Prevention of recurrent preterm delivery by 17 alpha-hydroxyprogesterone caproate

17-Alpha-Hydroxyprogesterone vs. Placebo for Preventing of Recurrent Preterm Birth: A Systematic Review and Meta-Analysis of Randomized Trials

Background: Preterm birth (PTB) is a leading cause of neonatal morbidity and mortality. Objective: To estimate the effect of 17-alpha-hydroxyprogesterone caproate (17-OHPC) compared to placebo in singleton gestations for reducing the risk of recurrent PTB and neonatal morbidity and mortality. Work Design: Systematic review and meta-analysis. Search Strategy: Searching MEDLINE, Embase, Web of Science, SCOPUS, Cochrane Library, and clinical trial registries. Selection Criteria: Randomized controlled trials of singleton gestations with a history of PTB and treated with a weekly intramuscular injection of 17-OHPC or placebo. Data Collection and Analysis: A random meta-analysis model was performed for the PTB outcomes (<32, <35, and <37 weeks) and neonatal outcomes (neonatal death, grade 3 or 4 intraventricular hemorrhage, respiratory distress syndrome, bronchopulmonary dysplasia, necrotizing enterocolitis, and sepsis). Effect estimates were measured by relative risk ratio (RR) with a 95% confidence interval (CI). Main Results: Six works were included. There were no statistically significant reductions in the PTB risk following the use of 17-OHPC at <32 weeks (RR = 0.61, 95% CI: 0.13-2.77, and I ² = 39%), <35weeks (RR = 0.60, 95% CI: 0.10-3.67, and I ² = 51%), and <37 weeks (RR = 0.68, 95% CI: 0.46-1, and I ² = 75%). Furthermore, all the neonatal outcomes were statistically similar between the two groups. Conclusion: Treatment with 17-OHPC is not associated with reducing the risk of PTB or neonatal outcomes compared to placebo.

OBGYN practice patterns regarding combination therapy for prevention of preterm birth: A national survey

OBJECTIVE

Our objective was to examine if US obstetrician-gynecologists (OBGYNs) practice outside of evidenced-based guidelines and use a combination of interventions to prevent spontaneous preterm birth (sPTB).

STUDY DESIGN

An electronic survey was distributed to members of the Pregnancy-Related Care Research Network (PRCRN), and also to members of the Society of Maternal-Fetal Medicine (SMFM). The survey consisted of questions regarding physician demographics, and the use of interventions to prevent sPTB in women with 1) a prior sPTB, 2) an incidental short cervix (no prior sPTB), and 3) a history of cervical insufficiency.

RESULTS

The PRCRN response rate was 58.6% (283/483) with an additional 143 responses from SMFM members. Among PRCRN responders, 82.7% were general OBGYNs and 17.3% were Maternal-Fetal Medicine subspecialists. Respondents were from all geographic regions of the country; most practiced in a group private practice (42.6%) or academic institution (31.4%). In women with prior sPTB, 45.2% of respondents would consider combination therapy, most commonly weekly intramuscular progesterone (IM-P) and serial cervical length (CL) measurements. If the patient then develops a short cervix, 33.7% would consider adding an ultrasound-indicated cerclage. In women with an incidental short cervix, 66.8% of respondents were likely to recommend single therapy with daily vaginal progesterone (VP). If a patient developed an incidentally dilated cervix, 40.8% of PRCRN respondents would recommend dual therapy, most commonly cerclage + VP, whereas 64.3% of SMFM respondents were likely to continue with VP only. In women with a history of cervical insufficiency, 47% of PRCRN respondents indicated they would consider a combination of IM-P, history-indicated cerclage and serial CL measurements.

CONCLUSION

Although not currently supported by evidence-based medicine, combination therapy is commonly being used by U.S. OBGYNs to prevent sPTB in women with risk factors such as prior sPTB, short or dilated cervix or more than one of these risks.

Clinical Validation of a Proteomic Biomarker Threshold for Increased Risk of Spontaneous Preterm Birth and Associated Clinical Outcomes: A Replication Study

Preterm births are the leading cause of neonatal death in the United States. Previously, a spontaneous preterm birth (sPTB) predictor based on the ratio of two proteins, IBP4/SHBG, was validated as a predictor of sPTB in the Proteomic Assessment of Preterm Risk (PAPR) study. In particular, a proteomic biomarker threshold of -1.37, corresponding to a ~two-fold increase or ~15% risk of sPTB, significantly stratified earlier deliveries. Guidelines for molecular tests advise replication in a second independent study. Here we tested whether the significant association between proteomic biomarker scores above the threshold and sPTB, and associated adverse outcomes, was replicated in a second independent study, the Multicenter Assessment of a Spontaneous Preterm Birth Risk Predictor (TREETOP). The threshold significantly stratified subjects in PAPR and TREETOP for sPTB (p = 0.041, p = 0.041, respectively). Application of the threshold in a Kaplan-Meier analysis demonstrated significant stratification in each study, respectively, for gestational age at birth (p < 001, p = 0.0016) and rate of hospital discharge for both neonate (p < 0.001, p = 0.005) and mother (p < 0.001, p < 0.001). Above the threshold, severe neonatal morbidity/mortality and mortality alone were 2.2 (p = 0.0083,) and 7.4-fold higher (p = 0.018), respectively, in both studies combined. Thus, higher predictor scores were associated with multiple adverse pregnancy outcomes.

17-alpha hydroxyprogesterone caproate for the prevention of recurrent preterm birth among singleton pregnant women with a prior history of preterm birth: a systematic review and meta-analysis of six randomized controlled trials

To perform a systematic review and meta-analysis of all randomized controlled trials (RCTs) that investigated the clinical benefits of 17-alpha hydroxyprogesterone caproate (17OHPC) in the prevention of recurrent preterm birth (PTB) among singleton pregnant women with a previous history of PTB. We searched four major databases up till April 2021 and assessed the risk of bias in the included studies. We meta-analyzed various maternal-neonatal endpoints (n=18) and pooled them as mean difference or risk ratio (RR) with 95% confidence interval (CI) using the random-effects model. Six RCTs met the inclusion criteria, comprising 2,573 patients (17OHPC=1,617, control=956). RCTs revealed an overall low risk of bias. The rates of PTB <35 weeks (n=5 RCTs; RR, 0.77; 95% CI, 0.63–0.93; P=0.008), PTB <32 weeks (n=3 RCTs; RR, 0.68; 95% CI, 0.51–0.91; P=0.009), neonates with low birth weight (<2.5 kg) at delivery (n=3 RCTs; RR, 0.63; 95% CI, 0.5–0.79; P<0.001), and neonatal death (n=4 RCTs; RR, 0.41; 95% CI, 0.20–0.84; P=0.02) were significantly reduced in the 17OHPC group compared with the control group. Moreover, 17OHPC treatment correlated with a significantly decreased rate of retinopathy (n=2 RCTs; RR, 0.42; 95% CI, 0.18–0.97; P=0.004). However, there were no significant differences in the rates of neonatal intensive care unit admission, cesarean delivery, and other preterm-related complications between both the groups. Among singleton pregnant women with a prior history of PTB, 17OHPC may favorably decrease the risks of recurrent PTB and reduce the rate of neonatal death.

Weekly 17 alpha-hydroxyprogesterone caproate to prevent preterm birth among women living with HIV: a randomised, double-blind, placebo-controlled trial

BACKGROUND

Women with HIV face an increased risk of preterm birth. 17 alpha-hydroxyprogesterone caproate (17P) has been shown in some trials to reduce early delivery among women with a history of spontaneous preterm birth. We investigated whether 17P would reduce this risk among women with HIV.

METHODS

We did a randomised, double-blind, placebo-controlled trial in pregnant women with HIV at the University Teaching Hospital and Kamwala District Health Centre in Lusaka, Zambia. Eligible patients were women aged 18 years or older with confirmed HIV-1 infection, viable intrauterine singleton pregnancy at less than 24 weeks of gestation, and were receiving or intending to commence antiretroviral therapy during pregnancy. Exclusion criteria were major uterine or fetal anomaly; planned or in situ cervical cerclage; evidence of threatened miscarriage, preterm labour, or ruptured membranes at screening; medical contraindication to 17P; previous participation in the trial; or history of spontaneous preterm birth. Eligible participants provided written informed consent and were randomly assigned (1:1) to receive 250 mg intramuscular 17P or placebo once per week, starting between 16 and 24 weeks of gestation until delivery, stillbirth, or reaching term (37 weeks). Participants and study staff were masked to assignment, except for pharmacy staff who did random assignment and prepared injections but did not interact with participants. The primary outcome was a composite of delivery before 37 weeks or stillbirth at any gestational age. Patients attended weekly visits for study drug injections and antenatal care. We estimated the absolute and relative difference in risk of the primary outcome and safety events between treatment groups by intention to treat. This trial is registered with ClinicalTrials.gov, NCT03297216, and is complete.

FINDINGS

Between Feb 7, 2018 and Jan 13, 2020, we assessed 1042 women for inclusion into the study. 242 women were excluded after additional assessments, and 800 eligible patients were enrolled and randomly assigned to receive intramuscular 17P (n=399) or placebo (n=401). Baseline characteristics were similar between groups. Adherence to study drug injections was 98% in both groups, no patients were lost to follow-up, and the final post-partum visit was on Aug 6, 2020. 36 (9%) of 399 participants assigned to 17P had preterm birth or stillbirth, compared with 36 (9%) of 401 patients assigned to placebo (risk difference 0·1, 95% CI -3·9 to 4·0; relative risk 1·0, 95% CI 0·6 to 1·6; p=0·98). Intervention-related adverse events were reported by 140 (18%) of 800 participants and occurred in similar proportions in both randomisation groups. No serious adverse events were reported.

