evidence was graded as low to very low.

CONCLUSION

Singletons conceived through IVF/ICSI have a 2-fold increased risk of PTB compared to natural conception, despite the low certainty of the evidence. There is paucity of available data on PTB etiology, phenotype, or initiation. The greater risk increase is observed in fresh embryo transfers and involves iatrogenic PTB and PTB ˂32 weeks, likely attributable to placental etiology. Future studies should collect data on PTB etiology, phenotype, and initiation. IVF/ICSI pregnancies should undertake specialistic care with early screening for placental disorders, cervical length, and growth abnormalities, allowing appropriate timely follow-up, preventive measures, and therapeutic interventions strategies.

SMFM Consult Series #70: Management of short cervix in individuals without a history of spontaneous preterm birth

Most deliveries before 34 weeks of gestation occur in individuals with no previous history of preterm birth. Midtrimester cervical length assessment using transvaginal ultrasound is one of the best clinical predictors of spontaneous preterm birth. This Consult provides guides for the diagnosis and management of a short cervix in an individual without a history of preterm birth. The following are Society for Maternal-Fetal Medicine recommendations: (1) we recommend that all cervical length measurements used to guide therapeutic recommendations be performed using a transvaginal approach and in accordance with standardized procedures as described by organizations, such as the Perinatal Quality Foundation or the Fetal Medicine Foundation (GRADE 1C); (2) we recommend using a midtrimester cervical length of ≤25 mm to diagnose a short cervix in individuals with a singleton gestation and no previous history of spontaneous preterm birth (GRADE 1C); (3) we recommend that asymptomatic individuals with a singleton gestation and a transvaginal cervical length of ≤20 mm diagnosed before 24 weeks of gestation be prescribed vaginal progesterone to reduce the risk of preterm birth (GRADE 1A); (4) we recommend that treatment with vaginal progesterone be considered at a cervical length of 21 to 25 mm based on shared decision-making (GRADE 1B); (5) we recommend that 17-alpha hydroxyprogesterone caproate, including compounded formulations, not be prescribed for the treatment of a short cervix (GRADE 1B); (6) in individuals without a history of preterm birth who have a sonographic short cervix (10-25 mm), we recommend against cerclage placement in the absence of cervical dilation (GRADE 1B); (7) we recommend that cervical pessary not be placed for the prevention of preterm birth in individuals with a singleton gestation and a short cervix (GRADE 1B); and (8) we recommend against routine use of progesterone, pessary, or cerclage for the treatment of cervical shortening in twin gestations outside the context of a clinical trial (GRADE 1B).

Study protocol for two randomised controlled trials evaluating the effects of Cerclage in the reduction of extreme preterm birth and perinatal mortality in twin pregnancies with a short cervix or dilatation: the TWIN Cerclage studies

INTRODUCTION

Twin pregnancies have a high risk of extreme preterm birth (PTB) at less than 28 weeks of gestation, which is associated with increased risk of neonatal morbidity and mortality. Currently there is a lack of effective treatments for women with a twin pregnancy and a short cervix or cervical dilatation. A possible effective surgical method to reduce extreme PTB in twin pregnancies with an asymptomatic short cervix or dilatation at midpregnancy is the placement of a vaginal cerclage.

METHODS AND ANALYSIS

We designed two multicentre randomised trials involving eight hospitals in the Netherlands (sites in other countries may be added at a later date). Women older than 16 years with a twin pregnancy at <24 weeks of gestation and an asymptomatic short cervix of ≤25 mm or cervical dilatation will be randomly allocated (1:1) to both trials on vaginal cerclage and standard treatment according to the current Dutch Society of Obstetrics and Gynaecology guideline (no cerclage). Permuted blocks sized 2 and 4 will be used to minimise the risk of disbalance. The primary outcome measure is PTB of <28 weeks. Analyses will be by intention to treat. The first trial is to demonstrate a risk reduction from 25% to 10% in the short cervix group, for which 194 patients need to be recruited. The second trial is to demonstrate a risk reduction from 80% to 35% in the dilatation group and will recruit 44 women. A cost-effectiveness analysis will be performed from a societal perspective.

ETHICS AND DISSEMINATION

This study has been approved by the Research Ethics Committees in the Netherlands on 3/30/2023. Participants will be required to sign an informed consent form. The results will be presented at conferences and published in a peer-reviewed journal. Participants will be informed about the results.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT05968794.

Cerclage plus Adjuvant Vaginal Progesterone for Preterm Birth Prevention in Patients with a Short or Dilated Cervix without Prior Preterm Birth

OBJECTIVE

 The primary objective was to determine if vaginal progesterone following cerclage for cervical length <10 mm or cervical dilation in patients without a history of spontaneous preterm birth (sPTB) decreased the risk of preterm birth at <34 weeks' gestation compared with cerclage alone. Secondary objectives were to determine if vaginal progesterone following cerclage (1) decreased the risk of preterm birth at <24, <28, and <37 weeks' gestation and (2) increased the latency period from cerclage placement to delivery compared with treatment with cerclage alone.

STUDY DESIGN

 Multicenter retrospective cohort study from 2015 to 2020 of singleton pregnancies, without prior sPTB, who had cerclage placement <24 weeks' gestation for cervical length <10 mm or cervical dilation. Exposure defined as cerclage plus vaginal progesterone postoperatively (dual therapy) and unexposed as cerclage alone (monotherapy), based on surgeon preference.

RESULTS

 We included 122 patients, 78 (64%) treated with dual therapy and 44 (36%) treated with monotherapy. In the crude analysis, dual therapy was associated with a lower risk of delivery at <28 weeks' gestation (13%) compared with monotherapy (34%; crude risk ratio: 0.38 [95% confidence interval, CI: 0.19-0.75]). When adjusted for preoperative vaginal progesterone, results were attenuated (adjusted risk ratio: 0.45 [95% CI: 0.20-1.01]). In both the crude and adjusted analyses, the risk of sPTB was not statistically different at <24, <34 or <37 weeks' gestation. Dual therapy was associated with a greater pregnancy latency from cerclage to delivery (16.3 vs. 14.4 weeks; p = 0.04), and greater gestational age at delivery (37.3 vs. 35.8 weeks' gestation; p = 0.02) compared with monotherapy.

CONCLUSION

 While not statistically significant, the risk of sPTB was lower at all gestational ages studied in patients treated with dual therapy compared with monotherapy. Dual therapy was associated with longer pregnancy latency and greater gestational age at delivery compared with monotherapy.

KEY POINTS

· Dual therapy did not decrease preterm birth risk compared with monotherapy.. · Dual therapy prolonged pregnancy compared with monotherapy.. · Dual therapy can be considered but further studies are needed..

Progesterone for Neurodevelopment in Fetuses With Congenital Heart Defects: A Randomized Clinical Trial

Importance

Neurodevelopmental outcomes for children with congenital heart defects (CHD) have improved minimally over the past 20 years.

Objectives

To assess the feasibility and tolerability of maternal progesterone therapy as well as the magnitude of the effect on neurodevelopment for fetuses with CHD.

Design, Setting, and Participants

This double-blinded individually randomized parallel-group clinical trial of vaginal natural progesterone therapy vs placebo in participants carrying fetuses with CHD was conducted between July 2014 and November 2021 at a quaternary care children's hospital. Participants included maternal-fetal dyads where the fetus had CHD identified before 28 weeks' gestational age and was likely to need surgery with cardiopulmonary bypass in the neonatal period. Exclusion criteria included a major genetic or extracardiac anomaly other than 22q11 deletion syndrome and known contraindication to progesterone. Statistical analysis was performed June 2022 to April 2024.

Intervention

Participants were 1:1 block-randomized to vaginal progesterone or placebo by diagnosis: hypoplastic left heart syndrome (HLHS), transposition of the great arteries (TGA), and other CHD diagnoses. Treatment was administered twice daily between 28 and up to 39 weeks' gestational age.

Main Outcomes and Measures

The primary outcome was the motor score of the Bayley Scales of Infant and Toddler Development-III; secondary outcomes included language and cognitive scales. Exploratory prespecified subgroups included cardiac diagnosis, fetal sex, genetic profile, and maternal fetal environment.

Results

The 102 enrolled fetuses primarily had HLHS (n = 52 [50.9%]) and TGA (n = 38 [37.3%]), were more frequently male (n = 67 [65.7%]), and without genetic anomalies (n = 61 [59.8%]). The mean motor score differed by 2.5 units (90% CI, -1.9 to 6.9 units; P = .34) for progesterone compared with placebo, a value not statistically different from 0. Exploratory subgroup analyses suggested treatment heterogeneity for the motor score for cardiac diagnosis (P for interaction = .03) and fetal sex (P for interaction = .04), but not genetic profile (P for interaction = .16) or maternal-fetal environment (P for interaction = .70).

Conclusions and Relevance

In this randomized clinical trial of maternal progesterone therapy, the overall effect was not statistically different from 0. Subgroup analyses suggest heterogeneity of the response to progesterone among CHD diagnosis and fetal sex.

Trial Registration

ClinicalTrials.gov Identifier: NCT02133573.

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.

Cost-effectiveness of universal routine sonographic cervical-length measurement at 19 to 25 weeks' gestation

BACKGROUND

National second-trimester scanning of cervical length was introduced in Israel in 2010, and in the decade thereafter, a significant systematic reduction in preterm birth and in the delivery of low birthweight babies was found among singletons.

