Super-Utilizers of Inpatient Care in an Obstetrical Population: A Cross-Sectional Study

OBJECTIVE

 The aim of the study is to estimate hospital charges (HC) and length of stay (LOS) for pregnancy and 6 weeks postpartum and to characterize the outliers who utilize a disproportionate share of health care resources.

STUDY DESIGN

 We performed a cross-sectional study of 500 subjects at a tertiary center between 2012 and 2014. Subjects were included who had inpatient status and an ICD-9 code for pregnancy; those with an ICD-9 code for ectopic pregnancy were excluded. Data were collected 266 days prior to the estimated date of delivery (EDD) and up to 42 days post-delivery. Medical diagnoses, obstetrical details, demographics, HC, and LOS were collected. Super-utilizers (SUs) were selected as patients with total HC exceeding $75,000, those who incurred $75,000 or less were assigned to the typical utilizer (TU) group.

RESULTS

 HC was positively skewed, with median's (interquartile range) of $151,143 (97,707-198,732) and $28,186 (19,292-38,943) among SUs and TUs, respectively. Despite the low proportion of SU patients (7%, n = 36), they accounted for 30% of charges. Similarly, SUs had longer LOS (16 vs. 3 days, p <0.05). They had earlier deliveries (34.5 vs. 38.5 weeks, p <0.05), higher cesarean section rates (69 vs. 35%, p <0.05), and more hysterectomies (8.3 vs. 0%, p <0.05). The most common complications in SUs were preterm labor (33.3 vs. 5.4%, p <0.05) and preterm premature rupture of membranes (25 vs. 3.9%, p< 0.05). The most common pre-existing condition in SUs was chronic hypertension (11.1 vs. 3%, p< 0.05).

CONCLUSION

 Although SUs comprise only 7% of the obstetrical population, they account for almost a third of the total HCs; in turn, SUs are at risk of adverse outcomes. Targeting this population can guide efforts to improve maternal health through prevention, research, and personalized care. SUs may have clustering at hospitals with higher levels of care and this topic warrants further investigation with state and national level data.

KEY POINTS

· Just 7% of pregnant patients accounted for 30% of hospital charges.. · Super-utilizers had higher rates of preterm delivery, cesarean section, and hysterectomy.. · The most common pre-existing medical condition in super-utilizers was chronic hypertension..

Placental Abruption and Cardiovascular Event Risk (PACER): Design, data linkage, and preliminary findings

BACKGROUND

Obstetrical complications impact the health of mothers and offspring along the life course, resulting in an increased burden of chronic diseases. One specific complication is abruption, a life-threatening condition with consequences for cardiovascular health that remains poorly studied.

OBJECTIVES

To describe the design and data linkage algorithms for the Placental Abruption and Cardiovascular Event Risk (PACER) cohort.

POPULATION

All subjects who delivered in New Jersey, USA, between 1993 and 2020.

DESIGN

Retrospective, population-based, birth cohort study.

METHODS

We linked the vital records data of foetal deaths and live births to delivery and all subsequent hospitalisations along the life course for birthing persons and newborns. The linkage was based on a probabilistic record-matching algorithm.

PRELIMINARY RESULTS

Over the 28 years of follow-up, we identified 1,877,824 birthing persons with 3,093,241 deliveries (1.1%, n = 33,058 abruption prevalence). The linkage rates for live births-hospitalisations and foetal deaths-hospitalisations were 92.4% (n = 2,842,012) and 70.7% (n = 13,796), respectively, for the maternal cohort. The corresponding linkage rate for the live births-hospitalisations for the offspring cohort was 70.3% (n = 2,160,736). The median (interquartile range) follow-up for the maternal and offspring cohorts was 15.4 (8.1, 22.4) and 14.4 (7.4, 21.0) years, respectively. We will undertake multiple imputations for missing data and develop inverse probability weights to account for selection bias owing to unlinked records.

CONCLUSIONS

Pregnancy offers a unique window to study chronic diseases along the life course and efforts to identify the aetiology of abruption may provide important insights into the causes of future CVD. This project presents an unprecedented opportunity to understand how abruption may predispose women and their offspring to develop CVD complications and chronic conditions later in life.

Maternal Smoking and Risk of Hypertensive Disorders of Pregnancy: Effect Modification by Body Mass Index and Gestational Weight Gain

BACKGROUND

Although smoking cigarettes has been shown to have a protective effect on preeclampsia, quitting smoking also results in weight gain. Weight gain leading to an obese body mass index is a risk factor for hypertensive disorders of pregnancy (HDP).

METHODS

The objective of this study was to explore the relationship between smoking status, body mass index, and gestational weight gain on the risk of HDP. A cross-sectional analysis was performed utilizing US birth certificate data. We examined HDP risks in relation to maternal smoking, body mass index, and gestational weight gain. Associations were expressed as rate ratios with 95% CIs and adjusted for potential confounders. Clinically important outcomes of smoking throughout pregnancy were also evaluated.

RESULTS

Of the 22 191 568 women studied, HDP rates among nonsmokers, those who quit smoking, and persistent smokers were 6.8%, 8.6%, and 7.0%, respectively. The rate ratio of HDP was higher for women who quit smoking, especially evident among those with excessive gestational weight gain. Corrections for exposure misclassification and unmeasured confounding strengthened the associations among women who quit smoking. There was an almost 6-fold increase in the rate of stillbirth for persistent smokers (2.3%) compared with those who quit smoking (0.4%) and nonsmokers (0.4%).

CONCLUSIONS

Women who quit smoking during pregnancy were more likely to gain excessive weight and develop HDP. Although quitting smoking during pregnancy may be associated with an increase in the risk of HDP, it is also associated with a reduced risk of stillbirth. Pregnant women counseled to quit smoking should also receive counseling on nutrition and exercise to prevent excessive gestational weight gain.

Metformin Plus Insulin for Preexisting Diabetes or Gestational Diabetes in Early Pregnancy: The MOMPOD Randomized Clinical Trial

Importance

Insulin is recommended for pregnant persons with preexisting type 2 diabetes or diabetes diagnosed early in pregnancy. The addition of metformin to insulin may improve neonatal outcomes.

Objective

To estimate the effect of metformin added to insulin for preexisting type 2 or diabetes diagnosed early in pregnancy on a composite adverse neonatal outcome.

Design, Setting, and Participants

This randomized clinical trial in 17 US centers enrolled pregnant adults aged 18 to 45 years with preexisting type 2 diabetes or diabetes diagnosed prior to 23 weeks' gestation between April 2019 and November 2021. Each participant was treated with insulin and was assigned to add either metformin or placebo. Follow-up was completed in May 2022.