INTERPRETATION

Although 17P seems to be safe and acceptable to participants, available data do not support the use of the drug to prevent preterm birth among women whose risk derives solely from HIV infection. The low risk of preterm birth in both randomisation groups warrants further investigation.

FUNDING

US National Institutes of Health and the Bill and Melinda Gates Foundation.

Prevention of Preterm Birth with Progesterone

Gestational age at birth is a critical factor for perinatal and adulthood outcomes, and even for transgenerational conditions' effects. Preterm birth (PTB) (prematurity) is still the main determinant for infant mortality and morbidity leading cause of infant morbidity and mortality. Unfortunately, preterm birth (PTB) is a relevant public health issue worldwide and the global PTB rate is around 11%. The premature activation of labor is underlined by complex mechanisms, with a multifactorial origin influenced by numerous known and probably unknown triggers. The possible mechanisms involved in a too early labor activation have been partially explained, and involve chemokines, receptors, and imbalanced inflammatory paths. Strategies for the early detection and prevention of this obstetric condition were proposed in clinical settings with interesting results. Progesterone has been demonstrated to have a key role in PTB prevention, showing several positive effects, such as lower prostaglandin synthesis, the inhibition of cervical stromal degradation, modulating the inflammatory response, reducing gap junction formation, and decreasing myometrial activation. The available scientific knowledge, data and recommendations address multiple current areas of debate regarding the use of progesterone in multifetal gestation, including different formulations, doses and routes of administration and its safety profile in pregnancy.

Cost-Effectiveness of a Proteomic Test for Preterm Birth Prediction

Background

Preterm birth (PTB) carries increased risk of short- and long-term health problems as well as higher healthcare costs. Current strategies using clinically accepted maternal risk factors (prior PTB, short cervix) can only identify a minority of singleton PTBs.

Objective

We modeled the cost-effectiveness of a risk-screening-and-treat strategy versus usual care for commercially insured pregnant US women without clinically accepted PTB risk factors. The risk-screening-and-treat strategy included use of a novel PTB prognostic blood test (PreTRM^®) in the 19th–20th week of pregnancy, followed by treatment with a combined regimen of multi-component high-intensity-case-management and pharmacologic interventions for the remainder of the pregnancy for women assessed as higher-risk by the test, and usual care in women without higher risk.

Methods

We built a cost-effectiveness model using a combined decision-tree/Markov approach and a US payer perspective. We modeled 1-week cycles of pregnancy from week 19 to birth (preterm or term) and assessed costs throughout the pregnancy, and further to 12-months post-delivery in mothers and 30-months in infants. PTB rates and costs were based on >40,000 mothers and infants from the HealthCore Integrated Research Database^® with birth events in 2016. Estimates of test performance, treatment effectiveness, and other model inputs were derived from published literature.

Results

In the base case, the risk-screening-and-treat strategy dominated usual care with an estimated 870 fewer PTBs (20% reduction) and $54 million less in total cost ($863 net savings per pregnant woman). Reductions were projected for neonatal intensive care admissions (10%), overall length-of-stay (7%), and births <32 weeks (33%). Treatment effectiveness had the strongest influence on cost-effectiveness estimates. The risk-screening-and-treat strategy remained dominant in the majority of probabilistic sensitivity analysis simulations and model scenarios.

Conclusion

Use of a novel prognostic test during pregnancy to identify women at risk of PTB combined with evidence-based treatment is estimated to reduce total costs while preventing PTBs and their consequences.

Progesterone to prevent miscarriage in women with early pregnancy bleeding: the PRISM RCT

BACKGROUND

Progesterone is essential for a healthy pregnancy. Several small trials have suggested that progesterone therapy may rescue a pregnancy in women with early pregnancy bleeding, which is a symptom that is strongly associated with miscarriage.

OBJECTIVES

(1) To assess the effects of vaginal micronised progesterone in women with vaginal bleeding in the first 12 weeks of pregnancy. (2) To evaluate the cost-effectiveness of progesterone in women with early pregnancy bleeding.

DESIGN

A multicentre, double-blind, placebo-controlled, randomised trial of progesterone in women with early pregnancy vaginal bleeding.

SETTING

A total of 48 hospitals in the UK.

PARTICIPANTS

Women aged 16-39 years with early pregnancy bleeding.

INTERVENTIONS

Women aged 16-39 years were randomly assigned to receive twice-daily vaginal suppositories containing either 400 mg of progesterone or a matched placebo from presentation to 16 weeks of gestation.

MAIN OUTCOME MEASURES

The primary outcome was live birth at ≥ 34 weeks. In addition, a within-trial cost-effectiveness analysis was conducted from an NHS and NHS/Personal Social Services perspective.

RESULTS

A total of 4153 women from 48 hospitals in the UK received either progesterone (n = 2079) or placebo (n = 2074). The follow-up rate for the primary outcome was 97.2% (4038 out of 4153 participants). The live birth rate was 75% (1513 out of 2025 participants) in the progesterone group and 72% (1459 out of 2013 participants) in the placebo group (relative rate 1.03, 95% confidence interval 1.00 to 1.07; p = 0.08). A significant subgroup effect (interaction test p = 0.007) was identified for prespecified subgroups by the number of previous miscarriages: none (74% in the progesterone group vs. 75% in the placebo group; relative rate 0.99, 95% confidence interval 0.95 to 1.04; p = 0.72); one or two (76% in the progesterone group vs. 72% in the placebo group; relative rate 1.05, 95% confidence interval 1.00 to 1.12; p = 0.07); and three or more (72% in the progesterone group vs. 57% in the placebo group; relative rate 1.28, 95% confidence interval 1.08 to 1.51; p = 0.004). A significant post hoc subgroup effect (interaction test p = 0.01) was identified in the subgroup of participants with early pregnancy bleeding and any number of previous miscarriage(s) (75% in the progesterone group vs. 70% in the placebo group; relative rate 1.09, 95% confidence interval 1.03 to 1.15; p = 0.003). There were no significant differences in the rate of adverse events between the groups. The results of the health economics analysis show that progesterone was more costly than placebo (£7655 vs. £7572), with a mean cost difference of £83 (adjusted mean difference £76, 95% confidence interval -£559 to £711) between the two arms. Thus, the incremental cost-effectiveness ratio of progesterone compared with placebo was estimated as £3305 per additional live birth at ≥ 34 weeks of gestation.

CONCLUSIONS

Progesterone therapy in the first trimester of pregnancy did not result in a significantly higher rate of live births among women with threatened miscarriage overall, but an important subgroup effect was identified. A conclusion on the cost-effectiveness of the PRISM trial would depend on the amount that society is willing to pay to increase the chances of an additional live birth at ≥ 34 weeks. For future work, we plan to conduct an individual participant data meta-analysis using all existing data sets.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN14163439, EudraCT 2014-002348-42 and Integrated Research Application System (IRAS) 158326.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 33. See the NIHR Journals Library website for further project information.

Performance on a modified signal detection task of attention is impaired in male and female rats following developmental exposure to the synthetic progestin, 17α-hydroxyprogesterone caproate

Based on evidence that the developing mesocortical dopamine pathway is sensitive to progestins, in the present study we tested the hypothesis that attention, a fundamental component of successful cognitive behavior, is disrupted by developmental exposure to the synthetic progestin, 17-α-hydroxyprogesterone caproate (17-OHPC). To assess attentional impairments, a modified signal detection task was utilized with three stimulus modalities: compound (light and tone), light alone, and tone alone, for four stimulus durations (2, 0.5, 0.25, 0.125 s). Adult rats were trained to push one lever if they detected the stimulus, and another lever if the stimulus was not presented. 17-OHPC animals were able to attend to the task, as evidenced by similar correct responses as controls. However, as the task became increasingly difficult at shorter durations, 17-OHPC animals made significantly more omissions compared to controls, suggesting that 17-OHPC treatment may disrupt attentional processes and/or delay response time. These findings add to the current body of literature demonstrating that exposure to 17-OHPC during development produces deficits in cognitive behavior in adulthood. These results may inform potential risks associated with 17-OHPC treatment in pregnant women with a history of preterm delivery who are commonly recipients of such treatment.

Comparison the efficacy of vaginal progesterone versus 17-alpha-hydroxyprogesterone caproate to prevent preterm birth in high-risk pregnant women undergo cerclage: a randomized clinical trial

OBJECTIVE

The aim of this study was to compare the effect of vaginal progesterone with 17-alpha-hydroxyprogesterone caproate (17OHP-C) in prevention of preterm birth in high-risk pregnant women undergo cerclage.

MATERIALS AND METHODS

This prospective randomized clinical trial registered in the Iranian Registry of Clinical Trials (IRCT20181107041585N4), was performed from May 2017 to August 2018 in Bandar Abbas, Iran. Fifty-eight eligible women who were scheduled for cervical cerclage due to a history of two or more previous preterm birth <28 weeks or a cervical length less than 25 mm with at least one previous preterm birth <34 weeks were randomly divided into two groups. The first group received 200 mg of vaginal progesterone suppository daily and the second one received 250 mg of 17OHP-C intramuscular weekly after cerclage procedure until the end of 36 weeks. Patients were followed up to the end of delivery and the newborn until the first 28 d after delivery.