OBJECTIVE

In this study, we sought to estimate the cost-effectiveness of a national policy mandating second-trimester cervical length screening by ultrasound, followed by vaginal progesterone treatment for short cervical length in comparison with no screening strategy.

STUDY DESIGN

We constructed a decision model comparing 2 strategies, namely (1) universal cervical length screening, and (2) no screening strategy. This study used the national delivery registry of Israel's Ministry of Health. All women diagnosed with a second-trimester cervical length <25 mm were treated with vaginal progesterone and were monitored with a bimonthly ultrasound scan for cervical dynamics and threat of early delivery. Preterm birth prevalence associated with short cervical length, the efficacy of progesterone in preterm birth prevention, and the accuracy of cervical length measurements were derived from previous studies. The cost of progesterone and bimonthly sonographic surveillance, low birthweight delivery, newborn admission to intensive care units, the first-year costs of managing preterm birth and low birthweight, and instances of handicaps and the cost of their follow-up were extracted from the publicly posted registry of Israel's Ministry of Health and Israel Social Securities data. Monte Carlo simulations decision tree mode, Tornado diagrams, and 1- and 2-way sensitivity analyses were implemented and the base case and sensitivity to parameters that were predicted to influence cost-effectiveness were calculated.

RESULTS

Without cervical length screening, the discounted quality-adjusted life years were 30.179, and with universal cervical length screening, it increased to 30.198 (difference of 0.018 quality-adjusted life years). The average cost of no screening for cervical length strategy was $1047, and for universal cervical length screening, it was reduced to $998. The calculated incremental cost-effectiveness ratio was -$2676 per quality-adjusted life year (dividing the difference in costs by the difference in quality-adjusted life years). Monte Carlo simulation of cervical length screening of 170,000 singleton newborns (rounded large number close to the number of singleton newborns in Israel) showed that 95.17% of all babies were delivered at gestational week ≥37 in comparison with 94.46% of babies with the no screening strategy. Given 170,000 singleton births, the national savings of screening for short cervical length when compared with no cervical length screening amounted to $8.31M annually, equating to $48.84 for a base case, and the incremental cost-effectiveness ratio for each case of low birthweight or very low birthweight avoided was -$14,718. A cervical length <25 mm was measured for 30,090 women, and of those, 24,650 were false positives. The major parameters that affected the incremental cost-effectiveness ratio were the incidence of preterm birth, the specificity of cervical length measurements, and the efficacy of progesterone treatment. At a preterm birth incidence of <3%, universal screening does not lead to a cost saving.

CONCLUSION

National universal cervical length screening should be incorporated into the routine anomaly scan in the second trimester, because it leads to a drop in the incidence of preterm birth and low birthweight babies in singleton pregnancies, thereby saving costs related to the newborn and gaining quality-adjusted life years.

Does Antenatal Progesterone Administration Modify the Risk of Neonatal Intraventricular Hemorrhage?

OBJECTIVE

 Progesterone administration has been associated with improved neurological outcomes following traumatic brain injury in adults. However, studies examining the effect of progesterone on the risk of neonatal intraventricular hemorrhage (IVH) are inconsistent. We sought to determine if maternal administration of intramuscular 17-α-hydroxyprogesterone caproate (17-OHPC) is associated with decreased rates of IVH in infants born before 32-weeks gestation.

STUDY DESIGN

 This is a retrospective study of liveborn singleton deliveries between 20- and 32-weeks gestation at two large academic medical centers from January 1, 2012 to August 30, 2020. Data were extracted from hospital electronic medical record data warehouses using standardized definitions and billing and diagnosis codes. We evaluated receipt of 17-OHPC in the antepartum period and diagnosis of IVH (grade I-IV, per Volpe classification) during the neonatal delivery hospitalization encounter. Bivariate and multivariate analyses were performed to examine the association between 17-OHPC and neonatal IVH adjusting for potential confounders. Odds ratio (ORs) and 95% confidence intervals (CIs) were presented.

RESULTS

 Among 749 neonates born between 20- and 32-week gestation, 140 (18.7%) of their mothers had received antenatal 17-OHPC and 148 (19.8%) were diagnosed with IVH after birth. No significant association was observed between maternal 17-OHPC and neonatal IVH in unadjusted (OR 1.14, 95% CI 0.72-1.78) or adjusted analyses (adjusted odds ratio 1.14, 95% CI 0.71-1.84). Independent of exposure to 17-OHPC, as expected, infants born <28-weeks gestation or those with very low birthweight (<1,500 g) were at an increased risk of IVH (OR 2.32, 95% CI 1.55-3.48 and OR 2.19, 95% CI 1.09-4.38, respectively).

CONCLUSION

 Antenatal maternal 17-OHPC administration was not associated with the risk of neonatal IVH. Further research may be warranted to determine whether timing, route of delivery, and duration of progesterone therapy impact rates of neonatal IVH.

KEY POINTS

· This study aimed to compare the frequency of intraventricular hemorrhage in preterm neonates exposed to antenatal 17-α-hydroxyprogesterone caproate to those not exposed.. · In neonates born at <32-weeks gestation, maternal use of progesterone is not associated with the risk of intraventricular hemorrhage.. · In contrast to preclinical and adult data, this study suggests that progesterone exposure is not associated with the prevention of neonatal brain injury..

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

BACKGROUND

Preterm birth is a leading cause of infant morbidity and mortality worldwide. The burden of prematurity underscores the need for effective risk reduction strategies. The purpose of this study is to evaluate the efficacy of progesterone therapy, both intramuscular 17-α-hydroxyprogesterone caproate (IM 17-OHPC) and vaginal progesterone, in the prevention of recurrent spontaneous preterm birth (sPTB). The co-primary outcomes included: recurrent spontaneous PTB < 37 and < 34 weeks' gestation.

METHODS

This retrospective cohort study included 637 pregnant patients that delivered at any of the three hospitals within the Los Angeles County healthcare system between October 2015 and June 2021. We compared frequencies of measured variables between each of the progesterone treated groups to no treatment using Pearson chi-squared tests and independent t-tests for categorical and continuous variables, respectively. We estimated crude and adjusted associations between each specific treatment (versus no treatment) and primary outcomes using logistic regression.

RESULTS

Recurrent sPTB < 37 weeks' gestation occurred in 22.3% (n = 64) of those in the no treatment group, 29.1% (n = 86, p = .077) in the 17-OHPC group, and 14.3% (n = 6, p = 0.325) in the vaginal progesterone group. Recurrent sPTB < 34 weeks' gestation was 6.6% (n = 19) in the no treatment group, 11.8% (n = 35, p = .043) in the 17-OHPC group, and 7.1% (n = 3, p = 1) in the vaginal progesterone group. Among all participants, neither 17-OHPC nor vaginal progesterone was significantly associated with a reduction in recurrent sPTB at any time point. Among those with a short cervix, IM 17-OHPC was positively associated with recurrent sPTB < 37 weeks' gestation (aOR 5.61; 95% CI 1.16, 42.9).

CONCLUSIONS

Progesterone therapy of any type did not reduce the risk of recurrent sPTB < 34 or < 37 weeks' gestation compared to no progesterone therapy.

Concurrent progestogen and cerclage to reduce preterm birth: a multicenter international retrospective cohort

BACKGROUND

Both progestogens and cerclage are individually effective in preterm birth prevention in high risk pregnancies. However, national and international guidelines cite a lack of data available to comment on the potential benefit of concurrent progestogen therapy after cerclage has been placed. Studies to date have been small with mixed results regarding benefit of concurrent progestogen with cerclage leaving uncertainty regarding best clinical practice.

OBJECTIVE

This study aimed to evaluate whether cerclage with progestogen therapy was superior to cerclage alone in the prevention of spontaneous preterm birth in singleton pregnancies.

METHODS

This is an international retrospective cohort study of singleton pregnancies, without major anomaly or aneuploidy, and with cerclage placed at 10 different institutions in the United States and Colombia from June 2016 to June 2020. Exclusion criteria were lack of documentation regarding whether progestogen was prescribed, unavailable delivery outcome, and pregnancy termination (spontaneous or induced) before 16 weeks' gestation. The exposure of interest was progestogen use with cerclage placement, which included those who continued to use progestogen or who started progestogen after cerclage. The comparison group consisted of those without progestogen use after cerclage placement, which included those who had no progestogen use during the entire pregnancy or who initiated progestogen and then stopped it after cerclage placement. Progestogen type, cerclage indication, maternal baseline characteristics, and maternal/neonatal outcomes were collected. The primary outcome was spontaneous preterm birth at <37 weeks. The secondary outcomes were spontaneous preterm birth at <34 weeks, gestational age at delivery, and a composite neonatal outcome including ≥1 of the following: perinatal mortality, confirmed sepsis, grade III or IV intraventricular hemorrhage, retinopathy of prematurity, respiratory distress syndrome, and bronchopulmonary dysplasia. There were planned subgroup analyses by cerclage indication, progestogen type (vaginal progesterone vs 17-hydroxyprogesterone caproate), preterm birth history, and site. Continuous variables were compared in adjusted analyses with analysis of covariance, and categorical variables were compared with multivariable logistic regression, adjusting for potential confounders with adjusted odds ratio. A Cox regression survival curve was generated to compare latency to spontaneous delivery, censored after 37 weeks.