Intervention

Metformin 1000 mg or placebo orally twice per day from enrollment (11 weeks -<23 weeks) through delivery.

Main Outcome and Measures

The primary outcome was a composite of neonatal complications including perinatal death, preterm birth, large or small for gestational age, and hyperbilirubinemia requiring phototherapy. Prespecified secondary outcomes included maternal hypoglycemia and neonatal fat mass at birth, and prespecified subgroup analyses by maternal body mass index less than 30 vs 30 or greater and those with preexisting vs diabetes early in pregnancy.

Results

Of the 831 participants randomized, 794 took at least 1 dose of the study agent and were included in the primary analysis (397 in the placebo group and 397 in the metformin group). Participants' mean (SD) age was 32.9 (5.6) years; 234 (29%) were Black, and 412 (52%) were Hispanic. The composite adverse neonatal outcome occurred in 280 (71%) of the metformin group and in 292 (74%) of the placebo group (adjusted odds ratio, 0.86 [95% CI 0.63-1.19]). The most commonly occurring events in the primary outcome in both groups were preterm birth, neonatal hypoglycemia, and delivery of a large-for-gestational-age infant. The study was halted at 75% accrual for futility in detecting a significant difference in the primary outcome. Prespecified secondary outcomes and subgroup analyses were similar between groups. Of individual components of the composite adverse neonatal outcome, metformin-exposed neonates had lower odds to be large for gestational age (adjusted odds ratio, 0.63 [95% CI, 0.46-0.86]) when compared with the placebo group.

Conclusions and Relevance

Using metformin plus insulin to treat preexisting type 2 or gestational diabetes diagnosed early in pregnancy did not reduce a composite neonatal adverse outcome. The effect of reduction in odds of a large-for-gestational-age infant observed after adding metformin to insulin warrants further investigation.

Trial Registration

ClinicalTrials.gov Identifier: NCT02932475.

Perinatal Outcomes Associated With Management of Stage 1 Hypertension

OBJECTIVE

To evaluate the association between maternal blood pressure (BP) below 130/80 mm Hg compared with 130-139/80-89 mm Hg and pregnancy outcomes.

METHODS

We conducted a planned secondary analysis of CHAP (Chronic Hypertension and Pregnancy), an open label, multicenter, randomized controlled trial. Participants with mean BP below 140/90 mm Hg were grouped as below 130/80 mm Hg compared with 130-139/80-89 mm Hg by averaging postrandomization clinic BP throughout pregnancy. The primary composite outcome was preeclampsia with severe features, indicated preterm birth before 35 weeks of gestation, placental abruption, or fetal or neonatal death. The secondary outcome was small for gestational age (SGA).

RESULTS

Of 2,408 patients in CHAP, 2,096 met study criteria; 1,328 had mean BP 130-139/80-89 mm Hg and 768 had mean BP below 130/80 mm Hg. Participants with mean BP below 130/80 mm Hg were more likely to be older, on antihypertensive medication, in the active treatment arm, and to have lower BP at enrollment. Mean clinic BP below 130/80 mm Hg was associated with lower frequency of the primary outcome (16.0% vs 35.8%, adjusted relative risk 0.45; 95% CI 0.38-0.54) as well as lower risk of severe preeclampsia and indicated birth before 35 weeks of gestation. There was no association with SGA.

CONCLUSION

In pregnant patients with mild chronic hypertension, mean BP below 130/80 mm Hg was associated with improved pregnancy outcomes without increased risk of SGA.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov , NCT02299414.

Cesarean scar ectopic pregnancy: nuances in diagnosis and treatment

A cesarean scar ectopic pregnancy (CSEP) occurs when the embryo implants on the scar of a previous cesarean delivery. The number of births delivered by cesarean section has climbed by 50% over the last decade, from a nadir of 20.7% in 1996 to 32.1% in 2021. As a result, the incidence of CSEP has also increased. Because CSEP may cause serious morbidity such as life-threatening hemorrhage, uterine rupture, placental accreta spectrum, hysterectomy, and even mortality, accurate diagnosis and appropriate management of this condition are essential. This review focuses on the etiology, incidence, clinical diagnosis, and management of CSEPs.

Breastfeeding initiation and duration among people with mild chronic hypertension: a secondary analysis of the Chronic Hypertension and Pregnancy trial

BACKGROUND

Increased duration of breastfeeding improves maternal cardiovascular health and may be especially beneficial in high-risk populations, such as those with chronic hypertension. Others have shown that individuals with hypertension are less likely to breastfeed, and there has been limited research aimed at supporting breastfeeding goals in this population. The impact of perinatal blood pressure control on breastfeeding outcomes among people with chronic hypertension is unknown.

OBJECTIVE

This study aimed to evaluate whether breastfeeding initiation and short-term duration assessed at the postpartum clinic visit differed according to perinatal blood pressure treatment strategy (targeting blood pressure <140/90 mm Hg vs reserving antihypertensive treatment for blood pressure ≥160/105 mm Hg).

STUDY DESIGN

We performed a secondary analysis of the Chronic Hypertension and Pregnancy trial. This was an open-label, multicenter, randomized trial where pregnant participants with mild chronic hypertension were randomized to receive antihypertensive medications with goal blood pressure <140/90 mm Hg (active treatment) or deferred treatment until blood pressure ≥160/105 mm Hg (control). The primary outcome was initiation and duration of breastfeeding, assessed at the postpartum clinic visit. We performed bivariate analyses and log-binomial and cumulative logit regression models, adjusting models for variables that were unbalanced in bivariate analyses. We performed additional analyses to explore the relationship between breastfeeding duration and blood pressure measurements at the postpartum visit.

RESULTS

Of the 2408 participants from the Chronic Hypertension and Pregnancy trial, 1444 (60%) attended the postpartum study visit and provided breastfeeding information. Participants in the active treatment group had different body mass index class distribution and earlier gestational age at enrollment, and (by design) were more often discharged on antihypertensives. Breastfeeding outcomes did not differ significantly by treatment group. In the active and control treatment groups, 563 (77.5%) and 561 (78.1%) initiated breastfeeding, and mean durations of breastfeeding were 6.5±2.3 and 6.3±2.1 weeks, respectively. The probability of ever breastfeeding (adjusted relative risk, 0.99; 95% confidence interval, 0.93-1.05), current breastfeeding at postpartum visit (adjusted relative risk, 1.01; 95% confidence interval, 0.94-1.10), and weeks of breastfeeding (adjusted odds ratio, 0.87; 95% confidence interval, 0.68-1.12) did not differ by treatment group. Increased duration (≥2 vs <2 weeks) of breastfeeding was associated with slightly lower blood pressure measurements at the postpartum visit, but these differences were not significant in adjusted models.