RESULTS

Gestational age at the time of birth in 17OHP-C group was significantly higher than vaginal progesterone group (p=.021). However, the incidence of preterm birth in both groups was not statistically significant (20.7% vs. 24.1%). Apgar scores, newborn birthweight, admission to neonatal intensive care unit (NICU), incidence of respiratory distress syndrome (RDS), sepsis, necrotizing enterocolitis (NEC), and, intraventricular hemorrhage (IVH), was similar in both groups. Adverse events were reported in 48.3% of patients in 17-OHP-C group, and 27.6% of patients in the vaginal progesterone group (p= .014).

CONCLUSIONS

Vaginal progesterone and 17OHP-C had similar results in terms of prevention of preterm birth and neonatal outcome. However, the adverse events associated with 17-OHP-C were higher than vaginal progesterone.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Prediction and Prevention of Spontaneous Preterm Birth: ACOG Practice Bulletin, Number 234

Preterm birth is among the most complex and important challenges in obstetrics. Despite decades of research and clinical advancement, approximately 1 in 10 newborns in the United States is born prematurely. These newborns account for approximately three-quarters of perinatal mortality and more than one half of long-term neonatal morbidity, at significant social and economic cost (1-3). Because preterm birth is the common endpoint for multiple pathophysiologic processes, detailed classification schemes for preterm birth phenotype and etiology have been proposed (4, 5). In general, approximately one half of preterm births follow spontaneous preterm labor, about a quarter follow preterm prelabor rupture of membranes (PPROM), and the remaining quarter of preterm births are intentional, medically indicated by maternal or fetal complications. There are pronounced racial disparities in the preterm birth rate in the United States. The purpose of this document is to describe the risk factors, screening methods, and treatments for preventing spontaneous preterm birth, and to review the evidence supporting their roles in clinical practice. This Practice Bulletin has been updated to include information on increasing rates of preterm birth in the United States, disparities in preterm birth rates, and approaches to screening and prevention strategies for patients at risk for spontaneous preterm birth.

Value of cervical electrical impedance spectroscopy to predict spontaneous preterm delivery in asymptomatic women: the ECCLIPPx prospective cohort study

OBJECTIVES

Preterm birth (PTB) accounts for two-thirds of deaths of structurally normal babies and is associated with substantial lifetime healthcare costs. Prevention of PTB remains limited by the modest accuracy of prediction methods, namely transvaginal ultrasound (TVS) cervical length (CL) measurement and quantitative cervicovaginal fetal fibronectin (FFN) estimation. We report the first substantive study detailing the predictive performance of a cervical probe device based on electrical impedance spectroscopy (EIS) for PTB - the EleCtriCaL Impedance Prediction of Preterm birth by spectroscopy of the cervix (ECCLIPPx) study. We aimed to compare the accuracy of cervical EIS-based prediction of spontaneous PTB with that of prediction using TVS-CL and FFN in asymptomatic women in the mid-trimester.

METHODS

We studied asymptomatic women with a singleton pregnancy at 20-22 weeks' and 26-28 weeks' gestation. EIS was performed using a Sheffield Mark 5.0 device that makes measurements in the frequency range 76 Hz to 625 kHz using a small probe housing tetrapolar electrodes. TVS-CL and FFN were also measured. The associations of cervical EIS, TVS-CL and FFN with spontaneous delivery before 37 weeks and before 32 weeks were determined by multivariate linear and non-linear logistic regression analysis. Areas under the receiver-operating-characteristics curves (AUC) plots of sensitivity against specificity were used to compare the predictive performance of all parameters, both in isolation and in combination.

RESULTS

Of the 365 asymptomatic women studied at 20-22 weeks who were not receiving treatment, 29 had spontaneous PTB, 14 had indicated PTB and 322 had term birth. At the higher frequencies assessed, cervical EIS predicted spontaneous PTB before 37 weeks with an AUC of 0.76 (95% CI, 0.71-0.81), compared with AUCs of 0.72 (95% CI, 0.66-0.76) for TVS-CL and 0.62 (95% CI, 0.56-0.72) for FFN. Combining all three assessments improved the prediction of spontaneous PTB before 37 weeks (AUC, 0.79 (95% CI, 0.74-0.83)) compared with TVS-CL and FFN alone. Incorporating a history of spontaneous PTB (defined as previous mid-trimester miscarriage or spontaneous PTB (14 to < 37 weeks)) into the cervical EIS prediction model improved the accuracy of prediction of spontaneous PTB before 37 weeks (AUC, 0.83 (95% CI, 0.78-0.87)) and before 32 weeks (AUC, 0.86 (95% CI, 0.82-0.90)).

CONCLUSIONS

Mid-trimester cervical EIS assessment predicts spontaneous PTB. Larger confirmatory studies investigating its potential clinical utility and to inform effective preventive interventions are required. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Patient and Provider Perspectives on Acceptability, Access, and Adherence to 17-Alpha-Hydroxyprogesterone Caproate for Preterm Birth Prevention

Background: Preterm birth (PTB) is a pressing maternal and child health issue with long-standing racial inequities in outcomes and care provision. 17-Alpha-hydroxyprogesterone caproate (17OHPC) has been one of few clinical interventions for recurrent PTB prevention. Little is known about the factors influencing successful administration and receipt of 17OHPC among mothers in the Medicaid program. Materials and Methods: We conducted individual semistructured interviews with 17OHPC-eligible pregnant women and obstetric providers from two academic medical centers in Philadelphia, PA. Patient participants were publicly insured, eligible for 17OHPC treatment, and purposively sampled as either (1) actively receiving treatment or (2) declining/discontinuing treatment. Providers had experience providing care to Medicaid-enrolled patients. Interview transcripts were coded and analyzed to identify themes related to treatment acceptability, access, and adherence. Results: Of the 17 patient participants, the mean age was 30 years. Ten providers (MDs, nurse practitioners, and registered nurses) were also interviewed. Factors facilitating 17OHPC uptake and adherence among patients included severity of prior PTB, provider counseling, and coordination among the clinic, pharmacy, and insurance. Pain was cited as the most significant barrier to 17OHPC for patients, while providers perceived social adversity and beliefs about patients' commitment to treatment to be primary patient barriers. For providers, clinical experience and practice guidelines contributed to their use of 17OHPC. Administrative complexity and coordination of services were the primary provider barrier to 17OHPC administration. Conclusions: Patient-provider communication is a primary driver of 17OHPC acceptability and adherence. Comprehensive patient-centered consultation may improve uptake of clinical therapies among pregnant women at high risk for PTB.

Preventing recurrent preterm birth with 125 mg of 17-alpha-hydroxyprogesterone caproate

AIM

There is strong evidence that weekly intramuscular (IM) injections of 250 mg of 17-alpha-hydroxyprogesterone caproate (17-OHPC) reduce the risk of recurrent preterm birth (PTB); however, whether a lower dose of 17-OHPC could reduce the risk of recurrent PTB remains unclear. This study aimed to assess whether 125 mg of 17-OHPC reduces recurrent PTB among women with a prior singleton spontaneous PTB and cervical length >25 mm.

METHODS

This retrospective cohort study at a tertiary-care medical center in Japan included women with a prior singleton spontaneous PTB between 20 and 36 weeks' gestation and cervical length >25 mm, between 2008 and 2018. Primary outcomes were PTB <37 and <34 weeks' gestation. We calculated the adjusted odds ratio (aOR) and 95% confidence interval (CI) using a multiple logistic regression model. Gestational age at delivery was compared using the Kaplan-Meier survival curve and log-rank test.

RESULTS

Overall, 173 women met the inclusion criteria. Eighty-four women received weekly injections of 125 mg of 17-OHPC, and 89 did not. Treatment with 125 mg of 17-OHPC significantly reduced the risk of recurrent spontaneous PTB <37 (aOR: 0.156 [95% CI: 0.049-0.497]) and <34 weeks' gestation (aOR: 0.156 [95% CI: 0.049-0.497]). The mean delivery gestational age was also significantly longer in the 17-OHPC group (log-rank p = 0.005).

CONCLUSIONS

In this study population, weekly IM injections of 125 mg of 17-OHPC reduced the risk of recurrent PTB <37 and <34 weeks' gestation.

Next generation strategies for preventing preterm birth

Preterm birth (PTB) is defined as delivery before 37 weeks of gestation. Globally, 15 million infants are born prematurely, putting these children at an increased risk of mortality and lifelong health challenges. Currently in the U.S., there is only one FDA approved therapy for the prevention of preterm birth. Makena is an intramuscular progestin injection given to women who have experienced a premature delivery in the past. Recently, however, Makena failed a confirmatory trial, resulting the Center for Drug Evaluation and Research's (CDER) recommendation for the FDA to withdrawal Makena's approval. This recommendation would leave clinicians with no therapeutic options for preventing PTB. Here, we outline recent interdisciplinary efforts involving physicians, pharmacologists, biologists, chemists, and engineers to understand risk factors associated with PTB, to define mechanisms that contribute to PTB, and to develop next generation therapies for preventing PTB. These advances have the potential to better identify women at risk for PTB, prevent the onset of premature labor, and, ultimately, save infant lives.