RESULTS

During the study period, a total of 699 singletons met the inclusion criteria: 561 in the progestogen with cerclage group and 138 with cerclage alone. Baseline characteristics were similar, except the higher likelihood of previous spontaneous preterm birth in the progestogen group (61% vs 41%; P<.001). Within the progestogen group, 52% were on 17-hydroxyprogesterone caproate weekly, 44% on vaginal progesterone daily, and 3% on oral progesterone daily. Progestogen with cerclage was associated with a significantly lower frequency of spontaneous preterm birth <37 weeks (31% vs 39%; adjusted odds ratio, 0.59 [0.39-0.89]; P=.01) and <34 weeks (19% vs 27%; adjusted odds ratio, 0.55 [0.35-0.87]; P=.01), increased latency to spontaneous delivery (hazard ratio for spontaneous preterm birth <37 weeks, 0.66 [0.49-0.90]; P=.009), and lower frequency of perinatal death (7% vs 16%; adjusted odds ratio, 0.37 [0.20-0.67]; P=.001). In planned subgroup analyses, association with reduced odds of preterm birth <37 weeks persisted in those on vaginal progesterone, those without a previous preterm birth, those with ultrasound- or examination-indicated cerclage, those who started progestogen therapy before cerclage, and in sites restricted to the United States.

CONCLUSION

Use of progestogen with cerclage was associated with reduced rates of spontaneous preterm birth and early spontaneous preterm birth compared with cerclage alone. Although this study was not sufficiently powered for subgroup analysis, the strength of evidence for benefit appeared greatest for those with ultrasound- or examination-indicated cerclage, and with vaginal progesterone.

Cervical pessary versus vaginal progesterone in women with a singleton pregnancy, a short cervix, and no history of spontaneous preterm birth at less than 34 weeks' gestation: open label, multicentre, randomised, controlled trial

OBJECTIVE

To compare the effectiveness of cervical pessary and vaginal progesterone in the prevention of adverse perinatal outcomes and preterm birth in pregnant women of singletons with no prior spontaneous preterm birth at less than 34 weeks' gestation and who have a short cervix of 35 mm or less.

DESIGN

Open label, multicentre, randomised, controlled trial.

SETTING

20 hospitals and five obstetric ultrasound practices in the Netherlands.

PARTICIPANTS

Women with a healthy singleton pregnancy and an asymptomatic short cervix of 35 mm or less between 18 and 22 weeks' gestation were eligible. Exclusion criteria were prior spontaneous preterm birth at less than 34 weeks, a cerclage in situ, maternal age of younger than 18 years, major congenital abnormalities, prior participation in this trial, vaginal blood loss, contractions, cervical length of less than 2 mm or cervical dilatation of 3 cm or more. Sample size was set at 628 participants.

INTERVENTIONS

1:1 randomisation to an Arabin cervical pessary or vaginal progesterone 200 mg daily up to 36 weeks' of gestation or earlier in case of ruptured membranes, signs of infection, or preterm labour besides routine obstetric care.

MAIN OUTCOME MEASURES

Primary outcome was a composite adverse perinatal outcome. Secondary outcomes were rates of (spontaneous) preterm birth at less than 28, 32, 34, and 37 weeks. A predefined subgroup analysis was planned for cervical length of 25 mm or less.

RESULTS

From 1 July 2014 to 31 March 2022, 635 participants were randomly assigned to pessary (n=315) or to progesterone (n=320). 612 were included in the intention to treat analysis. The composite adverse perinatal outcome occurred in 19 (6%) of 303 participants with a pessary versus 17 (6%) of 309 in the progesterone group (crude relative risk 1.1 (95% confidence interval (CI) 0.60 to 2.2)). The rates of spontaneous preterm birth were not significantly different between groups. In the subgroup of cervical length of 25 mm or less, spontaneous preterm birth at less than 28 weeks occurred more often after pessary than after progesterone (10/62 (16%) v 3/69 (4%), relative risk 3.7 (95% CI 1.1 to 12.9)) and adverse perinatal outcomes seemed more frequent in the pessary group (15/62 (24%) v 8/69 (12%), relative risk 2.1 (0.95 to 4.6)).

CONCLUSIONS

In women with a singleton pregnancy with no prior spontaneous preterm birth at less than 34 weeks' gestation and with a midtrimester short cervix of 35 mm or less, pessary is not better than vaginal progesterone. In the subgroup of a cervical length of 25 mm or less, a pessary seemed less effective in preventing adverse outcomes. Overall, for women with single baby pregnancies, a short cervix, and no prior spontaneous preterm birth less than 34 weeks' gestation, superiority of a cervical pessary compared with vaginal progesterone to prevent preterm birth and consecutive adverse outcomes could not be proven.

TRIAL REGISTRATION

International Clinical Trial Registry Platform (ICTRP, EUCTR2013-002884-24-NL).

Childhood adversity and accelerated reproductive events: a systematic review and meta-analysis

OBJECTIVE

Accelerated female reproductive events represent the early onset of reproductive events involving puberty, menarche, pregnancy loss, first sexual intercourse, first birth, parity, and menopause. This study aimed to explore the association between childhood adversity and accelerated female reproductive events.

DATA SOURCES

PubMed, Web of Science, and Embase were systematically searched from September 22, 2022 to September 23, 2022.

STUDY ELIGIBILITY CRITERIA

Observational cohort, cross-sectional, and case-control studies in human populations were included if they reported the time of reproductive events for female individuals with experience of childhood adversity and were published in English.

METHODS

Two reviewers independently screened studies, obtained data, and assessed study quality, and conflicts were resolved by a third reviewer. Dichotomous outcomes were evaluated using meta-analysis, and pooled odds ratios and 95% confidence intervals were generated using random-effects models. Moderation analysis and meta-regression were used to investigate heterogeneity.

RESULTS

In total, 21 cohort studies, 9 cross-sectional studies, and 3 case-control studies were identified. Overall, female individuals with childhood adversity were nearly 2 times more likely to report accelerated reproductive events than those with no adversity exposure (odds ratio, 1.91; 95% confidence interval, 1.33-2.76; I2=99.6%; P<.001). Moderation analysis indicated that effect sizes for the types of childhood adversity ranged from an odds ratio of 1.61 (95% confidence interval, 1.23-2.09) for low socioeconomic status to 2.13 (95% confidence interval, 1.14-3.99) for dysfunctional family dynamics. Among the 7 groups based on different reproductive events, including early onset of puberty, early menarche, early sexual initiation, teenage childbirth, preterm birth, pregnancy loss, and early menopause, early sexual initiation had a nonsignificant correlation with childhood adversity (odds ratio, 2.70; 95% confidence interval, 0.88-8.30; I2=99.9%; P<.001). Considerable heterogeneity (I2>75%) between estimates was observed for over half of the outcomes. Age, study type, and method of data collection could explain 35.9% of the variance.

CONCLUSION

The literature tentatively corroborates that female individuals who reported adverse events in childhood are more likely to experience accelerated reproductive events. This association is especially strong for exposure to abuse and dysfunctional family dynamics. However, the heterogeneity among studies was high, requiring caution in interpreting the findings and highlighting the need for further evaluation of the types and timing of childhood events that influence accelerated female reproductive events.

Strategies for Safeguarding High-Risk Pregnancies From Preterm Birth: A Narrative Review

Preterm birth is the delivery of a live fetus before the 37th week of gestation. Preterm birth may stem from various factors, including premature rupture of membranes, spontaneous preterm labor, or medically induced circumstances. Premature delivery can result in serious and long-lasting difficulties even for infants who survive, as it is the leading cause of death for infants under five years old. Numerous nations have implemented initiatives to detect and track pregnant women who may give birth before their due date. Numerous therapies are available to protect these at-risk groups from the devastating effects of premature delivery, given the complex nature of preterm birth risk factors. Among the preventive measures, prophylactic progesterone appears to hold significant promise, while cervical cerclage proves effective in cases of cervical insufficiency. Conversely, pessaries show no discernible beneficial effects in reducing the risk of preterm birth. Regular antenatal visits are imperative for frequent patient evaluation and screening for potential risk factors. Adopting a healthy lifestyle can influence the risk of developing preeclampsia, with regular physical activity, a fiber-rich diet, and smoking cessation serving to mitigate the risk of preterm birth. The efficacy of bed rest in preventing preterm birth remains inconclusive due to insufficient evidence. This study aims to explore various preventive strategies for averting premature birth in high-risk women.