CONCLUSION

In a secondary analysis of the cohort of Chronic Hypertension and Pregnancy trial participants who attended the postpartum study visit and provided breastfeeding information (60% of original trial participants), breastfeeding outcomes did not differ significantly by treatment group. This suggests that maintaining goal blood pressure <140/90 mm Hg throughout the perinatal period is associated with neither harm nor benefit for short-term breastfeeding goals. Further study is needed to understand long-term breastfeeding outcomes among individuals with chronic hypertension and how to support this population in achieving their breastfeeding goals.

Treatment for Mild Chronic Hypertension during Pregnancy

BACKGROUND

The benefits and safety of the treatment of mild chronic hypertension (blood pressure, <160/100 mm Hg) during pregnancy are uncertain. Data are needed on whether a strategy of targeting a blood pressure of less than 140/90 mm Hg reduces the incidence of adverse pregnancy outcomes without compromising fetal growth.

METHODS

In this open-label, multicenter, randomized trial, we assigned pregnant women with mild chronic hypertension and singleton fetuses at a gestational age of less than 23 weeks to receive antihypertensive medications recommended for use in pregnancy (active-treatment group) or to receive no such treatment unless severe hypertension (systolic pressure, ≥160 mm Hg; or diastolic pressure, ≥105 mm Hg) developed (control group). The primary outcome was a composite of preeclampsia with severe features, medically indicated preterm birth at less than 35 weeks' gestation, placental abruption, or fetal or neonatal death. The safety outcome was small-for-gestational-age birth weight below the 10th percentile for gestational age. Secondary outcomes included composites of serious neonatal or maternal complications, preeclampsia, and preterm birth.

RESULTS

A total of 2408 women were enrolled in the trial. The incidence of a primary-outcome event was lower in the active-treatment group than in the control group (30.2% vs. 37.0%), for an adjusted risk ratio of 0.82 (95% confidence interval [CI], 0.74 to 0.92; P<0.001). The percentage of small-for-gestational-age birth weights below the 10th percentile was 11.2% in the active-treatment group and 10.4% in the control group (adjusted risk ratio, 1.04; 95% CI, 0.82 to 1.31; P = 0.76). The incidence of serious maternal complications was 2.1% and 2.8%, respectively (risk ratio, 0.75; 95% CI, 0.45 to 1.26), and the incidence of severe neonatal complications was 2.0% and 2.6% (risk ratio, 0.77; 95% CI, 0.45 to 1.30). The incidence of any preeclampsia in the two groups was 24.4% and 31.1%, respectively (risk ratio, 0.79; 95% CI, 0.69 to 0.89), and the incidence of preterm birth was 27.5% and 31.4% (risk ratio, 0.87; 95% CI, 0.77 to 0.99).

CONCLUSIONS

In pregnant women with mild chronic hypertension, a strategy of targeting a blood pressure of less than 140/90 mm Hg was associated with better pregnancy outcomes than a strategy of reserving treatment only for severe hypertension, with no increase in the risk of small-for-gestational-age birth weight. (Funded by the National Heart, Lung, and Blood Institute; CHAP ClinicalTrials.gov number, NCT02299414.).

Evaluation of classic and novel ultrasound signs of placenta accreta spectrum

OBJECTIVES

Improvement in the antenatal diagnosis of placenta accreta spectrum (PAS) would allow preparation for delivery in a referral center, leading to decreased maternal morbidity and mortality. Our objectives were to assess the performance of classic ultrasound signs and to determine the value of novel ultrasound signs in the detection of PAS.

METHODS

This was a retrospective cohort study of women with second-trimester placenta previa who underwent third-trimester transvaginal ultrasound and all women with PAS in seven medical centers. A retrospective image review for signs of PAS was conducted by three maternal-fetal medicine physicians. Classic signs of PAS were defined as placental lacunae, bladder-wall interruption, myometrial thinning and subplacental hypervascularity. Novel signs were defined as small placental lacunae, irregular placenta-myometrium interface (PMI), vascular PMI, non-tapered placental edge and placental bulge towards the bladder. PAS was diagnosed based on difficulty in removing the placenta or pathological examination of the placenta. Multivariate regression analysis was performed and receiver-operating-characteristics (ROC) curves were generated to assess the performance of combined novel signs, combined classic signs and a model combining classic and novel signs.

RESULTS

A total of 385 cases with placenta previa were included, of which 55 had PAS (28 had placenta accreta, 11 had placenta increta and 16 had placenta percreta). The areas under the ROC curves for classic markers, novel markers and a model combining classic and novel markers for the detection of PAS were 0.81 (95% CI, 0.75-0.88), 0.84 (95% CI, 0.77-0.90) and 0.88 (95% CI, 0.82-0.94), respectively. A model combining classic and novel signs performed better than did the classic or novel markers individually (P = 0.03). An increasing number of signs was associated with a greater likelihood of PAS. With the presence of 0, 1, 2 and ≥ 3 classic ultrasound signs, PAS was present in 5%, 24%, 57% and 94% of cases, respectively.

CONCLUSIONS

We have confirmed the value of classic ultrasound signs of PAS. The use of novel ultrasound signs in combination with classic signs improved the detection of PAS. These findings have clinical implications for the detection of PAS and may help guide the obstetric management of patients diagnosed with these placental disorders. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Obstetrical outcomes and follow-up for patients with asymptomatic COVID-19 at delivery: a multicenter prospective cohort study

BACKGROUND

Universal testing for COVID-19 on admission to the labor and delivery unit identifies asymptomatic patients. Whether or not these patients are at increased risk for adverse outcomes and go on to develop clinically significant disease is uncertain.

OBJECTIVE

This study aimed to assess the prevalence of asymptomatic COVID-19 presentation among pregnant patients admitted for delivery and to determine whether these patients become symptomatic or require hospital readmission after discharge.

STUDY DESIGN

We performed a multicenter, prospective cohort study of pregnant patients who delivered between 20^0/7 and 41^6/7 weeks’ gestation and who were found to have COVID-19 based on universal screening on admission for delivery at 1 of 4 medical centers in New Jersey (exposed group). The unexposed group, comprising patients who tested negative for COVID-19, were identified at the primary study site. The primary outcomes were the rates of asymptomatic COVID-19 presentation, the development of symptoms among the asymptomatic positive patients, and hospital readmission rates in the 2 weeks following discharge. We compared the frequency of the distribution of risk factors and outcomes in relation to the COVID-19 status among patients with COVID-19 across all centers and among those without COVID-19 at the primary site. Associations between categorical risk factors and COVID-19 status were expressed as relative risks with 95% confidence intervals.