Landscape of Preterm Birth Therapeutics and a Path Forward

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

Pro-inflammatory signals induce 20α-HSD expression in myometrial cells: A key mechanism for local progesterone withdrawal

Metabolism of progesterone (P4) by the enzyme 20α hydroxysteroid dehydrogenase (20α‐HSD) in myometrial cells is postulated to be a mechanism for P4 withdrawal, which occurs concomitant to uterine inflammation (physiologic or infection‐induced) and associated activation of transcription factors: NF‐кB and AP‐1, common to term and preterm labour. We found that 20α‐HSD protein is significantly increased in human myometrium during term labour, and in mouse uterus during term and preterm labour. Treatment of human myometrial cells with the pro‐inflammatory mediators, lipopolysaccharide (LPS, mimicking infection) and 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA, mimicking inflammation), induced 20α‐HSD gene expression and increased 20α‐HSD protein abundance. LPS treatment decreased P4 release into the culture medium and resulted in up‐regulation of GJA1 in the hTERT‐HM cells. The NF‐кB /AP‐1 transcription factors mediated effects of LPS and TPA on 20α‐HSD gene transcription. Both pro‐inflammatory stimuli induced 20α‐HSD promoter activity in LPS/TPA‐treated cells which was significantly attenuated by inhibition of NF‐кB (JSH: 20 µM) or AP‐1 signalling (T5224: 10 µM). Deletion of NF‐кB consensus sites abrogated LPS‐mediated promoter induction, while removal of AP‐1 sites reversed the TPA‐mediated induction of 20α‐HSD promoter. We conclude that inflammatory stimuli (physiologic or pathologic) that activate NF‐кB or AP‐1 induce 20α‐HSD transcription and subsequent local P4 withdrawal resulting in up‐regulation of GJA1 and activation of myometrium that precedes labour.

Progesterone alters human cervical epithelial and stromal cell transition and migration: Implications in cervical remodeling during pregnancy and parturition

The cervix undergoes extensive remodeling throughout pregnancy and parturition. This process involves both ECM collagen degradation and cellular remodeling, which includes cell proliferation, transition and migration. Progesterone (P4) has been used clinically to delay cervical ripening and prevent preterm birth (PTB). However, the mechanisms by which progesterone affects cell transition and the migration of cervical epithelial and stromal cells are not yet fully known. In this study, we documented the role of a gestational level of P4 in the cellular transition (epithelial-mesenchymal transition [EMT] and mesenchymal-epithelial transition [MET]), cell migration, and inflammatory responses of endocervical epithelial cells (EEC) and cervical stromal cells (CSC). EEC and CSC were treated with LPS and P4 for 6 days. The epithelial:mesenchymal ratio (regular microscopy and cell shape index analysis), shift in intermediate filaments (immunofluorescence microscopy and western blot analyses for cytokeratin [CK]-18 and vimentin), adhesion molecules and transcription factors (western blot analyses for E-cadherin, N-cadherin and SNAIL), were used to determine growth characteristics and EMT and MET changes in EEC and CSC under the indicated conditions. To test cell remodeling, scratch assays followed by cellular analyses as mentioned above were performed. Inflammatory cytokines (interleukin-6 [IL-6], tumor necrosis factor α [TNFα]) and matrix metallopeptidase 9 (MMP9) were measured by ELISA. LPS promoted EMT (decreased cell shape index, decreased CK-18 and E-cadherin, increased vimentin, N-cadherin, and SNAIL), and increased IL-6 and MMP9 production by EEC. A gestational level of P4 prevented LPS-induced EMT in EEC and exhibited anti-inflammatory effect in both EEC and CSC. LPS slowed down wound healing in CSC but P4 treatment prevented the negative impact of LPS in CSC wound healing. These results may explain the cellular mechanisms by which P4 helps to stabilize the cervical epithelial barrier and preserve the mechanical and tensile strength of the cervical stromal layer, which are important in normal cervical remodeling processes during pregnancy.

Vaginal progesterone for prevention of preterm birth in asymptomatic high-risk women with a normal cervical length: a systematic review and meta-analysis protocol

BACKGROUND

Preterm birth (PTB) is estimated to affect 14.9 million babies globally every year. Global rates of PTB continue to increase from 9.8 to 10.6% over a 15-year period from 2000 to 2014. Vaginal progesterone is commonly used by clinicians as a prevention strategy, with recent evidence affirming the benefit of vaginal (micronised) progesterone to prevent PTB in women with a shortened cervix (< 25 mm). Given the low incidence of a short cervix at mid-gestation in high-risk populations further evidence is required. The objective of this review is to determine if vaginal progesterone reduces spontaneous preterm birth (sPTB) before 37 weeks in asymptomatic high-risk women with a singleton pregnancy with a normal mid-gestation cervical length.

METHODS

Studies will be sourced from MEDLINE, Embase and Cochrane Register of Trials (CENTRAL) from their inception onwards with the search terms 'progesterone' and 'preterm birth'. Studies will be screened and included if they assess vaginal progesterone compared to placebo in women with a normal cervical length. The primary outcome will be sPTB < 37 weeks, with secondary outcomes of sPTB < 34 weeks. Two independent reviewers will conduct study screening at abstract and full text level, data extraction and risk of bias assessment with disagreements resolved by an experienced researcher. The Mantel-Haenszel statistical method and random effects analysis model will be used to produce treatment effect odds ratios and corresponding 95% confidence intervals.

DISCUSSION

This review will assess the current body of evidence and provide clarity regarding the potential benefits and best practice of use of vaginal progesterone in asymptomatic women with high-risk singleton pregnancies and normal cervical length.

TRIAL REGISTRATION

PROSPERO CRD42020152051.

The long-term effect of prenatal progesterone treatment on child development, behaviour and health: a systematic review

BACKGROUND

Progesterone is widely used in prenatal care. However, long-term effects of prenatal progesterone treatment on child development are unclear.

OBJECTIVES

To evaluate long-term outcomes in children after prenatal progesterone treatment.

SEARCH STRATEGY

MEDLINE, Embase and Cochrane Central Register of Controlled Trials from inception to 24 May 2020.

SELECTION CRITERIA

Randomised controlled trials (RCTs) reporting outcomes in children born to women who received progesterone treatment (compared with placebo or another intervention) during any trimester in pregnancy.

DATA COLLECTION AND ANALYSIS

Two authors independently selected and extracted data. We used the Cochrane Risk of Bias tool for randomised trials and Quality In Prognosis Studies.

MAIN RESULTS

Of 388 papers, we included seven articles based on five RCTs, comprising 4222 measurements of children aged 6 months to 8 years. All studies compared progesterone to placebo in second and/or third trimester for the prevention of preterm birth. Meta-analysis (two studies, n = 890 children) showed no difference in neurodevelopment as assessed by the Bayley-III Cognitive Composite score at 2 years between children exposed to progesterone versus placebo (Standardised Mean Difference -0.04, 95% Confidence Interval -0.26 to 0.19), I2  = 22%. Heterogeneity prohibited additional meta-analyses. Other long-term outcomes showed no differences.

CONCLUSIONS

Our systematic review comprising a multitude of developmental measurements with a broad age range did not find evidence of benefit or harm in offspring prenatally exposed to progesterone treatment for the prevention of preterm birth. We identified an urgent need for follow-up studies of prenatal progesterone administration in early pregnancy and effects in offspring beyond early childhood.

TWEETABLE ABSTRACT

Progesterone to prevent preterm birth: no effect on child development. Outcomes after first trimester progesterone are unclear.

Utilization of hydroxyprogesterone caproate among pregnancies with live birth deliveries in the sentinel distributed database

BACKGROUND

The U.S. Food and Drug Administration (FDA) approved Makena^® (hydroxyprogesterone caproate [HPC] injection) in February 2011 for reducing the risk of preterm birth (PTB) in women with a singleton pregnancy who had a history of singleton spontaneous PTB (sPTB). Makena was approved under accelerated approval and required a postmarketing study to verify its clinical benefits. However, the postmarketing trial (PROLONG) failed to verify Makena's clinical benefit to neonates and substantiate its effect on reducing the risk of recurrent PTB. This study examined the utilization of HPC, along with another progestogen (vaginal progesterone) used to reduce the risk of sPTB during pregnancy, to inform the landscape of HPC use in the United States.

METHODS

We included pregnant women aged 10-54 years with a live birth delivery from 1 January, 2008 to 31 December, 2018 in the Sentinel Distributed Database (SDD). We examined the prevalence of injectable HPC (Makena and its generics), compounded HPC, and vaginal progesterone use during the second and third trimesters during the study period. We also assessed the proportion of these HPC-exposed pregnancies with obstetrical conditions of interest as potential reasons for use: (1) history of preterm delivery; (2) cervical shortening in the current pregnancy; and (3) preterm labor in the current pregnancy.

RESULTS

We identified a total of 3,445,739 live-birth pregnancies (among 2.9 million women) between 2008 and 2018 in the SDD. Of these pregnancies, 6.5 per 1,000 pregnancies used injectable HPC, 2.3 per 1,000 pregnancies used compounded HPC, and 1.5 per 1,000 pregnancies used vaginal progesterone during the second and/or third trimesters. The yearly uptakeof pregnancies with injectable HPC use increased during the study period from 2.1 per 1,000 pregnancies in 2012 to 12.6 per 1,000 pregnancies in 2018; use of compounded HPC decreased from 3.3 per 1,000 pregnancies to 0.25 per 1,000 pregnancies over the same period. Of 16,524 pregnancies with injectable HPC use, 12,054 (73%) had at least one related obstetrical condition, including 6,439 (39%) with a recorded history of preterm delivery. In addition, 4,665 (28%) had a PTB recorded as the outcome for the current pregnancy.

CONCLUSIONS

We found modest use of HPC during the second and/or third trimesters among all live-birth pregnancies in SDD. The majority of pregnancies with injectable HPC use had at least one of three obstetrical indications of interest recorded before or during the pregnancy.