Suppression of progesterone by influenza A virus mediates adverse maternal and fetal outcomes in mice

Influenza A virus infection during pregnancy can cause adverse maternal and fetal outcomes but the mechanism responsible remains elusive. Infection of outbred mice with 2009 H1N1 at embryonic day (E) 10 resulted in significant maternal morbidity, placental tissue damage and inflammation, fetal growth restriction, and developmental delays that lasted through weaning. Restriction of pulmonary virus replication was not inhibited during pregnancy, but infected dams had suppressed circulating and placental progesterone (P4) concentrations that were caused by H1N1-induced upregulation of pulmonary cyclooxygenase (COX)-1-, but not COX-2-, dependent synthesis and secretion of prostaglandin (PG) F2α. Treatment with 17-α-hydroxyprogesterone caproate (17-OHPC), a synthetic progestin that is safe to use in pregnancy, ameliorated the adverse maternal and fetal outcomes from H1N1 infection and prevented placental cell death and inflammation. These findings highlight the therapeutic potential of progestin treatments for influenza during pregnancy.IMPORTANCEPregnant individuals are at risk of severe outcomes from both seasonal and pandemic influenza A viruses. Influenza infection during pregnancy is associated with adverse fetal outcomes at birth and adverse consequences for offspring into adulthood. When outbred dams, with semi-allogenic fetuses, were infected with 2009 H1N1, in addition to pulmonary virus replication, lung damage, and inflammation, the placenta showed evidence of transient cell death and inflammation that was mediated by increased activity along the arachidonic acid pathway leading to suppression of circulating progesterone. Placental damage and suppressed progesterone were associated with detrimental effects on perinatal growth and developmental delays in offspring. Treatment of H1N1-infected pregnant mice with 17-OHPC, a synthetic progestin treatment that is safe to use in pregnancy, prevented placental damage and inflammation and adverse fetal outcomes. This novel therapeutic option for the treatment of influenza during pregnancy should be explored clinically.

Omega-3 fatty acid supply in pregnancy for risk reduction of preterm and early preterm birth

This clinical practice guideline on the supply of the omega-3 docosahexaenoic acid and eicosapentaenoic acid in pregnant women for risk reduction of preterm birth and early preterm birth was developed with support from several medical-scientific organizations, and is based on a review of the available strong evidence from randomized clinical trials and a formal consensus process. We concluded the following. Women of childbearing age should obtain a supply of at least 250 mg/d of docosahexaenoic+eicosapentaenoic acid from diet or supplements, and in pregnancy an additional intake of ≥100 to 200 mg/d of docosahexaenoic acid. Pregnant women with a low docosahexaenoic acid intake and/or low docosahexaenoic acid blood levels have an increased risk of preterm birth and early preterm birth. Thus, they should receive a supply of approximately 600 to 1000 mg/d of docosahexaenoic+eicosapentaenoic acid, or docosahexaenoic acid alone, given that this dosage showed significant reduction of preterm birth and early preterm birth in randomized controlled trials. This additional supply should preferably begin in the second trimester of pregnancy (not later than approximately 20 weeks' gestation) and continue until approximately 37 weeks' gestation or until childbirth if before 37 weeks' gestation. Identification of women with inadequate omega-3 supply is achievable by a set of standardized questions on intake. Docosahexaenoic acid measurement from blood is another option to identify women with low status, but further standardization of laboratory methods and appropriate cutoff values is needed. Information on how to achieve an appropriate intake of docosahexaenoic acid or docosahexaenoic+eicosapentaenoic acid for women of childbearing age and pregnant women should be provided to women and their partners.

Integrative analysis of noncoding mutations identifies the druggable genome in preterm birth

Preterm birth affects ~10% of pregnancies in the US. Despite familial associations, identifying at-risk genetic loci has been challenging. We built deep learning and graphical models to score mutational effects at base resolution via integrating the pregnant myometrial epigenome and large-scale patient genomes with spontaneous preterm birth (sPTB) from European and African American cohorts. We uncovered previously unidentified sPTB genes that are involved in myometrial muscle relaxation and inflammatory responses and that are regulated by the progesterone receptor near labor onset. We studied genomic variants in these genes in our recruited pregnant women administered progestin prophylaxis. We observed that mutation burden in these genes was predictive of responses to progestin treatment for preterm birth. To advance therapeutic development, we screened ~4000 compounds, identified candidate molecules that affect our identified genes, and experimentally validated their therapeutic effects on regulating labor. Together, our integrative approach revealed the druggable genome in preterm birth and provided a generalizable framework for studying complex diseases.

FUNDC1-mediated mitophagy triggered by mitochondrial ROS is partially involved in 1-nitropyrene-evoked placental progesterone synthesis inhibition and intrauterine growth retardation in mice

Intrauterine growth retardation (IUGR) is a major cause of perinatal morbidity and mortality. Previous studies showed that 1-nitropyrene (1-NP), an atmospheric pollutant, induces placental dysfunction and IUGR, but the exact mechanisms remain uncertain. In this research, we aimed to explore the role of mitophagy on 1-NP-evoked placental progesterone (P4) synthesis inhibition and IUGR in a mouse model. As expected, P4 levels were decreased in 1-NP-exposed mouse placentas and maternal sera. Progesterone synthases, CYP11A1 and 3βHSD1, were correspondingly declined in 1-NP-exposed mouse placentas and JEG-3 cells. Mitophagy, as determined by LC3B-II elevation and TOM20 reduction, was evoked in 1-NP-exposed JEG-3 cells. Mdivi-1, a specific mitophagy inhibitor, relieved 1-NP-evoked downregulation of progesterone synthases in JEG-3 cells. Additional experiments showed that ULK1/FUNDC1 signaling was activated in 1-NP-exposed JEG-3 cells. ULK1 inhibitor or FUNDC1-targeted siRNA blocked 1-NP-induced mitophagy and progesterone synthase downregulation in JEG-3 cells. Further analysis found that mitochondrial reactive oxygen species (ROS) were increased and GCN2 was activated in 1-NP-exposed JEG-3 cells. GCN2iB, a selective GCN2 inhibitor, and MitoQ, a mitochondria-targeted antioxidant, attenuated GCN2 activation, FUNDC1-mediated mitophagy, and downregulation of progesterone synthases in JEG-3 cells. In vivo, gestational MitoQ supplement alleviated 1-NP-evoked reduction of placental P4 synthesis and IUGR. These results suggest that FUNDC1-mediated mitophagy triggered by mitochondrial ROS may contribute partially to 1-NP-induced placental P4 synthesis inhibition and IUGR.

Expert consensus on novel medicines to prevent preterm birth and manage preterm labour: Target product profiles

OBJECTIVE

To develop target product profiles (TPPs) for new medicines for preterm birth prevention and preterm labour management that address the real-world need of women and healthcare providers, informed by views and agreement amongst globally diverse stakeholders.

DESIGN

Mixed methods.

SETTING

Global (with a focus on low- and middle-income countries, LMICs).

SAMPLE

Global stakeholders with diverse expertise in preterm labour/birth and drug development.

METHODS

Following an initial literature review, diverse stakeholders were invited to participate in an online international survey and in-depth interviews. The level of stakeholder agreement with TPPs was assessed, and findings from interviews were synthesised to inform the final TPPs.

MAIN OUTCOMES MEASURES

Level of stakeholder agreement on the minimum and preferred requirements for preterm labour/birth medicines.

RESULTS

We performed 21 interviews. Interview participants demonstrated strong agreement on room temperature stability, no additional drug-specific clinical monitoring, and affordability in LMICs being the minimal acceptable requirements. Points of discussion were raised around the target population. Survey respondents included clinicians, researchers, funding agency staff, international public organisation staff, programme implementers, policymakers, representatives of consumer advocacy organisations and other relevant stakeholders from maternal health systems. Survey results indicated strong agreement amongst stakeholders, with only one variable in each TPP not reaching consensus (i.e. 25% disagree or strongly disagree).

CONCLUSIONS

There is strong consensus within the preterm labour/birth community on the characteristics that new medicines for preterm birth prevention and preterm labour management must achieve. These TPPs provide necessary guidance to evaluate new candidates and their potential for implementation in a range of settings.

General Principles for Counseling and Management of Triplet Pregnancies

Compared with singleton pregnancies, triplet pregnancies are associated with a significantly increased risk of adverse pregnancy outcomes. Early ultrasound examination is the best way to diagnose triplets, establish dating, and determine the number of placentas to provide appropriate counseling and monitoring. Dichorionic placentation adds risks specifically associated with a shared placenta, and limits options for intervention. Multifetal reduction is an option that can significantly improve pregnancy outcomes compared with non-reduced triplet pregnancies. Integration of a Maternal-Fetal Medicine specialist in the prenatal care for a triplet pregnancy reduces the risk of preeclampsia, preterm birth, low birthweight infants, perinatal mortality, and major neonatal morbidity.

Vaginal progesterone for preventing preterm birth and adverse perinatal outcomes in twin gestations: a systematic review and meta-analysis

OBJECTIVE

To evaluate the efficacy of vaginal progesterone for the prevention of preterm birth and adverse perinatal outcomes in twin gestations.

DATA SOURCES

MEDLINE, Embase, LILACS, and CINAHL (from their inception to January 31, 2023), Cochrane databases, Google Scholar, bibliographies, and conference proceedings.

STUDY ELIGIBILITY CRITERIA

Randomized controlled trials that compared vaginal progesterone to placebo or no treatment in asymptomatic women with a twin gestation.

METHODS

The systematic review was conducted according to the Cochrane Handbook for Systematic Reviews of Interventions. The primary outcome was preterm birth <34 weeks of gestation. Secondary outcomes included adverse perinatal outcomes. Pooled relative risks with 95% confidence intervals were calculated. We assessed the risk of bias in each included study, heterogeneity, publication bias, and quality of evidence, and performed subgroup and sensitivity analyses.