RESULTS

Between April 10, 2020, and June 15, 2020, there were 218 patients with COVID-19 at the 4 sites and 413 patients without COVID-19 at the primary site. The majority (188 [83.2%]) of patients with COVID-19 were asymptomatic. Compared with the negative controls, these asymptomatic patients were not at increased risk for obstetrical complications that may increase the risk associated with COVID-19, including gestational diabetes (8.2% vs 11.4%; risk ratio, 0.72; 95% confidence interval, 0.24–2.01) and gestational hypertension (6.1% vs 7.0%; risk ratio, 0.88; 95% confidence interval, 0.29–2.67). Postpartum follow-ups via telephone surveys revealed that these patients remained asymptomatic and had low rates of family contacts acquiring the disease, but their adherence to social distancing guidelines waned during the 2-week postpartum period. Review of inpatient and emergency department records revealed low rates of hospital readmission.

CONCLUSION

Most of the pregnant patients who screened positive for COVID-19 are asymptomatic and do not go on to develop clinically significant infection after delivery. Routine surveillance of these patients after hospital discharge appears to be sufficient.

miR-15b-5p promotes expression of proinflammatory cytokines in human placenta by inhibiting Apelin signaling pathway

INTRODUCTION

The timing of parturition at end of human gestation may be controlled by fetal signals. The signaling molecules contributing to activation of human labor may be mediated by fetal exosomes. In this study, we focused on investigation of the role of microRNAs (miRNAs) derived from fetal exosomes in the regulation of human placental gene expression.

METHODS

Using immunofluorescent labeling, array-based miRNA profiling assay, target prediction analysis, and conducting a variety of biochemical approaches including miRNA mimics, dual-luciferase, siRNA-mediated gene silencing, and immunohistochemical staining assay in primary trophoblast culture and formalin-fixed paraffin-embedded placental tissues, we examined whether fetal exosomal miRNAs can stimulate expression of proinflammatory mediators in human placenta.

RESULTS

We showed placental uptake of exosomes derived from the umbilical artery, and found that 9 fetal exosomal miRNAs: let-7i-5p, miR-185-5p, miR-15b-5p, miR-376c-3p, miR-548d-5p, miR-92b-3p, miR-16-5p, and miR-1301-3p were significantly increased in placentas of women delivering following term labor compared to those delivering by Cesarean section in the late preterm period. Target prediction analysis identified miR-15b-5p of particular interest, because one of its predicted targets is Apelin, a potent inhibitor of proinflammatory mediators. We further found that miR-15b-5p repressed Apelin protein levels and activated pro-labor hormones and cytokines including IL-1, IL-6, IL-8, and TNF-α.

DISCUSSION

These data suggest a potential fetal-to-placental signal that could play a role in the length of human gestation and onset of human labor.

A comparison of pregnancy-specific risk scoring systems for venous thromboembolic pharmacoprophylaxis in hospitalized maternity patients

OBJECTIVE

Venous thromboembolism (VTE) remains a leading cause of maternal mortality. The American College of Obstetricians and Gynecologists (ACOG) and the Royal College of Obstetricians & Gynecologists (RCOG) have proposed pregnancy-specific risk scoring guidelines for antepartum (AP) and postpartum (PP) thromboprophylaxis. We compared the impact of scoring thresholds and their potential preventative effect.

STUDY DESIGN

We conducted a retrospective cohort study of hospitalized maternity patients over a 4-month period. Patients were assigned an AP and PP risk score using each guideline. Hospitalization-associated VTE was accessed over a 6-year period. Comparison was by Fischer's exact and Chi Square tests.

RESULTS

638 women were included. Of AP patients, 20% met pharmacoprophylaxis criteria for baseline characteristics and 100% for length of stay using RCOG, and 12% met phrarmacoprophylaxis criteria using ACOG (p < .001). For PP patients, 53% met criteria for RCOG compared to 24% using ACOG (p < .001). If pharmacoprophylaxis were performed at a threshold 1 point above recommendation, 7% of AP patients and 11% of PP women would meet ACOG criteria. This increased ACOG threshold captured all cases of VTE following hospitalization.

CONCLUSION

In our population, using ACOG prophylaxis guidelines at an increased threshold would have potentially prevented all hospitalization related VTE without excessive anti-coagulation.

Pharmacologic intervention for the management of retained placenta: a systematic review and meta-analysis of randomized trials

BACKGROUND

Retained placenta affects 2% to 3.3% of all vaginal deliveries and is one of the leading causes of postpartum hemorrhage worldwide. Despite the prevalence of this condition, there is limited guidance on its management.

OBJECTIVE

A systematic review and meta-analysis were performed to evaluate the efficacy of pharmacologic interventions for the management of retained placenta.

STUDY DESIGN

PubMed, ClinicalTrials.gov, Cochrane Library, Web of Science, and Scopus were searched for full-text publications in English. Search terms included "retained placenta" AND "treatment" OR "therapy" OR "disease management" OR "Pitocin" OR "misoprostol" OR "Cytotec" OR "dinoprostone" OR "nitroglycerin" OR "carbetocin" OR "ergotamine," with no restriction on publication dates. Only randomized controlled trials were included. The primary outcome was the need for manual extraction of the placenta or dilation and curettage. Reviewers evaluated the quality of included articles using the Cochrane Collaboration's tool for assessing the risk of bias. Pooled risk ratios were estimated based on random- and fixed-effects analyses. Interstudy heterogeneity was considered when I²≥50%.

RESULTS

The literature search identified 29 randomized controlled trials that met the inclusion criteria (2682 subjects). The most commonly used agent across the studies was oxytocin administered via umbilical vein injection; there was high heterogeneity among these studies (I²=62%). Oxytocin was inferior to carbetocin (risk ratio, 1.61; 95% confidence interval, 1.03-2.52) and prostaglandins (risk ratio, 2.63; 95% confidence interval, 1.18-5.86) for the primary outcome. For oxytocin, prostaglandin agents, and nitroglycerin, there was a trend toward favoring the study drug for the primary outcome compared with control or placebo. Compared with placebo or control, estimated blood loss was lower if pharmacologic interventions were administered, with a mean difference of 121.5 mL (95% confidence interval, -185.7 to -52.3). There was no difference in postpartum hemorrhage or the need for blood transfusion between pharmacologic interventions and placebo or control.

CONCLUSION

Pooled estimates for oxytocin via umbilical vein injection, prostaglandin agents, and nitroglycerin performed favorably compared with placebo or control for the management of retained placenta. Carbetocin and prostaglandin agents were superior to oxytocin in reducing the need for manual extraction or dilation and curettage.