17 Alpha-hydroxyprogesterone caproate use in a rural state

BACKGROUND

17 alpha-hydroxyprogesterone caproate (17OHP) is used to reduce the recurrent risk of preterm delivery in women with a history of preterm delivery. Meis et al. conducted a double-blind placebo controlled trial to evaluate the effectiveness of 17OHP and observed a significant reduction in the risk of recurrent preterm delivery. The FDA granted 17OHP a conditional approval on 2011. A second study observed that 17OHP did not decrease the risk of a recurrent preterm delivery. Criticism of the second study derived from a dissimilarity of the study population.

OBJECTIVE

Our investigation examined the effectiveness of 17OHP in women with a prior preterm delivery in a rural US state with a patient population similar to the original Meis trial.

STUDY DESIGN

17OHP became largely unavailable (due to cost and local pharmacies no longer compounding 17 OHP) and the University of Arkansas for Medical Sciences, Department of Health, and Arkansas Medicaid co-operated to make 17OHP available to women with a prior PTB in our state. This study was a retrospective review of the 17OHP that was offered to women with a prior preterm delivery. For our retrospective review, logistic regression was used on cases of prior preterm delivery between January 2014 and December of 2018 to examine the relationship between 17OHP injections and preterm delivery.

RESULTS

A total of 268 women were analyzed for this review. They were divided into three groups: 0 injections, 1-10 injections, and > 10 injections. We found no relationship between 17OHP injections with preterm delivery.

CONCLUSION

Although our patient population was similar to that of the original Meis trial, our results were more similar to the second study by Blackwell.

17-alpha hydroxyprogesterone caproate and risk for venous thromboembolism during pregnancy

INTRODUCTION

17-alpha hydroxyprogesterone caproate (17 P) is a progestin commonly used during pregnancy to reduce risk of recurrent preterm birth. History of thromboembolism is a contraindication to 17 P and the package insert for 17 P recommends discontinuation in the setting of an acute VTE event. The objective of this study was to determine whether 17 P is associated with increased risk of VTE.

STUDY DESIGN

The MarketScan claims database was used to perform a retrospective cohort of women who underwent delivery from 4/2008 to 1/2015. We identified women who received 17 P during pregnancy based on pharmacy benefits. Risk for VTE including deep vein thrombosis, pulmonary embolism, or both was stratified based on the presence or absence of 17 P pharmacy receipt. Both antenatal and delivery hospitalization VTE events were asceratined and these periods were analyzed individually. Relative risk (RR) was determined based on 17 P receipt.

RESULTS

Among 4,775,667 delivery hospitalizations, 18,745 women received 17 P. Among women who did not receive 17 P, 0.52% of women (n = 24,529) had a VTE diagnosis compared to 0.61% (n = 114) receiving 17 P (RR 1.18, 95% CI 0.98-1.42). Comparing VTE events (i) during the antenatal period and (ii) during delivery hospitalizations, risks did not differ significantly for patients receiving 17 P. When risk was restricted to the cohort of patients without a diagnosis of a prior VTE event, 0.30% of women (n = 56) receiving 17 P were diagnosed with an event versus 0.28% of women (n = 13,427) not receiving 17 P (RR 1.07, 95% 0.82-1.39).

DISCUSSION

No significant increased risk for VTE was noted with 17 P receipt. While new research has led to reconsideration of clinical use of 17 P for preterm birth prevention based on efficacy, findings from this analysis do not support major risk for thrombosis.

Risk Factors Associated with Preterm Delivery in Singleton Pregnancy in a Tertiary Care Hospital in South India: A Case Control Study

Background

Preterm delivery is a major obstetric complication and a leading cause of neonatal mortality and morbidity. It is also associated with significant costs in terms of psychological and financial hardship, to the families.

Objective

The primary objective of this study was to determine the risk factors associated with all preterm deliveries in singleton pregnancy in a tertiary care hospital and the secondary objective was to determine the fetal outcomes among women with preterm delivery.

Materials and Methods

A case control study was conducted between January 2019 and June 2019 in the Department of Obstetrics and Gynecology of a tertiary care center in Central Kerala, India. Women who delivered before 37 completed weeks of gestation were taken as cases and those who delivered at or after 37 weeks were considered as controls in a 1:1 ratio, approximately. Data regarding 191 cases and 200 controls were taken from delivery room records of the years 2016 to 2018 with the help of a predesigned checklist. Univariate and multivariate analysis were done to determine the magnitude of association between the exposure factors and preterm delivery.

Results

The mean age of study participants among the cases was 29.3 ± 5.1 years and controls was 28.1 ± 4.4. Pregnancy induced hypertension (aOR = 14.60; 95% CI 4.8, 44.1; p<0.001), abnormal amniotic fluid volume (aOR = 10.68; 95% CI 3.46, 32.98; p<0.001), premature rupture of membranes (PROM) (aOR = 10.27; 95% CI 4.82, 21.86; p<0.001), previous history of preterm delivery (aOR = 4.12; 95% CI 1.22, 13.85; p<0.002), history of urinary tract infection (UTI) during pregnancy (aOR = 3.67; 95% CI 1.39, 9.68; p<0.002), systemic diseases (aOR = 2.78; 95% CI 1.28, 6.39; p<0.001), anaemia (aOR = 2.54; 95% CI 1.28, 5.03; p<0.004) were found to be the independent risk factors for preterm delivery. On analyzing the fetal outcomes, the average birth weight of preterm babies was 2 ± 0.6 kg compared to 3.1kg among term babies.

Conclusion

Early detection and adequate treatment of various conditions like anaemia, pregnancy induced hypertension, UTI and systemic illness can help in reduction of the prevalence of preterm delivery.

Can We Predict Preterm Delivery Based on the Previous Pregnancy?

(1) Background: Preterm deliveries (PTD, <37 gestational weeks) which occur in 5–18% of deliveries across the world, are associated with immediate and long-term offspring morbidity, as well as high costs to health systems. Our aim was to identify risk factors during the first pregnancy ending at term for PTD in the subsequent pregnancy. (2) Methods: A retrospective population- based nested case−control study was conducted, including all women with two first singleton consecutive deliveries. Women with PTD in the first pregnancy were excluded. Characteristics and complications of the first pregnancy were compared among cases, defined as women with PTD in their second pregnancy, and the controls, defined as women delivering at term in their second pregnancy. A multivariable logistic regression model was used to study the association between pregnancy complications (in the first pregnancy) and PTD (in the subsequent pregnancy), while adjusting for maternal age and the interpregnancy interval. (3) Results: A total of 39,780 women were included in the study, 5.2% (n = 2088) had PTD in their second pregnancy. Women with PTD, as compared to controls (i.e., delivered at term in second pregnancy), were more likely to have the following complications in their first pregnancy: perinatal mortality (0.4% vs. 1.0%), small for gestational age (12.4% vs. 8.1%), and preeclampsia (7.6% vs. 5.7%). In the multivariable model, after adjusting for maternal age, interpregnancy interval and co-morbidities, having any one of these first pregnancy complications was independently associated with an increased risk for PTD (adjusted OR = 1.44; 95%CI 1.28–1.62), and the risk was greater if two or more complications were diagnosed (adjusted OR = 2.09; 95%CI 1.47–3.00). These complications were also risk factors for early PTD (<34 gestational weeks), PTD with a systematic infectious disease in the background, and possibly with spontaneous PTD. (4) Conclusions: First pregnancy complications are associated with an increased risk for PTD in the subsequent pregnancy. First pregnancy, although ending at term, may serve as a window of opportunity to identify women at risk for future PTD.

Effect of a Nonoptimal Cervicovaginal Microbiota and Psychosocial Stress on Recurrent Spontaneous Preterm Birth

OBJECTIVE

While select cervicovaginal microbiota and psychosocial factors have been associated with spontaneous preterm birth, their effect on the risk of recurrence remains unclear. It is also unknown whether psychosocial factors amplify underlying biologic risk. This study sought to determine the effect of nonoptimal cervicovaginal microbiota and perceived stress on the risk of recurrent spontaneous preterm birth.

STUDY DESIGN

This was a secondary analysis of a prospective pregnancy cohort, Motherhood and Microbiome. The Cohen's Perceived Stress Scale (PSS-14) was administered and cervical swabs were obtained between 16 and 20 weeks of gestation. PSS-14 scores ≥30 reflected high perceived stress. We analyzed cervicovaginal microbiota using 16S rRNA sequencing and classified microbial communities into community state types (CSTs). CST IV is a nonoptimal cervicovaginal microbial community characterized by anaerobes and a lack of Lactobacillus. The final cohort included a predominantly non-Hispanic Black population of women with prior spontaneous preterm birth who had recurrent spontaneous preterm birth or term birth and had stress measurements (n = 181). A subanalysis was performed in the subset of these women with cervicovaginal microbiota data (n = 74). Multivariable logistic regression modeled adjusted associations between CST IV and recurrent spontaneous preterm birth, high stress and recurrent spontaneous preterm birth, as well as high stress and CST IV.

RESULTS

Among the 181 women with prior spontaneous preterm birth, 45 (24.9%) had high perceived stress. We did not detect a significant association between high stress and recurrent spontaneous preterm birth (adjusted odds ratio [aOR] 1.67, 95% confidence interval [CI]: 0.73-3.85). Among the 74 women with prior spontaneous preterm birth and cervicovaginal microbiota analyzed, 29 (39.2%) had CST IV; this proportion differed significantly among women with recurrent spontaneous preterm birth (51.4%) compared with women with term birth (28.2%) (p = 0.04). In models adjusted for race and marital status, the association between CST IV and recurrent spontaneous preterm birth persisted (aOR 3.58, 95% CI: 1.25-10.24). There was no significant interaction between stress and CST IV on the odds of spontaneous preterm birth (p = 0.328). When both stress and CST IV were introduced into the model, their associations with recurrent spontaneous preterm birth were slightly stronger than when they were in the model alone. The aOR for stress with recurrent spontaneous preterm birth was 2.02 (95% CI: 0.61-6.71) and for CST IV the aOR was 3.83 (95% CI: 1.30-11.33). Compared to women with neither of the two exposures, women with both high stress and CST IV had the highest odds of recurrent spontaneous preterm birth (aOR = 6.01, 95% CI: 1.002-36.03).