RESULTS

Eleven studies (3401 women and 6802 fetuses/infants) fulfilled the inclusion criteria. Among all twin gestations, there were no significant differences between the vaginal progesterone and placebo or no treatment groups in the risk of preterm birth <34 weeks (relative risk, 0.99; 95% confidence interval, 0.84-1.17; high-quality evidence), <37 weeks (relative risk, 0.99; 95% confidence interval, 0.92-1.06; high-quality evidence), and <28 weeks (relative risk, 1.00; 95% confidence interval, 0.64-1.55; moderate-quality evidence), and spontaneous preterm birth <34 weeks of gestation (relative risk, 0.97; 95% confidence interval, 0.80-1.18; high-quality evidence). Vaginal progesterone had no significant effect on any of the perinatal outcomes evaluated. Subgroup analyses showed that there was no evidence of a different effect of vaginal progesterone on preterm birth <34 weeks of gestation related to chorionicity, type of conception, history of spontaneous preterm birth, daily dose of vaginal progesterone, and gestational age at initiation of treatment. The frequencies of preterm birth <37, <34, <32, <30, and <28 weeks of gestation and adverse perinatal outcomes did not significantly differ between the vaginal progesterone and placebo or no treatment groups in unselected twin gestations (8 studies; 3274 women and 6548 fetuses/infants). Among twin gestations with a transvaginal sonographic cervical length <30 mm (6 studies; 306 women and 612 fetuses/infants), vaginal progesterone was associated with a significant decrease in the risk of preterm birth occurring at <28 to <32 gestational weeks (relative risks, 0.48-0.65; moderate- to high-quality evidence), neonatal death (relative risk, 0.32; 95% confidence interval, 0.11-0.92; moderate-quality evidence), and birthweight <1500 g (relative risk, 0.60; 95% confidence interval, 0.39-0.88; high-quality evidence). Vaginal progesterone significantly reduced the risk of preterm birth occurring at <28 to <34 gestational weeks (relative risks, 0.41-0.68), composite neonatal morbidity and mortality (relative risk, 0.59; 95% confidence interval, 0.33-0.98), and birthweight <1500 g (relative risk, 0.55; 95% confidence interval, 0.33-0.94) in twin gestations with a transvaginal sonographic cervical length ≤25 mm (6 studies; 95 women and 190 fetuses/infants). The quality of evidence was moderate for all these outcomes.

CONCLUSION

Vaginal progesterone does not prevent preterm birth, nor does it improve perinatal outcomes in unselected twin gestations, but it appears to reduce the risk of preterm birth occurring at early gestational ages and of neonatal morbidity and mortality in twin gestations with a sonographic short cervix. However, more evidence is needed before recommending this intervention to this subset of patients.

Suppression of progesterone by influenza A virus mediates adverse maternal and fetal outcomes in mice

Influenza A virus infection during pregnancy can cause adverse maternal and fetal outcomes, but the mechanism responsible remains elusive. Infection of outbred mice with 2009 H1N1 at embryonic day (E) 10 resulted in significant maternal morbidity, placental tissue damage and inflammation, fetal growth restriction, and developmental delays that lasted through weaning. Restriction of pulmonary virus replication was not inhibited during pregnancy, but infected dams had suppressed circulating and placental progesterone (P4) concentrations that were caused by H1N1-induced upregulation of pulmonary cyclooxygenase (COX)-1, but not COX-2-, dependent synthesis and secretion of prostaglandin (PG) F2α. Treatment with 17-α-hydroxyprogesterone caproate (17-OHPC), a synthetic progestin that is safe to use in pregnancy, ameliorated the adverse maternal and fetal outcomes from H1N1 infection and prevented placental cell death and inflammation. These findings highlight the therapeutic potential of progestin treatments for influenza during pregnancy.

Universal cervical length screening for preterm birth is not useful after 24 weeks of gestation

INTRODUCTION

Cervical length measurement using transvaginal sonography at 18+0 -24+0  weeks of gestation is used to identify women at risk of preterm delivery, who may benefit from treatment with progesterone to prevent premature birth. Few and conflicting data exist regarding the predictive value of cervical length measurement performed at later gestational ages. The primary objective of this study was to evaluate the predictive accuracy for spontaneous preterm birth of a single cervical length measurement performed between 24 and 32 weeks of gestation in asymptomatic singleton pregnancies at low risk for spontaneous preterm birth. The secondary objective was to test the predictive accuracy of different cervical length thresholds in the same population.

MATERIAL AND METHODS

This was a historical cohort study conducted in a tertiary referral hospital. A total of 2728 asymptomatic women with singleton pregnancy at low risk for spontaneous preterm birth were recruited. Of these women, 1548 had cervical length measured at 24+0 -27+6  weeks of gestation and 2191 women at 28+0 -32+0  weeks. In all, 1010 women were present in both gestational age windows. Maternal demographics, medical and obstetrical history, and pregnancy outcome were reviewed. The predictive value of cervical length for spontaneous preterm birth was evaluated through logistic regression analysis. Results were adjusted for confounding factors.

RESULTS

Overall, spontaneous preterm birth occurred in 53/2728 women (1.9%). In both the 24+0 -27+6 and 28+0 -32+0  weeks groups, a shorter cervical length was significantly associated with spontaneous preterm birth (p < 0.01), but it had a low predictive value, as shown by the receiver operating characteristics curve analysis (areas under the curve 0.62, 95% CI 0.50-0.74 for the 24+0 -27+6  weeks group, and 0.61, 95% CI 0.52-0.70 in the 28+0 -32+0  weeks group). When the predictive accuracy for preterm delivery of different cervical length cut-offs was evaluated, the sensitivity and positive predictive value were low in both gestational age windows, irrespective of the threshold used.

CONCLUSIONS

In asymptomatic women with singleton pregnancy at low risk for spontaneous preterm birth, the predictive value of cervical length after 24+0  weeks of gestation is low. Therefore, cervical length screening in these women should be discouraged.

Elevated antimüllerian hormone levels are not associated with preterm delivery after in vitro fertilization or ovulation induction

OBJECTIVE

To investigate the association between antimüllerian hormone (AMH) and preterm birth risk in a larger cohort of patients who underwent either in vitro fertilization or ovulation induction with intrauterine insemination at a US academic fertility center.

DESIGN

Retrospective cohort study.

SETTING

Single academic fertility center.

PATIENT(S)

Live singleton births from patients who underwent in vitro fertilization or ovulation induction between 2016 and 2020 at a single academic fertility center were included in this study. Patients were excluded if they had a missing prepregnancy AMH level, a pregnancy using donor oocytes or a gestational carrier, multiple gestations, a delivery before 20 weeks gestation, or a cerclage in place.

INTERVENTION(S)

AMH level.

MAIN OUTCOME MEASURE(S)

The primary outcome was the proportion of preterm delivery. Secondary outcomes included the rate of pregnancy-induced hypertension, gestational diabetes, and small for gestational age.

RESULT(S)

In the entire cohort (n = 875), 8.4% of deliveries were preterm. The mean AMH values were similar between those with term and preterm births (3.9 vs. 4.2 ng/mL). Similar proportions of patients with term and preterm deliveries had AMH levels greater than the 75th percentile (25% vs. 21%). The odds of preterm birth were similar by AMH quartile after adjusting for the history of preterm birth. Similarly, in the polycystic ovary syndrome (PCOS) cohort, there was no difference between mean AMH values of term and preterm births (n = 139, 9.6 vs. 10.0 ng/mL). The proportions of patients with PCOS with AMH levels greater than the 75th percentile were similar between those with term and preterm deliveries (25% vs. 22%). The odds of preterm birth were similar by the AMH quartile after adjusting for the history of preterm birth.

CONCLUSION(S)

Elevated AMH levels were not associated with an increased risk of preterm birth in patients who conceived after in vitro fertilization and ovulation induction, including patients with PCOS. Although studies suggest that AMH levels may help stratify the risk of preterm birth in this population, our findings indicate that further studies are needed before clinical application.

A Comparison of Vaginal and Intramuscular Progesterone for the Prevention of Recurrent Preterm Birth

OBJECTIVE

This study aimed to examine whether vaginal progesterone is noninferior to 17-α hydroxyprogesterone caproate (17OHP-C) in the prevention of recurrent preterm birth (PTB).

STUDY DESIGN

This retrospective cohort study included singleton pregnancies among women with a history of spontaneous PTB who received prenatal care at a single tertiary center from 2011 to 2016. Pregnancies were excluded if progesterone was not initiated prior to 24 weeks or the fetus had a major congenital anomaly. The primary outcome was PTB <37 weeks. A priori, noninferiority was to be established if the upper bound of the adjusted two-sided 90% confidence interval (CI) for the difference in PTB fell below 9%. Inverse probability of treatment weighting (IPTW) was used to carefully control for confounding associated with choice of treatment and PTB. Adjusted differences in PTB proportions were estimated via IPTW regression, with standard errors adjustment for multiple pregnancies per woman. Secondary outcomes included PTB <34 and <28 weeks, spontaneous PTB, neonatal intensive care unit admission, and gestational age at delivery.