Fetal Exosomal Platelet-activating Factor Triggers Functional Progesterone Withdrawal in Human Placenta

In most mammals, labor is heralded by the withdrawal of progesterone. In humans, circulating progesterone levels increase as gestation advances while placental expression of progesterone receptor A (PR-A) declines. As a result of PR-A downregulation, the non-canonical NF-κB pathway is activated, an event implicated in triggering labor. Here, we sought to identify fetal-derived mediator(s) that represses placental PR-A in human placenta leading to activation of pro-labor signaling. Lipidomic profiling demonstrated enrichment of platelet-activating factor (PAF) in exosomes originating from the human fetus. Exposure of primary cytotrophoblasts to fetal exosomes from term pregnancies reduced PR-A expression by > 50%, and PAF also reduced PR-A message levels in a dose-dependent manner. Notably, fetal exosomes from preterm pregnancies had lower PAF levels and no effect on PR-A expression. Synthetic PAF-induced DNA methylation increases by 20% at the PR-A promoter, leading to recruitment of corepressors and downregulation of PR-A in cytotrophoblast. Furthermore, suppression of PR-A by PAF-stimulated expression of the pro-labor genes, corticotropin-releasing hormone (CRH) and cyclooxygenase-2 (COX-2), which was reversed by disruption of the DNA methyltransferases 3B and 3L. Taken together, PAF represents a novel fetal-derived candidate for initiation of labor by stimulating methylation and repression of PR-A and activating pro-labor signaling in trophoblast.

Assessing resilience of healthcare infrastructure exposed to COVID-19: emerging risks, resilience indicators, interdependencies and international standards

In the moment of preparation of this paper, the world is still globally in grip of the Corona (COVID-19) crisis, and the need to understand the broader overall framework of the crisis increases. As in similar cases in the past, also with this one, the main interest is on the “first response”. Fully appreciating the efforts of those risking their lives facing pandemics, this paper tries to identify the main elements of the larger, possibly global, framework, supported by international standards, needed to deal with new (emerging) risks resulting from threats like Corona and assess the resilience of systems affected. The paper proposes that future solutions should include a number of new elements, related to both risk and resilience. That should include broadening the scope of attention, currently focused onto preparation and response phases, to the phases of “understanding risks”, including emerging risks, and transformation and adaptation. The paper suggests to use resilience indicators in this process. The proposed approach has been applied in different cases involving critical infrastructures in Europe (energy supply, water supply, transportation, etc., exposed to various threats), including the health system in Austria. The detailed, indicator-based, resilience analysis included mapping resilience, resilience stress-testing, visualization, etc., showing, already before the COVID-19, the resilience (stress-testing) limits of the infrastructures. A simpler (57 indicator based) analysis has, then been done for 11 countries (including Austria). The paper links these results with the options available in the area of policies, standards, guidelines and tools (such as the RiskRadar), with focus on interdependencies and global standards—especially the new ISO 31,050, linking emerging risks and resilience.

Characterization of Perineum Elasticity and Pubic Bone-Perineal Critical Distance with a Novel Tactile Probe: Results of an Intraobserver Reproducibility Study

BACKGROUND

Tactile imaging provides biomechanical mapping of soft tissues. Objective biomechanical and anatomical assessment of critical structures within the vagina and pelvis may allow development and validation of a clinical tool that could assist with clinical decisions regarding obstetrical procedures and mode of delivery. Objective: To assess intraobserver reproducibility of measurements of perineal elasticity and pubic bone-perineal critical distance with a novel tactile probe in pregnant women.

METHODS

An Antepartum Tactile Imager (ATI) was designed with a vaginal probe resembling a fetal skull. The probe comprises 128 tactile sensors on a double curved surface and measures 46 mm in width and 72 mm in length. The probe has a motion tracking sensor that allows acquisition of 3D tactile images. There were two arms of the study. In the first arm, biomechanical mapping of the perineum and pelvic bone location was performed in 10 non-pregnant women for purposes of demonstrating safety and feasibility. In the second arm, biomechanical mapping was performed in 10 pregnant women to explore intraobserver reproducibility. Each subject had two standardized examinations over 3 - 5 minutes by the same observer. Examination comfort and pain levels were assessed by post-procedure survey. Reproducibility was analyzed by intraclass correlation coefficients (ICC) with 95% confidence intervals and Bland-Altman plots. Bias and the 95% limits of agreement were also calculated.

RESULTS

The safety and feasibility arm of the study demonstrated high degree of safety and tolerability and reliable acquisition of tactile signals. In the reproducibility arm, 10 pregnant women were recruited at mean gestational age of 34.2 ± 6.5 weeks. The mean perineum elasticity (Young's modulus, E) was 9.8 ± 5.9 kPa, and the mean pubic bone-perineal critical distance (D) at 20 kPa load was 34.6 ± 6.2 mm. The ICC was 0.97 [95% confidence interval (CI) 0.91, 0.99] and 0.82 [CI 0.44, 0.95] for E and D respectively, consistent with excellent intrarater agreement. The bias and the 95% limits of agreement of E were -6.3% and -29.4% to +16.7%, respectively. The bias and the 95% limits of agreement of D were -2.6% and -25.3% to +20.2%, respectively.

CONCLUSIONS

The tactile imaging data obtained in the study reproducibly characterized perineal elasticity and pubic bone-perineal critical distance. Further evaluation of this tool in clinical settings is warranted.

Cervical Characterization with Tactile-Ultrasound Probe

BACKGROUND

Premature cervical softening and shortening may be considered an early mechanical failure that predisposes to preterm birth. Preliminary clinical studies demonstrate that cervical elastography may be able to quantify this phenomenon and predict spontaneous preterm delivery.

OBJECTIVE

To explore a new approach for cervix elasticity and length measurements with tactile-ultrasound probe.

METHODS

Cervix probe has tactile array and ultrasound transducer designed to apply controllable load to cervix and acquire stress-strain data for calculation of cervical elasticity (Young's modulus) and cervical length for four cervix sectors. Average values, standard deviations, intraclass correlation coefficients and the 95% limits of agreement (Bland-Altman plots) were estimated.