CONCLUSION

Among a predominantly non-Hispanic Black cohort of women with a prior spontaneous preterm birth, a nonoptimal cervicovaginal microbiota is associated with increased odds of recurrent spontaneous preterm birth. Adjustment for perceived stress may amplify associations between CST IV and recurrent spontaneous preterm birth. Identification of modifiable social or behavioral factors may unveil novel nonpharmacologic interventions to decrease recurrent spontaneous preterm birth among women with underlying biologic risk.

KEY POINTS

· CST IV, a nonoptimal microbiota, is associated with increased odds of recurrent spontaneous preterm birth.. · Adjustment for perceived stress amplified associations between CST IV and recurrent spontaneous preterm birth.. · Identification of modifiable psychosocial factors may unveil novel nonpharmacologic interventions to decrease recurrent preterm birth..

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

BACKGROUND

Preterm birth is a global health priority. Using a progestogen during high-risk pregnancy could reduce preterm birth and adverse neonatal outcomes.

METHODS

We did a systematic review of randomised trials comparing vaginal progesterone, intramuscular 17-hydroxyprogesterone caproate (17-OHPC), or oral progesterone with control, or with each other, in asymptomatic women at risk of preterm birth. We identified published and unpublished trials that completed primary data collection before July 30, 2016, (12 months before data collection began), by searching MEDLINE, Embase, CINAHL, the Maternity and Infant Care Database, and relevant trial registers between inception and July 30, 2019. Trials of progestogen to prevent early miscarriage or immediately-threatened preterm birth were excluded. Individual participant data were requested from investigators of eligible trials. Outcomes included preterm birth, early preterm birth, and mid-trimester birth. Adverse neonatal sequelae associated with early births were assessed using a composite of serious neonatal complications, and individually. Adverse maternal outcomes were investigated as a composite and individually. Individual participant data were checked and risk of bias assessed independently by two researchers. Primary meta-analyses used one-stage generalised linear mixed models that incorporated random effects to allow for heterogeneity across trials. This meta-analysis is registered with PROSPERO, CRD42017068299.

FINDINGS

Initial searches identified 47 eligible trials. Individual participant data were available for 30 of these trials. An additional trial was later included in a targeted update. Data were therefore available from a total of 31 trials (11 644 women and 16185 offspring). Trials in singleton pregnancies included mostly women with previous spontaneous preterm birth or short cervix. Preterm birth before 34 weeks was reduced in such women who received vaginal progesterone (nine trials, 3769 women; relative risk [RR] 0·78, 95% CI 0·68-0·90), 17-OHPC (five trials, 3053 women; 0·83, 0·68-1·01), and oral progesterone (two trials, 181 women; 0·60, 0·40-0·90). Results for other birth and neonatal outcomes were consistently favourable, but less certain. A possible increase in maternal complications was suggested, but this was uncertain. We identified no consistent evidence of treatment interaction with any participant characteristics examined, although analyses within subpopulations questioned efficacy in women who did not have a short cervix. Trials in multifetal pregnancies mostly included women without additional risk factors. For twins, vaginal progesterone did not reduce preterm birth before 34 weeks (eight trials, 2046 women: RR 1·01, 95% CI 0·84-1·20) nor did 17-OHPC for twins or triplets (eight trials, 2253 women: 1·04, 0·92-1·18). Preterm premature rupture of membranes was increased with 17-OHPC exposure in multifetal gestations (rupture <34 weeks RR 1·59, 95% CI 1·15-2·22), but we found no consistent evidence of benefit or harm for other outcomes with either vaginal progesterone or 17-OHPC.

INTERPRETATION

Vaginal progesterone and 17-OHPC both reduced birth before 34 weeks' gestation in high-risk singleton pregnancies. Given increased underlying risk, absolute risk reduction is greater for women with a short cervix, hence treatment might be most useful for these women. Evidence for oral progesterone is insufficient to support its use. Shared decision making with woman with high-risk singleton pregnancies should discuss an individual's risk, potential benefits, harms and practicalities of intervention. Treatment of unselected multifetal pregnancies with a progestogen is not supported by the evidence.

FUNDING

Patient-Centered Outcomes Research Institute.

Cytokine profiling: variation in immune modulation with preterm birth vs. uncomplicated term birth identifies pivotal signals in pathogenesis of preterm birth

OBJECTIVES

To assess deviations in longitudinally measured cytokines with preterm birth (PTB).

METHODS

Prospective longitudinal study targeting 80 subjects. Phlebotomy specimens for broad panel of cytokine analysis were obtained at three time (T) intervals: first trimester (T1: 8-14 weeks' gestation), second trimester (T2: 18-22 weeks' gestation), and third trimester (T3: 28-32 weeks' gestation). Important demographics and outcomes were tracked. Data were stratified and the target groups were analyzed as follows: "Uncomplicated" (delivered ≥37 weeks) or "Preterm Birth" (<37 weeks). Generalized Linear Modeling determined rate of change T1-T3 by outcome.

RESULTS

Complete data replete with phlebotomy at all three visits were obtained on 80 women. Birth outcomes were as follows: 11 Uncomplicated Term Birth (UTB), 28 PTB, 4 low birth weight (LBW), 16 OB complications (OBC), 11 current infections (IFN), and 10 mixed complications (MC=2 or more of the above). 28 PTB were compared to 11 uncomplicated term deliveries. In both groups, T helper type 1 (TH1) cytokine (IL-1β), pleiotrophic pro-inflammatory cytokine (IL-6), and counter-regulatory cytokine (IL-10) responses decreased over gestation, but rates of change in IL-1β, IL-6, and IL-10 were significantly different. Stratification of women by smoking status additionally demonstrated significant variance in immune status over the course of pregnancy.

CONCLUSIONS

Women delivering PTB demonstrated significant differences in cytokine trajectory over pregnancy; these data further validate key role played by immune regulation in directing pregnancy outcome. Likewise, smoking impacts longitudinal trajectory of cytokines over pregnancy.

Progesterone receptor isoform B regulates the Oxtr-Plcl2-Trpc3 pathway to suppress uterine contractility

Uterine contractile dysfunction leads to pregnancy complications such as preterm birth and labor dystocia. In humans, it is hypothesized that progesterone receptor isoform PGR-B promotes a relaxed state of the myometrium, and PGR-A facilitates uterine contraction. This hypothesis was tested in vivo using transgenic mouse models that overexpress PGR-A or PGR-B in smooth muscle cells. Elevated PGR-B abundance results in a marked increase in gestational length compared to control mice (21.1 versus 19.1 d respectively, P < 0.05). In both ex vivo and in vivo experiments, PGR-B overexpression leads to prolonged labor, a significant decrease in uterine contractility, and a high incidence of labor dystocia. Conversely, PGR-A overexpression leads to an increase in uterine contractility without a change in gestational length. Uterine RNA sequencing at midpregnancy identified 1,174 isoform-specific downstream targets and 424 genes that are commonly regulated by both PGR isoforms. Gene signature analyses further reveal PGR-B for muscle relaxation and PGR-A being proinflammatory. Elevated PGR-B abundance reduces Oxtr and Trpc3 and increases Plcl2 expression, which manifests a genetic profile of compromised oxytocin signaling. Functionally, both endogenous PLCL2 and its paralog PLCL1 can attenuate uterine muscle cell contraction in a CRISPRa-based assay system. These findings provide in vivo support that PGR isoform levels determine distinct transcriptomic landscapes and pathways in myometrial function and labor, which may help further the understanding of abnormal uterine function in the clinical setting.

Sex differences in dopamine innervation and microglia are altered by synthetic progestin in neonatal medial prefrontal cortex

The synthetic progestin 17-α-hydroxyprogesterone caproate (17-OHPC) is commonly prescribed to pregnant women with a history of preterm delivery, despite little evidence of efficacy. The timing of 17-OHPC administration coincides with fetal mesocortical dopamine pathway development, yet the potential effects on cortical development and cognition are almost unknown. In rodent models, exposure to 17-OHPC significantly increased dopaminergic innervation of the medial prefrontal cortex (mPFC), an aberrant pattern of connectivity that may underlie deficits in cognitive flexibility observed in adulthood. In the present study, tyrosine hydroxylase (TH) immunoreactivity was used to determine whether 17-OHPC altered dopaminergic innervation of the mPFC during a neonatal period of synaptogenesis in males and females. Although there were no differences in the amount of TH-immunoreactive (-IR) fibres, there was a sex difference in TH-IR fibre distribution in deep layers of the prelimbic area (PL) mPFC; males had a narrower pattern of dopaminergic innervation than females. 17-OHPC exposure abolished these sex-specific patterns, such that 17-OHPC females had a narrower pattern in the PL than control females. In the infralimbic mPFC (IL), 17-OHPC males had a broader pattern of distribution of TH-immunoreactivity than control males with no differences in the amount of TH-IR fibres. 17-OHPC also created a sex difference in which males had a lower TH-IR fibre density than females. We also examined microglia, brain macrophages that play a key role in sculpting dopaminergic axon outgrowth in development, using phenotype as an indirect measure of microglial activity. Females had a greater number of reactive stout microglia compared to males in the PL, and males had more active round microglia than females in the IL. 17-OHPC treatment abolished the sex differences in both regions. These findings demonstrate that developmental exposure to 17-OHPC can exert differential effects in males and females and may diminish sex differences in cortical maturation.