RESULTS

Among 858 pregnancies, 41% (n = 353) received vaginal progesterone and 59% (n = 505) were given 17OHP-C. Vaginal progesterone use was more common later in the study period, and among women who established prenatal care later, had prior PTBs at later gestational ages, and whose race/ethnicity was neither non-Hispanic white nor non-Hispanic Black. Vaginal progesterone did not meet noninferiority criteria compared with 17-OHPC in examining PTB <37 weeks, with an IPTW adjusted difference of 3.4% (90% CI: -3.5, 10.3). For secondary outcomes, IPTW adjusted differences between treatment groups were generally small and CIs were wide.

CONCLUSION

We could not conclude noninferiority of vaginal progesterone to 17OHP-C; however, women and providers may be willing to accept a larger difference (>9%) when considering the cost and availability of vaginal progesterone versus 17OHP-C. A well-designed randomized trial is needed.

KEY POINTS

· Vaginal progesterone is not noninferior to 17OHP-C.. · PTB risk may be 10% higher with vaginal progesterone.. · Associations did not differ based on obesity status..

Vaginal progesterone for the prevention of recurrent spontaneous preterm birth

After the United States Food and Drug Administration pulled 17-alpha hydroxyprogesterone caproate from the market for its use in prevention of recurrent spontaneous preterm birth, national societies have had mixed recommendations regarding the management of patients with a singleton pregnancy and previous spontaneous preterm birth. Herein we highlight the randomized trial data and translational evidence supporting the use of vaginal progesterone for prevention of recurrent spontaneous preterm birth in singleton pregnancies. Prophylactic vaginal progesterone starting at 16 weeks and 0 days every night should be offered to patients with singletons and previous singleton spontaneous preterm birth regardless of cervical length, and continued along with placement of cerclage if a transvaginal ultrasound cervical length ≤25 mm is detected at <24 weeks.

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

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

Few randomized trials in preterm birth prevention meet predefined usefulness criteria

OBJECTIVES

We operationalized a research usefulness tool identified through literature searches and consensus and examined if randomized controlled trials (RCTs) addressing preterm birth prevention met predefined criteria for usefulness.

STUDY DESIGN AND SETTING

The usefulness tool included eight criteria combining 13 items. RCTs were evaluated for compliance with each item by multiple assessors (reviewer agreement 95-98%). Proportions of compliances with 95% confidence interval (CI) were calculated and change over time was assessed using ≧ 2010 as a cutoff.

RESULTS

Among 347 selected RCTs, published within 56 preterm birth Cochrane reviews, only 36 (10%, 95% CI = 7-14%) met more than half of the usefulness criteria. Compared to trials before 2010, recent trials used composite or surrogate (less informative) outcomes more often (13% vs. 25%, relative risk 1.91, 95% CI = 1.21-3.00). Only 16 trials reflected real practice (pragmatism) in design (5%, 95% CI = 3-7%), with no improvements over time. No trials reported involvement of mothers to reflect patients' research priorities and outcomes selection. Recent trials were more transparent.

CONCLUSION

Few preterm birth prevention RCTs met more than half of the usefulness criteria but most of usefulness criteria are improving after 2010. Use of informative outcomes, patient centeredness, pragmatism and transparency should be key targets for future research planning.

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.

Addition of cervical elastosonography to cervical length to predict preterm birth in pregnancy women with prior preterm birth: A preliminary prospective study

OBJECTIVES

To investigate the characteristics of cervical elastosonography in pregnancies and establish an ultrasound-based combing predictor for improving the prediction in pregnant women with prior-preterm birth who might ultimately undergo preterm birth (PTB).

MATERIALS AND METHODS

169 singleton pregnancies with prior-preterm birth were examined by cervical elastography from January to November of 2021. According to the ultrasound image and result of the following-up, the patients were separated into preterm groups and full-term groups with or without cerclage. There were five elastographic parameters: Elasticity Contrast Index (ECI), Cervical hard tissue Elasticity Ratio (CHR), External Cervical os Strain rate (ES), Closed Internal Cervical os Strain rate (CIS), CIS/ES ratio and CLmin. Multivariable logistic regression was used to screen out the most significant predictors. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the ability of prediction.

RESULTS

The PTB group without cerclage showed significantly softer cervix stiffness, while those with cerclage showed significantly harder. CHRmin with P < 0.05 in the univariate logistic regression analysis was screened as a more valuable cervical elastosonography parameter than other ones. The combination of CLmin and CHRmin in un-cerclage and integrating CHRmin, maternal age and pre-pregnancy BMI in cerclage presented good predictive value. The results of AUC were higher than CLmin, respectively (0.775 vs 0.734, 0.729 vs 0.548).

CONCLUSIONS

The addition of cervical elastography parameters (such as CHRmin) might improve the ability to predict preterm birth in pregnant women with previous preterm delivery, which was better than using CL alone.

A systematic review of prediction models for spontaneous preterm birth in singleton asymptomatic pregnant women with risk factors

Backgrounds

Spontaneous preterm birth (SPB) is a global problem. Early screening, identification, and prevention in asymptomatic pregnant women with risk factors for preterm birth can help reduce the incidence and mortality of preterm births. Therefore, this study systematically reviewed prediction models for spontaneous preterm birth, summarised the model characteristics, and appraised their quality to identify the best-performing prediction model for clinical decision-making.

Methods

PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, China Biology Medicine disc, VIP Database, and Wanfang Data were searched up to September 27, 2021. Prediction models for spontaneous preterm births in singleton asymptomatic pregnant women with risk factors were eligible for inclusion. Six independent reviewers selected the eligible studies and extracted data from the prediction models. The findings were summarised using descriptive statistics and visual plots.

Results

Twelve studies with twelve developmental models were included. Discriminative performance was reported in 11 studies, with an Area Under the Curve (AUC) ranging from 0.75 to 0.95. The AUCs of the seven models were greater than 0.85. Cervical length (CL) is the most commonly used predictor of spontaneous preterm birth. A total of 91.7% of the studies had a high risk of bias in the analysis domain, mainly because of the small sample size and lack of adjustment for overfitting.

Conclusion

The accuracy of the models for spontaneous preterm births in singleton asymptomatic women with risk factors was good. However, these models are not widely used in clinical practice because they lack replicability and transparency. Future studies should transparently report methodological details and consider more meaningful predictors with new progress in research on preterm birth.

Multiple pregnancies, the myometrium and the role of mechanical factors in the timing of labour

Multiple pregnancy remains a relatively common occurrence, but it is associated with increased risks of adverse outcomes for the mother and her babies and presents unique challenges to healthcare providers. This review will briefly discuss multiple pregnancies, their aetiology and their problems, including preterm birth, before reviewing the processes leading to normal labour onset and how they may be different in a multiple pregnancy. The mechanisms by which mechanical factors i.e., uterine distension or 'stretch' contribute to uterine excitability and the timing of labour onset will be the major focus, and how over distention may pre-dispose multiple pregnancies to preterm birth. This includes current thinking around the role of mechano (stretch) sensitive ion channels in the myometrium and changes to other important regulators of excitability and contraction which have been identified from studies using in vitro and in vivo models of uterine stretch. Physiological stimuli arising from the fetus(es) and placenta(s) will also be discussed. In reviewing what we know about the myometrium in multiple pregnancy in humans, the focus will be on twin pregnancy as it is the most common type of multiple pregnancy and has been the most studied.

[Interpretation of the key updates in the 2022 European guideline on the management of neonatal respiratory distress syndrome]

With the deepening of clinical research, the management of neonatal respiratory distress syndrome (RDS) needs to be optimized and improved. This article aims to introduce the 2022 European guideline on the management of neonatal RDS, focusing on its key updates. The guide has optimized the management of risk prediction for preterm birth, maternal referral, application of prenatal corticosteroids, application of lung protective ventilation strategies, and general care for infants with RDS. The guideline is mainly applicable to the management of RDS in neonates with gestational age greater than 24 weeks.

Integration of transcriptomics and metabolomics reveals the responses of the maternal circulation and maternal-fetal interface to LPS-induced preterm birth in mice

Background

Term birth (TB) and preterm birth (PTB) are characterized by uterine contractions, rupture of the chorioamniotic membrane, decidual activation, and other physiological and pathological changes. In this study, we hypothesize that inflammation can cause changes in mRNA expression and metabolic stability in the placenta, decidua, chorioamniotic membrane, uterus and peripheral blood, ultimately leading to PTB.

Methods

To comprehensively assess the effects of inflammation on mRNA expression and metabolite production in different tissues of pregnancy, we used a mouse PTB model by intraperitoneally injecting lipopolysaccharide (LPS) and integrated transcriptomics and metabolomics studies.

Results

Our analysis identified 152 common differentially expressed genes (DEGs) and 8 common differentially expressed metabolites (DEMs) in the placenta, decidua, chorioamniotic membrane, uterus, and peripheral blood, or placenta and uterus after LPS injection, respectively. Our bioinformatics analysis revealed significant enrichment of the NOD-like receptor signaling pathway (mmu04621), TNF signaling pathway (mmu04668), IL-17 signaling pathway (mmu04657), and NF-kappa B signaling pathway in the transcriptomics of different tissues, and Hormone synthesis, Lysosome, NOD-like receptor signaling pathway, and Protein digest and absorption pathway in metabolomics. Moreover, we found that several upstream regulators and master regulators, including STAT1, STAT3, and NFKB1, were altered after exposure to inflammation in the different tissues. Interaction network analysis of transcriptomics and metabolomics DEGs and DEMs also revealed functional changes in mice intraperitoneally injected with LPS.