RESULTS

Ten non-pregnant and ten pregnant women were examined with the probe. The study with non-pregnant women demonstrated a reliable acquisition of the tactile signals. The ultrasound signals had a prolonged appearance; identification of the internal os of the cervix in these signals was not reliable. The study with pregnant women with the gestational age of 25.4 ± 2.3 weeks demonstrated reliable data acquisition with real-time visualization of the ultrasound signals. Average values for cervical elasticity and standard deviations of 19.7 ± 15.4 kPa and length of 30.7 ± 6.6 mm were calculated based on two measurements per 4 sectors. Measurement repeatability calculated as intraclass correlation coefficients between two measurements at the same cervix sector on pregnant women was found to be 0.97 for cervical elasticity and 0.93 for the cervical length. The 95% limits of agreement of 1) cervical elasticity were from -22.4% to +14.9%, and 2) cervical length from -13.3% to +16.5%.

CONCLUSIONS

This study demonstrated clinically acceptable measurement performance and reproducibility. The availability of stress-strain data allowed the computation of cervical elasticity and length. This approach has the potential to provide cervical markers to predict spontaneous preterm delivery.

A Bibliometric Analysis of Top-Cited Journal Articles in Obstetrics and Gynecology

IMPORTANCE

Citation analysis is a bibliometric method that uses citation rates to evaluate research performance. This type of analysis can identify the articles that have shaped the modern history of obstetrics and gynecology (OBGYN).

OBJECTIVES

To identify and characterize top-cited OBGYN articles in the Institute for Scientific Information Web of Science's Science Citation Index Expanded and to compare top-cited OBGYN articles published in specialty OBGYN journals with those published in nonspecialty journals.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional bibliometric analysis of top-cited articles that were indexed in the Science Citation Index Expanded from 1980 to 2018. The Science Citation Index Expanded was queried using search terms from the American Board of Obstetrics and Gynecology's 2018 certifying examination topics list. The top 100 articles from all journals and the top 100 articles from OBGYN journals were evaluated for specific characteristics. Data were analyzed in March 2019.

MAIN OUTCOMES AND MEASURES

The articles were characterized by citation number, publication year, topic, study design, and authorship. After excluding articles that featured on both lists, top-cited articles were compared.

RESULTS

The query identified 3 767 874 articles, of which 278 846 (7.4%) were published in OBGYN journals. The top-cited article was published by Rossouw and colleagues in JAMA (2002). Top-cited articles published in nonspecialty journals were more frequently cited than those in OBGYN journals (median [interquartile range], 1738 [1490-2077] citations vs 666 [580-843] citations, respectively; P < .001) and were more likely to be randomized trials (25.0% vs 2.2%, respectively; difference, 22.8%; 95% CI, 13.5%-32.2%; P < .001). Whereas articles from nonspecialty journals focused on broad topics like osteoporosis, articles from OBGYN journal focused on topics like preeclampsia and endometriosis.

CONCLUSIONS AND RELEVANCE

This study found substantial differences between top-cited OBGYN articles published in nonspecialty vs OBGYN journals. These differences may reflect the different goals of the journals, which work together to ensure optimal dissemination of impactful articles.

Fetal lung C4BPA induces p100 processing in human placenta

The non-canonical NF-κB signaling may be a central integrator of a placental clock that governs the length of human pregnancy. We sought to identify fetal signals that could activate this NF-κB pathway in the placenta, and in turn, contribute to the onset of labor. Proteomics analysis of exosomes purified from fetal cord arterial blood revealed a total of 328 proteins, among which 48 were more significantly abundant (p < 0.01) in samples from women who delivered following elective Cesarean-section at term (39 to 40 weeks of estimated gestational age, EGA) compared to those who had elective Cesarean deliveries near term (35 to 36 weeks of EGA). Computational, crystal structural, and gene functional analyses showed that one of these 48 proteins, C4BPA, binds to CD40 of placental villous trophoblast to activate p100 processing to p52, and in turn, pro-labor genes. These results suggest that fetal C4BPA-induced activation of non-canonical NF-κB in human placenta may play a critical role in processes of term or preterm labor.

Integrated RNA-seq and ChIP-seq analysis reveals a feed-forward loop regulating H3K9ac and key labor drivers in human placenta

BACKGROUND

Chromatin alterations are important mediators of gene expression changes. We have recently shown that activated non-canonical NF-κB signaling (RelB/p52) recruits histone acetyltransferase CBP and deacetylase HDAC1 to selectively acetylate H3K9 (H3K9ac) to induce expression of corticotropin-releasing hormone (CRH) and prostaglandin-endoperoxide synthase-2 (PTGS2) in the human placenta. Both of these genes play a role in initiating parturition in human pregnancy.

METHODS

We performed chromatin immunoprecipitation followed by gene sequencing (ChIP-seq) in primary term human cytotrophoblast (CTB) with use of antibodies to RelB, CBP, HDAC1 and H3K9ac. We further associated these chromatin alterations with gene expression changes from mid-trimester to term in CTB by RNA sequencing (RNA-seq).

RESULTS

We detected a genome-wide differential gene enrichment between mid-trimester and term human placenta. Pathway analysis identified that cytokine-cytokine receptor interaction, NF-κB, and TNF are the leading pathways enriched in term placenta and associated with these chromatin alterations.

DISCUSSIONS

Our analysis has provided the first-time characterization of the key players of human placental origin with molecular changes resulting from chromatin modifications, which could drive human labor.

Anandamide down-regulates placental transporter expression through CB2 receptor-mediated inhibition of cAMP synthesis

The BCRP/ABCG2 efflux transporter is expressed on the membrane of placental syncytiotrophoblasts and protects the fetus from toxicant exposure. Syncytiotrophoblasts arise from the fusion of cytotrophoblasts, a process negatively regulated by the endocannabinoid, anandamide (AEA). It is unknown whether AEA can influence fetal concentrations of xenobiotics by modulating the expression of transporters in syncytiotrophoblasts. Here, we sought to characterize and identify the mechanism(s) responsible for AEA-mediated down-regulation of the BCRP transporter in human placental explants and BeWo trophoblasts. Treatment of human placental explants with AEA (1 μM, 24 h) reduced hCGα, syncytin-1, and BCRP mRNAs by ˜30%. Similarly, treatment of BeWo trophoblasts with AEA (0-10 μM, 3-24 h) coordinately down-regulated mRNAs for hCGß, syncytin-2, and BCRP. In turn, AEA increased the sensitivity of trophoblasts to the cytotoxicity of mitoxantrone, a known BCRP substrate, and environmental and dietary contaminants including mycoestrogens and perfluorinated chemicals. AEA-treated trophoblasts also demonstrated reduced BCRP transport of the mycoestrogen zearalenone and the diabetes drug glyburide, labeled with BODIPY. The AEA-mediated reduction of BCRP mRNA was abrogated when placental cells were co-treated with AM630, a CB2 receptor inhibitor, or 8-Br-cAMP, a cAMP analog. AEA reduced intracellular cAMP levels in trophoblasts by 75% at 1 h, and completely inhibited forskolin-induced phosphorylation of the cAMP response element binding protein (CREB). AEA also decreased p-CREB binding to the BCRP promoter. Taken together, our data indicate that AEA down-regulates placental transporter expression and activity via CB2-cAMP signaling. This novel mechanism may explain the repression of placental BCRP expression observed during diseases of pregnancy.