Evaluation of the efficacy of vaginal progesterone in preventing preterm birth after abdominal trachelectomy

OBJECTIVE

To determine whether vaginal progesterone (VP) reduces the rate of preterm birth in pregnant women after abdominal trachelectomy (AT) for early-stage cervical cancer STUDY DESIGN: This is an interventional study with a historical cohort. For the interventional study participants who had singleton pregnancies after AT between October 2016 and September 2020, the administration of vaginal progesterone was started between 16⁺ and 19⁺⁶ weeks of gestation and discontinued at 34 weeks of gestation or at the time of delivery, rupture of membranes, or massive uterine bleeding. We investigated obstetric and neonatal outcomes among the study participants and compared them with outcomes of the historical control group participants, included women with singleton pregnancies after AT who were managed without VP at our institution between January 2007 and September 2016, using Fisher's exact test and the Mann-Whitney U test The main outcomes were the gestational age at delivery and incidence of preterm birth before 37 weeks and 34 weeks of gestation.

RESULT

Twelve pregnancies in ten women were included in the VP group. In contrast, 19 pregnancies in 17 women were included in the historical control group. The incidence of preterm birth at <37 weeks was 10/12 (83 %) in the VP group and 11/19 (58 %) in the control group. The incidence of preterm birth at <34 weeks was 6/12 (50 %) in the VP group and 9/19 (48 %) in the control group. The incidence of preterm birth in the two groups was similar, and the difference between the two groups was not statistically significant.

CONCLUSION

The administration of vaginal progesterone did not reduce the rate of preterm birth among pregnant women after AT.

The Short Cervix: A Critical Analysis of Diagnosis and Treatment

A short cervix in the second trimester is a significant risk factor for spontaneous preterm birth, preterm prelabor rupture of membranes, and subsequent adverse perinatal outcome. The pathophysiology is complex and multifactorial with inflammatory and/or infectious processes often involved. Biomarkers have been developed in an effort to predict preterm birth with varying degrees of success. The treatment options of cerclage, progesterone, pessary, and combination therapy are reviewed. Evidence-based protocols are summarized for singleton and multiple gestation.

Using Supervised Learning Methods to Develop a List of Prescription Medications of Greatest Concern during Pregnancy

INTRODUCTION

Women and healthcare providers lack adequate information on medication safety during pregnancy. While resources describing fetal risk are available, information is provided in multiple locations, often with subjective assessments of available data. We developed a list of medications of greatest concern during pregnancy to help healthcare providers counsel reproductive-aged and pregnant women.

METHODS

Prescription drug labels submitted to the U.S. Food and Drug Administration with information in the Teratogen Information System (TERIS) and/or Drugs in Pregnancy and Lactation by Briggs & Freeman were included (N = 1,186 medications; 766 from three data sources, 420 from two). We used two supervised learning methods ('support vector machine' and 'sentiment analysis') to create prediction models based on narrative descriptions of fetal risk. Two models were created per data source. Our final list included medications categorized as 'high' risk in at least four of six models (if three data sources) or three of four models (if two data sources).

RESULTS

We classified 80 prescription medications as being of greatest concern during pregnancy; over half were antineoplastic agents (n = 24), angiotensin converting enzyme inhibitors (n = 10), angiotensin II receptor antagonists (n = 8), and anticonvulsants (n = 7).

DISCUSSION

This evidence-based list could be a useful tool for healthcare providers counseling reproductive-aged and pregnant women about medication use during pregnancy. However, providers and patients may find it helpful to weigh the risks and benefits of any pharmacologic treatment for both pregnant women and the fetus when managing medical conditions before and during pregnancy.

Obesity-induced excess of 17-hydroxyprogesterone promotes hyperglycemia through activation of glucocorticoid receptor

Type 2 diabetes mellitus (T2DM) has become an expanding global public health problem. Although the glucocorticoid receptor (GR) is an important regulator of glucose metabolism, the relationship between circulating glucocorticoids (GCs) and the features of T2DM remains controversial. Here, we show that 17-hydroxyprogesterone (17-OHP), an intermediate steroid in the biosynthetic pathway that converts cholesterol to cortisol, binds to and stimulates the transcriptional activity of GR. Hepatic 17-OHP concentrations are increased in diabetic mice and patients due to aberrantly increased expression of Cyp17A1. Systemic administration of 17-OHP or overexpression of Cyp17A1 in the livers of lean mice promoted the pathogenesis of hyperglycemia and insulin resistance, whereas knockdown of Cyp17A1 abrogated metabolic disorders in obese mice. Therefore, our results identify a Cyp17A1/17-OHP/GR-dependent pathway in the liver that mediates obesity-induced hyperglycemia, suggesting that selectively targeting hepatic Cyp17A1 may provide a therapeutic avenue for treating T2DM.

The Importance of Clinical Presentation in Risk and Management of Recurrent Preterm Birth

OBJECTIVE

This study aimed to compare the risk of recurrent spontaneous preterm birth (sPTB), as well as cerclage efficacy, between groups stratified by phenotype of the index sPTB.

STUDY DESIGN

This is a retrospective cohort study of women with a history of sPTB. Included were women with a history of singleton sPTB who received progesterone in a subsequent pregnancy. Multifetal gestations and abdominal cerclage were excluded. Exposure groups were based upon the presenting symptom that preceded their first sPTB and included painless cervical dilation (PCD), preterm premature rupture of membranes (PPROM), and painful dilation (preterm labor [PTL]). Primary outcome was delivery <34 weeks in a subsequent pregnancy. Secondary outcomes included delivery <28 and <37 weeks. Rates were compared using the Chi-square test. Multivariable Poisson regression was used to adjust for confounders.

RESULTS

A total of 723 women were included. A total of 114 (16%) presented with PCD, 305 (42%) with PPROM, and 304 (42%) with PTL in their first sPTB. Cerclage in subsequent pregnancy was highest in the PCD group (42%) when compared with the PPROM (16%) and PTL (12%) groups. Rates of sPTB <34 and 37 weeks were similar among the groups. After adjusting for confounders, PCD was found to significantly increase the risk of recurrent sPTB <28 weeks (incidence rate ratio: 3.46 [1.09-11.0]; p = 0.04). Of the 121 women who underwent cerclage, there were no significant differences in rates of sPTB between the clinical presentation groups.

CONCLUSION

PCD as a specific phenotype of sPTB impacts recurrence of delivery before 28 weeks, but not at later gestational ages. In contrast, there was no significant association between clinical presentation of index sPTB and gestational latency in women who also underwent cerclage placement in a subsequent pregnancy. Our data suggest that clinical presentation is important with regards to recurrence of early sPTB, but not sPTB at later gestational ages.

KEY POINTS

· Phenotype is critical to understanding PTB.. · Phenotype is associated with recurrent PTB.. · Painless dilation is associated with recurrent PTB..

A chronicle of the 17-alpha hydroxyprogesterone caproate story to prevent recurrent preterm birth

Preterm birth is a substantial public health concern. In 2019, the US preterm birth rate was 10.23%, which is the fifth straight year of increase in this rate. Moreover, preterm birth accounts for approximately 1 in 6 infant deaths, and surviving children often suffer developmental delay or long-term neurologic impairment. Although the burden of preterm birth is clear, identifying strategies to reduce preterm birth has been challenging. On October 29, 2019, a US Food and Drug Administration advisory committee voted 9 vs 7 to withdraw interim accelerated approval of 17-alpha hydroxyprogesterone caproate for preventing recurrent preterm birth because the called for a confirmatory trial, known as the Prevention of Preterm Birth in Women With a Previous Singleton Spontaneous Preterm Delivery trial, was not confirmatory. The Prevention of Preterm Birth in Women With a Previous Singleton Spontaneous Preterm Delivery trial included subjects enrolled in the United States and Canada to ensure that at least 10% of patients would be from North America; however, this trial took 9 years to complete and did not demonstrate significant treatment effects in the 2 primary outcomes of interest. Delivery before 35 weeks' gestation occurred in 122 of 1130 women (11%) given 17-alpha hydroxyprogesterone caproate compared with 66 of 578 women (11.5%) given placebo (relative risk, 0.95; 95% confidence interval, 0.71-1.26; P=.72). Similarly, the coprimary outcome neonatal composite index occurred in 61 of 1093 women (5.6%) given 17-alpha hydroxyprogesterone caproate compared with 28 of 559 women (5.0%) given placebo (relative risk, 1.12; 95% confidence interval, 0.68-1.61; P=.73). There was also a lack of efficacy for 17-alpha hydroxyprogesterone caproate treatment in the analysis of a variety of secondary outcomes. Like the Maternal-Fetal Medicine Units Network trial, the Prevention of Preterm Birth in Women With a Previous Singleton Spontaneous Preterm Delivery trial was also flawed. Importantly, the Maternal-Fetal Medicine Unit Network trial was the sole justification for treating women in the United States with 17-alpha hydroxyprogesterone caproate for nearly 2 decades. Currently, despite more than half a century, 17-alpha hydroxyprogesterone caproate still has not been found to be clearly effective. In this context, how does the advising physician dependent on scientific evidence advise a patient that 17-alpha hydroxyprogesterone caproate is effective when the evidence to support this advice has repeatedly been found to be inadequate? This clinical opinion is a critical appraisal of the 2 randomized trials examining the efficacy of 17-alpha hydroxyprogesterone caproate to prevent recurrent preterm birth and a chronicle of events in the regulatory process of drug approval to help answer this question. With this examination, these events illustrate the complexity of pharmaceutical regulations in the era of accelerated Food and Drug Administration approval and characterize the financial impact and influence in medicine. In this report, we also emphasize the value of observational studies in contemporary practice and identify other examples in medicine where accelerated Food and Drug Administration approval has been withdrawn. Importantly, the themes of the 17-alpha hydroxyprogesterone caproate story are not limited to obstetrics. It can also serve as a microcosm of issues within the US healthcare system, which ultimately contributes to the high cost of healthcare. In our opinion, the answer to the question is clear-the facts speak for themselves-and we believe 17-alpha hydroxyprogesterone caproate should not be endorsed for use to prevent recurrent preterm birth in the United States.