Conclusions

Overall, our study identified significant and biologically relevant alterations in the placenta, decidua, chorioamniotic membrane, uterus, peripheral blood transcriptome and the placenta and uterus metabolome in mice exposed to LPS. Thus, a comprehensive analysis of different pregnancy tissues in mice intraperitoneally injected with LPS by combining transcriptomics and metabolomics may help to systematically understand the local and systemic changes associated with PTB caused by inflammation.

New medicines for spontaneous preterm birth prevention and preterm labour management: landscape analysis of the medicine development pipeline

BACKGROUND

There are few medicines in clinical use for managing preterm labor or preventing spontaneous preterm birth from occurring. We previously developed two target product profiles (TPPs) for medicines to prevent spontaneous preterm birth and manage preterm labor. The objectives of this study were to 1) analyse the research and development pipeline of medicines for preterm birth and 2) compare these medicines to target product profiles for spontaneous preterm birth to identify the most promising candidates.

METHODS

Adis Insight, Pharmaprojects, WHO international clinical trials registry platform (ICTRP), PubMed and grant databases were searched to identify candidate medicines (including drugs, dietary supplements and biologics) and populate the Accelerating Innovations for Mothers (AIM) database. This database was screened for all candidates that have been investigated for preterm birth. Candidates in clinical development were ranked against criteria from TPPs, and classified as high, medium or low potential. Preclinical candidates were categorised by product type, archetype and medicine subclass.

RESULTS

The AIM database identified 178 candidates. Of the 71 candidates in clinical development, ten were deemed high potential (Prevention: Omega-3 fatty acid, aspirin, vaginal progesterone, oral progesterone, L-arginine, and selenium; Treatment: nicorandil, isosorbide dinitrate, nicardipine and celecoxib) and seven were medium potential (Prevention: pravastatin and lactoferrin; Treatment: glyceryl trinitrate, retosiban, relcovaptan, human chorionic gonadotropin and Bryophyllum pinnatum extract). 107 candidates were in preclinical development.

CONCLUSIONS

This analysis provides a drug-agnostic approach to assessing the potential of candidate medicines for spontaneous preterm birth. Research should be prioritised for high-potential candidates that are most likely to meet the real world needs of women, babies, and health care professionals.

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

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

Evidence-based antenatal interventions to reduce the incidence of small vulnerable newborns and their associated poor outcomes

A package of care for all pregnant women within eight scheduled antenatal care contacts is recommended by WHO. Some interventions for reducing and managing the outcomes for small vulnerable newborns (SVNs) exist within the WHO package and need to be more fully implemented, but additional effective measures are needed. We summarise evidence-based antenatal and intrapartum interventions (up to and including clamping the umbilical cord) to prevent vulnerable births or improve outcomes, informed by systematic reviews. We estimate, using the Lives Saved Tool, that eight proven preventive interventions (multiple micronutrient supplementation, balanced protein and energy supplementation, low-dose aspirin, progesterone provided vaginally, education for smoking cessation, malaria prevention, treatment of asymptomatic bacteriuria, and treatment of syphilis), if fully implemented in 81 low-income and middle-income countries, could prevent 5·202 million SVN births (sensitivity bounds 2·398-7·903) and 0·566 million stillbirths (0·208-0·754) per year. These interventions, along with two that can reduce the complications of preterm (<37 weeks' gestation) births (antenatal corticosteroids and delayed cord clamping), could avert 0·476 million neonatal deaths (0·181-0·676) per year. If further research substantiates the preventive effect of three additional interventions (supplementation with omega-3 fatty acids, calcium, and zinc) on SVN births, about 8·369 million SVN births (2·398-13·857) and 0·652 million neonatal deaths (0·181-0·917) could be avoided per year. Scaling up the eight proven interventions and two intrapartum interventions would cost about US$1·1 billion in 2030 and the potential interventions would cost an additional $3·0 billion. Implementation of antenatal care recommendations is urgent and should include all interventions that have proven effects on SVN babies, within the context of access to family planning services and addressing social determinants of health. Attaining high effective coverage with these interventions will be necessary to achieve global targets for the reduction of low birthweight births and neonatal mortality, and long-term benefits on growth and human capital.

Biological and pathological mechanisms leading to the birth of a small vulnerable newborn

The pathway to a thriving newborn begins before conception and continues in utero with a healthy placenta and the right balance of nutrients and growth factors that are timed and sequenced alongside hormonal suppression of labour until a mature infant is ready for birth. Optimal nutrition that includes adequate quantities of quality protein, energy, essential fats, and an extensive range of vitamins and minerals not only supports fetal growth but could also prevent preterm birth by supporting the immune system and alleviating oxidative stress. Infection, illness, undernourishment, and harmful environmental exposures can alter this trajectory leading to an infant who is too small due to either poor growth during pregnancy or preterm birth. Systemic inflammation suppresses fetal growth by interfering with growth hormone and its regulation of insulin-like growth factors. Evidence supports the prevention and treatment of several maternal infections during pregnancy to improve newborn health. However, microbes, such as Ureaplasma species, which are able to ascend the cervix and cause membrane rupture and chorioamnionitis, require new strategies for detection and treatment. The surge in fetal cortisol late in pregnancy is essential to parturition at the right time, but acute or chronically high maternal cortisol levels caused by psychological or physical stress could also trigger labour onset prematurely. In every pathway to the small vulnerable newborn, there is a possibility to modify the course of pregnancy by supporting improved nutrition, protection against infection, holistic maternal wellness, and healthy environments.

Prevention and Therapy of Preterm Birth. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry Number 015/025, September 2022) - Part 1 with Recommendations on the Epidemiology, Etiology, Prediction, Primary and Secondary Prevention of Preterm Birth

Aim This revised guideline was coordinated by the German Society for Gynecology and Obstetrics (DGGG), the Austrian Society for Gynecology and Obstetrics (OEGGG) and the Swiss Society for Gynecology and Obstetrics (SGGG). It aims to improve the prediction, prevention, and management of preterm birth, based on evidence from the current literature, the experience of members of the guidelines commission, and the viewpoint of self-help organizations. Methods The members of the contributing professional societies and organizations developed recommendations and statements based on international literature. The recommendations and statements were presented and adopted using a formal process (structured consensus conferences with neutral moderation, written Delphi vote). Recommendations Part 1 of this short version of the guideline presents statements and recommendations on the epidemiology, etiology, prediction, and primary and secondary prevention of preterm birth.

Prevention and Therapy of Preterm Birth. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Registry Number 015/025, September 2022) - Part 2 with Recommendations on the Tertiary Prevention of Preterm Birth and on the Management of Preterm Premature Rupture of Membranes

Aim The revision of this guideline was coordinated by the German Society for Gynecology and Obstetrics (DGGG), the Austrian Society for Gynecology and Obstetrics (OEGGG) and the Swiss Society for Gynecology and Obstetrics (SGGG). The aim of the guideline is to improve the prediction, prevention and management of preterm birth based on evidence from the current literature, the experience of members of the guidelines commission, and the viewpoint of self-help organizations. Methods The members of the contributing professional societies and organizations developed recommendations and statements based on international literature. The recommendations and statements were presented and adopted using a formal process (structured consensus conferences with neutral moderation, written Delphi vote). Recommendations Part 2 of this short version of the guideline presents statements and recommendations on the tertiary prevention of preterm birth and the management of preterm premature rupture of membranes.

Barriers to progress in pregnancy research: How can we break through?

Healthy pregnancies are fundamental to healthy populations, but very few therapies to improve pregnancy outcomes are available. Fundamental concepts-for example, placentation or the mechanisms that control the onset of labor-remain understudied and incompletely understood. A key issue is that research efforts must capture the complexity of the tripartite maternal-placental-fetal system, the dynamics of which change throughout gestation. Studying pregnancy disorders is complicated by the difficulty of creating maternal-placental-fetal interfaces in vitro and the uncertain relevance of animal models to human pregnancy. However, newer approaches include trophoblast organoids to model the developing placenta and integrated data-science approaches to study longer-term outcomes. These approaches provide insights into the physiology of healthy pregnancy, which is the first step to identifying therapeutic targets in pregnancy disorders.

The Use of Mid-Pregnancy Cervical Length to Predict Preterm Birth in Brazilian Asymptomatic Twin Gestations

OBJECTIVE

 To describe a reference curve for cervical length (CL) in mid-trimester twin gestations using transvaginal ultrasound (TVU) and to investigate whether short CL increases spontaneous preterm birth (sPTB) in asymptomatic twin pregnancies.

METHODS

 This was a prospective cohort study performed at 17 outpatient antenatal facilities of Brazil with women at 18 0/7 to 22 6/7 weeks of gestation who participated in a randomized clinical trial screening phase (P5 trial) between July 2015 and March 2019. TVU was performed to provide CL measurement in all screened women. Almost all women with CL ≤ 30 mm received vaginal progesterone 200mg/day and they were also randomized to receive cervical pessary or not. We considered data from the CL distribution among asymptomatic twin pregnancies and analyzed CL and its association with PTB generating receiver operating characteristics (ROC) curves and Kaplan-Meier curves.