Vitamin D stimulates multiple microRNAs to inhibit CRH and other pro-labor genes in human placenta

Maternal vitamin D deficiency is linked to adverse pregnancy outcomes including spontaneous preterm birth (SPB). Placental corticotropin-releasing hormone (CRH) has been proposed to be part of a clock that governs the length of gestation in humans, with elevated maternal serum levels predicting early delivery. In this study, we test the hypothesis that vitamin D could contribute to the prevention of preterm labor by inhibiting CRH and other pro-labor mediators. The biological activity of vitamin D occurs via two pathways: non-genomic and genomic responses, both of which involve binding of 1,25-dihydroxyvitamin D (1,25(OH)2D), the active metabolite of vitamin D binding to the vitamin D receptor (VDR). By using chromatin immunoprecipitation followed by sequencing (ChIP-seq), we found that 1,25(OH)2D stimulates association of VDR with a number of miRNA genes including MIR181B2 and MIR26B, and their mature products miR-181b-5p and miR-26b-5p are predicted to target CRH and cyclooxygenase-2 (COX-2) mRNA at 3'-untranslated region (UTR), respectively. We performed RT-qPCR analysis to validate that expression of mature miR-181b-5p and miR-26b-5p in term human syncytiotrophoblast increased in response to treatment with 1,25(OH)2D. miR-181b-5p- or miR-26b-5p-mediated inhibition of CRH or COX-2 was further assessed by the use of miRNA mimics/inhibitors and a luciferase reporter assay. Taken together, this study has identified novel mechanisms by which vitamin D downregulates pro-labor genes and could lower the risk of preterm delivery.

Trends in invasive prenatal diagnostic testing at a single institution

OBJECTIVE

As diagnostic methodologies evolve, we sought to determine whether invasive testing rates would decline, whether there would be a shift in indications for invasive testing, and whether the diagnostic yield would increase.

METHODS

We conducted a retrospective, observational study from 2006 through 2015. We quantified the number of invasive procedures per year and examined what percentage of these procedures yielded abnormal results. We also examined the indications for testing and determined the trend of these indications during the study period.

RESULTS

The number of amniocenteses showed a steady decline (P < .05). The number of CVS procedures has increased and was recently equivalent to amniocentesis. The percentage of abnormal results steadily increased from 11.4% to 27.0% (P < .001). The abnormal aneuploidy screening indication remained constant over time. Advanced maternal age (AMA) as the sole indication substantially declined from 42.3% to 15.52% (P < .001). Testing for a known single gene disorder steadily increased from 3.0% to 9.20% (P = .018).

CONCLUSION

Our study showed a significant decline in the number of amniocenteses, a steady increase in the percentage of abnormal results from invasive testing, and a decline in AMA as the sole indication for invasive testing.

Screening a small molecule library to identify inhibitors of NF-κB inducing kinase and pro-labor genes in human placenta

The non-canonical NF-κB signaling (RelB/p52) pathway drives pro-labor genes in the human placenta, including corticotropin-releasing hormone (CRH) and cyclooxygenase-2 (COX-2), making this a potential therapeutic target to delay onset of labor. Here we sought to identify small molecule compounds from a pre-existing chemical library of orally active drugs that can inhibit this NF-κB signaling, and in turn, human placental CRH and COX-2 production. We used a cell-based assay coupled with a dual-luciferase reporter system to perform an in vitro screening of a small molecule library of 1,120 compounds for inhibition of the non-canonical NF-κB pathway. Cell toxicity studies and drug efflux transport MRP1 assays were used to further characterize the lead compounds. We have found that 14 drugs have selective inhibitory activity against lymphotoxin beta complex-induced activation of RelB/p52 in HEK293T cells, several of which also inhibited expression of CRH and COX-2 in human term trophoblast. We identified sulfapyridine and propranolol with activity against CRH and COX-2 that deserve further study. These drugs could serve as the basis for development of orally active drugs to affect length of gestation, first in an animal model, and then in clinical trials to prevent preterm birth during human pregnancy.

Cerclage in twin pregnancy with dilated cervix between 16 to 24 weeks of gestation: retrospective cohort study

BACKGROUND

Cervical dilation in the second trimester is associated with a greater than 90% rate of spontaneous preterm birth and a poor perinatal prognosis.

OBJECTIVE

To compare the perinatal outcomes of twin pregnancies with dilated cervix in women who underwent either cerclage or expectant management.

STUDY DESIGN

Retrospective cohort study of asymptomatic twin pregnancies identified with cervical dilation of ≥1 cm at 16-24 weeks (1997-2014) at 7 institutions. Exclusion criteria were genetic or major fetal anomaly, multifetal reduction at >14 weeks, prior cerclage placement, monochorionic-monoamniotic placentation, active vaginal bleeding, labor, chorioamnionitis, elective termination of pregnancy, or medically indicated preterm birth. The primary outcome was incidence of spontaneous preterm birth at <34 weeks. Secondary outcomes were incidence of spontaneous preterm birth at <32 weeks, <28 weeks, and <24 weeks; perinatal mortality; and composite adverse neonatal outcome (respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, and sepsis).

RESULTS

A total of 76 women with twin pregnancy with dilated cervix of 1.0-4.5 cm were managed with either cerclage (n = 38) or expectant management (n = 38). Demographic characteristics were not significantly different. Analysis was adjusted for amniocentesis and vaginal progesterone use. In the cerclage group, 29 women (76%) received prophylactic indomethacin and 36 (94%) received prophylactic antibiotics, whereas the expectant management group did not. Interval from time at diagnosis of open cervix to delivery in the cerclage group was 10.46 ± 5.6 weeks vs 3.7 ± 3.2 weeks in the expectant management group, with a mean difference of 6.76 weeks (95% confidence interval [CI], 4.71-8.81). There were significant decreases in spontaneous preterm birth at <34 weeks (52.6% vs 94.7%; adjusted odds ratio [aOR], 0.06; 95% CI, 0.03-0.34), at <32 weeks (44.7% vs 89.4%; aOR, 0.08; 95% CI, 0.03-0.34); at <28 weeks (31.6% vs 89.4%; aOR, 0.05; 95% CI, 0.01-0.2); and at <24 weeks (13.1% vs 47.3%; aOR, 0.17; 95% CI, 0.05-0.54). There were also significant reductions in perinatal mortality (27.6% vs 59.2%; aOR, 0.24; 95% CI, 0.11-0.5), neonatal intensive care unit admission (75.9% vs 97.6%; aOR, 0.07; 95% CI, 0.01-0.66), and composite adverse neonatal outcome (33.9% vs 90.5%; aOR, 0.05; 95% CI, 0.01-0.21).