17-Hydroxyprogesterone Caproate for the Prevention of Recurrent Preterm Birth - A Systematic Review and Meta-analysis Taking into Account the PROLONG Trial

Background Prior spontaneous preterm birth is a strong risk factor for the recurrence of spontaneous preterm birth in a subsequent pregnancy and has been evaluated in prevention studies using progesterone (natural progesterone administered orally or vaginally, and 17-hydroxyprogesterone caproate [17-OHPC]) as a selection criterion. Based on the findings of a randomized, placebo-controlled study, 17-OHPC was approved for use in 2011 by the Food and Drug Administration in the USA for the prevention of recurrent preterm birth. The approval was granted with qualification that a subsequent confirmatory study would need to be carried out, the results of which have just been published (PROLONG trial). Method A systematic literature search for the period from 1970 to April 2020 using the search terms "preterm birth" and "17-OHPC" or "progesterone" was carried out. Only randomized, placebo-controlled studies of women with singleton pregnancies who received 17-OHPC to prevent recurrent preterm birth were included in the subsequent meta-analysis. The relative risk and associated 95% confidence intervals were calculated. The heterogeneity between studies was evaluated with I ² statistics. Results In addition to the original study used for the approval and the PROLONG trial, only one other study was found which met the inclusion criteria (total number of patients: 2221). With considerable heterogeneity between the studies, particularly with respect to the risk factors for preterm birth, the comparison between 17-OHPC and placebo showed no significant reduction in preterm birth rates before 37, 35 and 32 weeks of gestation and no significant differences with regard to the prevalence of miscarriage before 20 weeks of gestation or fetal deaths (antepartum or intrapartum) after 20 weeks of gestation and neonatal morbidity. Conclusion Based on the currently available data, 17-OHPC cannot be recommended for the prevention of recurrent preterm birth. Further randomized, placebo-controlled studies with clearly defined, comparable risk factors are required to identify the group of pregnant women which could benefit from the use of 17-OHPC to prevent preterm birth.

Delivering equity: preterm birth by socioeconomic class before and after coverage of 17-hydroxyprogesterone caproate

OBJECTIVE

We compare the preterm birth rate across socioeconomic strata in Michigan before and after the decision by Michigan Medicaid to provide coverage for 17-hydroxyprogesterone caproate (17-OHP), a costly medication for recurrent preterm birth prevention.

STUDY DESIGN

We retrospectively analyzed births recorded in the Michigan Department of Health & Human Services database from 2008-2016, comparing the rate of preterm birth stratified by standardized US Census Bureau socioeconomic levels (affluent, higher-middle class, lower-middle class, and poverty) across three time periods: pre-Federal Drug Administration approval of 17-OHP (2008-2011), pre-Medicaid coverage (2012-2014), and post-Medicaid coverage (2015-2016).

RESULTS

Of 1,034,901 total live births, 10% (N = 103,869) were premature. An ANOVA with post-hoc testing showed the preterm birth rate was highest for those living in poverty, lower for the lower-middle class, and lowest for the collective higher-middle and affluent classes. The preterm birth rate dropped for all classes after Michigan Medicaid began paying for 17-OHP, but inter-class gaps remained.

CONCLUSION

Extended financial coverage for 17-OHP may have contributed to modest decreases in preterm birth rates, but this policy did not equalize outcomes between those with disparate resources.

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

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

Current Approaches to Risk Assessment and Prevention of Preterm Birth-A Continuing Public Health Crisis

Background: Preterm birth remains a major cause of neonatal morbidity and mortality. Several potential pathways and pathophysiologic processes can lead to preterm birth, complicating efforts to screen for the risk of preterm birth and making implementation of prevention strategies difficult.

Methods: Based on a review of the literature, this article addresses screening strategies for preterm birth risk stratification and interventions for preterm birth prevention.

Results: In women with a history of a prior spontaneous preterm birth, cervical cerclage placement in the setting of short cervix reduces the rate of recurrent spontaneous preterm birth. Weekly injections of 17-hydroxyprogesterone caproate (17-P) have been used as standard treatment for the prevention of recurrent preterm birth since 2011. However, results of a replication study of 17-P published in 2020 have raised questions regarding the effectiveness of this drug, and it is under review by the US Food and Drug Administration. Among women with no history of preterm birth, cervical length appears to be the best predictor of risk for preterm birth in asymptomatic women. In women with a cervical length <25 mm, vaginal progesterone has been demonstrated to reduce the risk of preterm birth.

Conclusion: Strategies including cervical length screening, vaginal progesterone administration, cervical cerclage placement, and, potentially, 17-P administration may help reduce rates of preterm birth when used in the appropriate patient populations. Development of protocols for patient evaluation and risk stratification will help identify patients at highest risk for preterm birth and allow use of the best available therapeutic interventions.

Maternal metabolic profiling to assess fetal gestational age and predict preterm delivery: a two-centre retrospective cohort study in the US

OBJECTIVES

The aim of this study was to develop a single blood test that could determine gestational age and estimate the risk of preterm birth by measuring serum metabolites. We hypothesised that serial metabolic modelling of serum analytes throughout pregnancy could be used to describe fetal gestational age and project preterm birth with a high degree of precision.

STUDY DESIGN

A retrospective cohort study.

SETTING

Two medical centres from the USA.

PARTICIPANTS

Thirty-six patients (20 full-term, 16 preterm) enrolled at Stanford University were used to develop gestational age and preterm birth risk algorithms, 22 patients (9 full-term, 13 preterm) enrolled at the University of Alabama were used to validate the algorithms.

OUTCOME MEASURES

Maternal blood was collected serially throughout pregnancy. Metabolic datasets were generated using mass spectrometry.

RESULTS

A model to determine gestational age was developed (R²=0.98) and validated (R²=0.81). 66.7% of the estimates fell within ±1 week of ultrasound results during model validation. Significant disruptions from full-term pregnancy metabolic patterns were observed in preterm pregnancies (R²=-0.68). A separate algorithm to predict preterm birth was developed using a set of 10 metabolic pathways that resulted in an area under the curve of 0.96 and 0.92, a sensitivity of 0.88 and 0.86, and a specificity of 0.96 and 0.92 during development and validation testing, respectively.

CONCLUSIONS

In this study, metabolic profiling was used to develop and test a model for determining gestational age during full-term pregnancy progression, and to determine risk of preterm birth. With additional patient validation studies, these algorithms may be used to identify at-risk pregnancies prompting alterations in clinical care, and to gain biological insights into the pathophysiology of preterm birth. Metabolic pathway-based pregnancy modelling is a novel modality for investigation and clinical application development.

Method to evaluate intravenous maintenance tocolysis for preterm labor

AIM

Despite the lack of evidence-based medicine, continuous intravenous maintenance tocolysis is the main treatment for preterm labor (PTL) in Japan because it is considered to prolong the gestational period. This treatment needs to be evaluated in more detail, and we herein propose one method to assess maintenance tocolysis using the timing of delivery by PTL patients.

METHODS

PTL patients (n = 307) were divided into three groups according to delivery weeks of gestation. Group A (severe PTL) delivered at <34 weeks, group B (mild PTL) at 34-37 weeks and group C (cases suspected overtreatment) at ≥38 weeks. The percentages of patients in each group was calculated and clinical characteristics were compared between groups.

RESULTS

The percentages of patients (%) in groups A, B and C were 33.9, 43.6 and 22.5, respectively. Gestational weeks on admission, maternal white blood cell count and C-reactive protein, PTL index, fetal fibronectin levels in vaginal secretions, amniotic fluid interleukin-8 levels, staying at neonatal intensive care unit were significantly different between these three groups by analysis of variance. Furthermore, amniotic fluid interleukin-8 levels were significantly higher in group B (3.5 [0.1-46.5] ng/mL) than in group C (1.7 [0.1-16.1], P < 0.05).

CONCLUSIONS

PTL patients were classified according to the prognosis. The ratio of patients in each group represented the severity of PTL and the risk of overtreatment. When this ratio is investigated on a nationwide scale, the use of intravenous maintenance tocolysis or definition of PTL may need to be reconsidered.

Current Preterm Birth Prevention Strategies

Preterm birth remains a major issue in obstetrics. Despite efforts to reduce the incidence of preterm delivery, rates in the United States remain high at 10.2% of all live births with an incidence of 10.8% globally. Preterm birth is the leading cause of neonatal morbidity and mortality worldwide. It is also the leading cause of death in children younger than 5 years. Research into this important health topic has allowed for the identification of risk factors for preterm birth, the most important of which is a history of prior preterm birth. Cervical length screening may allow us to identify those at greatest risk of recurrent preterm birth as well as a de novo risk in women with no prior preterm birth history.