RESULTS

 A total of 253 pregnant women with twins were included in the distribution curve. The mean CL was 33.7 mm and median was 35.5mm. The 10th percentile was 17.8mm. We identified a PTB rate of 73.9% (187/253) with 33.6% of sPTB < 37 (85/253) and 15% (38/253) of sPTB < 34 weeks. The best cutoff point to predict sPTB < 37 was 24.15 mm. However, the ROC curve showed a poor performance (0.64). The Kaplan-Meier survival curves identified that only CL values ≤ 20mm were associated to sPTB < 34 weeks.

CONCLUSION

 A cutoff point of CL ≤ 20 mm can be interesting point to identify short cervix in Brazilian twin pregnancies. However, in Brazilian asymptomatic twin pregnancies, CL does not show a good performance to predict PTB.

Comparison of International Guidelines on the Management of Twin Pregnancy

OBJECTIVES

To review current international clinical guidelines on the antenatal and intrapartum management of twin pregnancies, examining areas of consensus and conflict.

METHODS

We conducted a database search using Medline, Pubmed, Scopus, Academic Search Complete, CINAHL and ERCI Guidelines website. Guidelines were screened for eligibility using our inclusion and exclusion criteria. Those deemed eligible were quality assessed using the AGREE II tool and relevant data was extracted.

RESULTS

We identified 21 relevant guidelines from 16 countries including two international society guidelines. There was consensus in determination of chorionicity and amnionicity within the first trimester, fetal anomaly scan between 18 and 22 weeks and the recommended screening for twin-to-twin transfusion syndrome (TTTS). For those that provided intrapartum guidance, there was agreement in recommending caesarean section to deliver monochorionic monoamniotic (MCMA) twins, epidural anaesthesia for intrapartum analgesia and the use of cardiotocography (CTG) for intrapartum fetal monitoring. The main areas of conflict included cervical length screening, frequency of ultrasound surveillance, timing of delivery of dichorionic twin pregnancies and circumstances for recommending vaginal delivery. There was a lack of advice on intrapartum management.

CONCLUSIONS

This review has highlighted the need for unified international guidance on the management of twin pregnancy. Comparisons of current guidance demonstrates a lack of confidence in the management of labour in twin pregnancies. Further evidence on intrapartum care of twin pregnancies is needed to inform practice guidelines and improve both short and long term maternal and fetal outcomes.

Nanomedicine strategies to improve therapeutic agents for the prevention and treatment of preterm birth and future directions

The World Health Organisation (WHO) estimates 15 million babies worldwide are born preterm each year, with 1 million infant mortalities and long-term morbidity in survivors. Whilst the past 40 years have provided some understanding in the causes of preterm birth, along with development of a range of therapeutic options, notably prophylactic use of progesterone or uterine contraction suppressants (tocolytics), the number of preterm births continues to rise. Existing therapeutics used to control uterine contractions are restricted in their clinical use due to pharmacological drawbacks such as poor potency, transfer of drugs to the fetus across the placenta and maternal side effects from activity in other maternal systems. This review focuses on addressing the urgent need for the development of alternative therapeutic systems with improved efficacy and safety for the treatment of preterm birth. We discuss the application of nanomedicine as a viable opportunity to engineer pre-existing tocolytic agents and progestogens into nanoformulations, to improve their efficacy and address current drawbacks to their use. We review different nanomedicines including liposomes, lipid-based carriers, polymers and nanosuspensions highlighting where possible, where these technologies have already been exploited e.g. liposomes, and their significance in improving the properties of pre-existing therapeutic agents within the field of obstetrics. We also highlight where active pharmaceutical agents (APIs) with tocolytic properties have been used for other clinical indications and how these could inform the design of future therapeutics or be repurposed to diversify their application such as for use in preterm birth. Finally we outline and discuss the future challenges.

Obstetric Indications for Progestin Therapy

Specifically, meta-analyses of randomized trials demonstrate that vaginal progesterone reduces the risk of preterm birth in selected high-risk singleton pregnancies. 17-OHPC may also reduce the risk of recurrent preterm birth in singletons. Finally, one trial suggests that vaginal progesterone may also be beneficial in improving live birth rates in singletons with prior miscarriages and early pregnancy bleeding.

Progestogens for maintenance tocolysis in symptomatic women. A systematic review and meta-analysis

OBJECTIVE

Prevention of preterm birth (PTB) with progestogens after an episode of threatened preterm labour is still controversial. As different progestogens have distinct molecular structures and biological effects, we conducted a systematic review and pairwise meta-analysis to investigate the individual role played by 17-alpha-hydroxyprogesterone caproate (17-HP), vaginal progesterone (Vaginal P) and oral progesterone (Oral P).

METHODS

The search was performed in MEDLINE, ClinicalTrials.gov and the Cochrane Central Register of Controlled Trials (CENTRAL) up to 31 October 2021. Published RCTs comparing progestogens to placebo or no treatment for maintenance tocolysis were considered. We included women with singleton gestations, excluding quasi-randomized trials, studies on women with preterm premature rupture of membrane, or receiving maintenance tocolysis with other drugs. Primary outcomes were preterm birth (PTB) < 37 weeks' and < 34 weeks'. We assessed risk of bias and evaluated certainty of evidence with the GRADE approach.

RESULTS

Seventeen RCTs including 2152 women with singleton gestations were included. Twelve studies tested vaginal P, five 17-HP, and only 1 oral P. PTB < 34 weeks' did not differ among women receiving vaginal P (RR 1.21, 95%CI 0.91 to 1.61, 1077 participants, moderate certainty of evidence), or oral P (RR 0.89, 95%CI 0.38 to 2.10, 90 participants, low certainty of evidence) as opposed to placebo. Instead, 17-HP significantly reduced the outcome (RR 0.72, 95% CI 0.54 to 0.95, 450 participants, moderate certainty of evidence). PTB < 37 weeks' did not differ among women receiving vaginal P (RR 0.95, 95%CI 0.72 to 1.26, 8 studies, 1231 participants, moderate certainty of evidence) or 17-HP (RR 0.86, 95%CI 0.60 to 1.21, 450 participants, low certainty of evidence) when compared to placebo/no treatment. Instead, oral P significantly reduced the outcome (RR 0.58, 95% CI 0.36 to 0.93, 90 participants, low certainty of evidence).

CONCLUSIONS

With a moderate certainty of evidence, 17-HP prevents PTB < 34 weeks' gestation among women that remained undelivered after an episode of threatened preterm labour. However, data are insufficient to generate recommendations in clinical practice. In the same women, both 17-HP and vaginal P are ineffective in the prevention of PTB < 37 weeks'.

European Consensus Guidelines on the Management of Respiratory Distress Syndrome: 2022 Update

Respiratory distress syndrome (RDS) care pathways evolve slowly as new evidence emerges. We report the sixth version of "European Guidelines for the Management of RDS" by a panel of experienced European neonatologists and an expert perinatal obstetrician based on available literature up to end of 2022. Optimising outcome for babies with RDS includes prediction of risk of preterm delivery, appropriate maternal transfer to a perinatal centre, and appropriate and timely use of antenatal steroids. Evidence-based lung-protective management includes initiation of non-invasive respiratory support from birth, judicious use of oxygen, early surfactant administration, caffeine therapy, and avoidance of intubation and mechanical ventilation where possible. Methods of ongoing non-invasive respiratory support have been further refined and may help reduce chronic lung disease. As technology for delivering mechanical ventilation improves, the risk of causing lung injury should decrease, although minimising time spent on mechanical ventilation by targeted use of postnatal corticosteroids remains essential. The general care of infants with RDS is also reviewed, including emphasis on appropriate cardiovascular support and judicious use of antibiotics as being important determinants of best outcome. We would like to dedicate this guideline to the memory of Professor Henry Halliday who died on November 12, 2022.These updated guidelines contain evidence from recent Cochrane reviews and medical literature since 2019. Strength of evidence supporting recommendations has been evaluated using the GRADE system. There are changes to some of the previous recommendations as well as some changes to the strength of evidence supporting recommendations that have not changed. This guideline has been endorsed by the European Society for Paediatric Research (ESPR) and the Union of European Neonatal and Perinatal Societies (UENPS).

Low-dose aspirin use in the first trimester of pregnancy and odds of congenital anomalies: A meta-analysis of randomized controlled trials

BACKGROUND

Daily low-dose aspirin (LDA) is recommended in high-risk pregnancies. However, its safety profile in the first trimester has not been well documented.

OBJECTIVES

To determine if LDA exposure during the first trimester of pregnancy is associated with higher odds of congenital structural anomalies.

SEARCH STRATEGY

PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov were systematically searched.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that assigned participants to LDA (≤150 mg) or placebo/no intervention at less than 14 weeks of pregnancy were eligible.

DATA COLLECTION AND ANALYSIS

Random-effects models were performed using the inverse-variance method to calculate pooled effect sizes. Quality of evidence was appraised according to Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria.

MAIN RESULTS

Eight RCTs that included 7564 participants assigned to receive daily LDA and 7670 participants that served as controls were analyzed. Low-certainty evidence showed no significant difference in the odds of congenital anomalies (odds ratio 0.87, 95% confidence interval 0.62-1.23, I²  = 0%).

CONCLUSIONS

In this meta-analysis, there is no evidence to suggest safety concerns regarding LDA teratogenicity. However, given the overall low quality of evidence, further research (e.g. individual participant data meta-analysis) is needed to confirm LDA safety profile.