CONCLUSION

Cerclage, indomethacin, and antibiotics in twin pregnancies with dilated cervix ≥1 cm before 24 weeks were associated with significant longer latency period from diagnosis to delivery (6.7 weeks), decreased incidence of spontaneous preterm birth at any given gestational age, and improved perinatal outcome when compared with expectant management.

Mono-(2-Ethylhexyl) Phthalate Promotes Pro-Labor Gene Expression in the Human Placenta

Women exposed to phthalates during pregnancy are at increased risk for delivering preterm, but the mechanism behind this relationship is unknown. Placental corticotropin-releasing hormone (CRH) and cyclooxygenase-2 (COX-2) are key mediators of parturition and are regulated by the non-canonical NF-kB (RelB/p52) signaling pathway. In this study, we demonstrate that one of the major phthalate metabolites, mono-(2-ethylhexyl)-phthalate (MEHP), increased CRH and COX-2 mRNA and protein abundance in a dose-dependent manner in primary cultures of cytotrophoblast. This was coupled with an increase in nuclear import of RelB/p52 and its association with the CRH and COX-2 promoters. Silencing of NF-kB inducing kinase, a central signaling component of the non-canonical NF-kB pathway, blocked MEHP-induced upregulation of CRH and COX-2. These results suggest a potential mechanism mediated by RelB/p52 by which phthalates could prematurely induce pro-labor gene activity and lead to preterm birth.

Science Signaling Podcast: 25 August 2015

A glucocorticoid-mediated epigenetic switch promotes placental production of a stress hormone associated with labor.

Comparative Immunohistochemistry of Placental Corticotropin-Releasing Hormone and the Transcription Factor RelB-NFκB2 Between Humans and Nonhuman Primates

The transcription factor RelB-NFκB2, activated by the noncanonical NFκB pathway, positively regulates corticotropin-releasing hormone (CRH) and prostaglandin production in the term human placenta and may play an important role in the timing of human parturition. Here we explored whether RelB-NFκB2 signaling plays a role in parturition in nonhuman anthropoid primates. We performed immunohistochemical staining to assess the correlation between CRH and nuclear activity of RelB-NFκB2 heterodimers in term placentas from humans, 3 catarrhine primate species, and a single platyrrhine primate species. Consistent with our previous studies, the human placenta showed cytoplasmic staining for CRH and nuclear staining for RelB-NFκB2. Similar staining patterns were noted in the 3 catarrhine primates (chimpanzee, baboon, and rhesus macaque). The platyrrhine (marmoset) placentas stained positively for CRH and RelB but not for NFκB2. Catarrhine (but not platyrrhine) nonhuman primate term placentas demonstrate the same CRH staining and nuclear localization patterns of RelB and NFκB2 as does human placenta. These results suggest that catarrhine primates, particularly rhesus macaques, may serve as useful animal models to study the biologic significance of the noncanonical NFκB pathway in human pregnancy.

STAT3 cooperates with the non-canonical NF-κB signaling to regulate pro-labor genes in the human placenta

INTRODUCTION

Our recent studies have shown that constitutively activated non-canonical RelB/NF-κB2 (p52) in the human placenta positively regulates the pro-labor genes CRH and COX-2. STAT3 regulates NF-κB2 (p100) processing to active p52, and in turn, nuclear activation of RelB/p52, by directly binding to p100/p52 in a variety of cancer cells. In the current study, we tested the hypothesis that STAT3 is involved in regulation of pro-labor genes by associating with RelB/p52 heterodimers in the human placenta.

METHODS

We used a variety of techniques including immunohistochemical staining, gene silencing, ectopic expression, chromatin immunoprecipitation, Western blot, RT-qPCR, and immunofluorescence assays in primary culture of cytotrophoblast and placental tissues.

RESULTS

We found that knockdown of STAT3 led to down-regulation of both CRH and COX-2 in a dose-dependent manner. By using chromatin immunoprecipitation, we further showed that interaction of RelB with the CRH or COX-2 gene promoters decreased when STAT3 was depleted. Immunofluorescence demonstrated co-localization of STAT3 with RelB or p100/p52 in both the cytoplasm and nucleus of term cytotrophoblasts.

DISCUSSION

Collectively, these results suggest that STAT3 constitutes part of the RelB/p52-containing activator complex that positively regulates pro-labor genes in the human placenta.

Negative effects of progesterone receptor isoform-A on human placental activity of the noncanonical NF-κB signaling

CONTEXT

Progesterone (P4)contributes to the maintenance of human pregnancy, in part by inhibiting activity of the human pro-labor genes CRH and cyclooxygenase-2 (COX-2). However, the molecular mechanisms underlying the action of P4 remain poorly defined. We have shown that in human placenta, the constitutively activated noncanonical nuclear factor (NF)-κB pathway positively regulates CRH and COX-2, which is further stimulated by glucocorticoid receptor signaling.

OBJECTIVE

We investigated the role of P4 receptor (PR) in the regulation of nuclear activity of v-rel avian reticuloendotheliosis viral oncogene homolog B (RelB)/NF-κB2 and, in turn, expression of placental CRH and COX-2.

METHODS

We used a variety of techniques including gene silencing, ectopic expression, chromatin immunoprecipitation, Western blot, quantitative RT-PCR, and immunohistochemical staining assays in human placental tissues and primary culture of human cytotrophoblast.

RESULTS

We identified PR isoform-A (PR-A) as the only isoform of PR produced in human placenta. PR-A levels were lower in term placenta than in midterm placenta. Depletion of PR-A by short interfering RNA derepressed inhibition of CRH and COX-2 by P4 and the synthetic progestin 17α-hydroxyprogesterone caproate. Overexpression of PR-A inhibited transcription of CRH and COX-2, which was further downregulated by treatment with P4 or 17α-hydroxyprogesterone caproate. Such an inhibition was mediated by a negative functional interaction of PR-A with the activity of RelB/NF-κB2.

CONCLUSION

P4 inhibits the pro-labor genes CRH and COX-2 via PR-A repression of the noncanonical NF-κB signaling in human placenta. Characterization of these pathways may identify potential drug targets for prevention of preterm birth.