A randomized controlled trial comparing the efficacy of nifedipine and enalapril in the postpartum period

BACKGROUND

Postpartum hypertension is a common medical complication of pregnancy and is associated with increased healthcare use, including unplanned interactions with the medical system and readmission, which can add significant stress to both a newly postpartum patient and the medical care delivery system. We currently do not know what the best antihypertensive treatment for postpartum hypertension is and tend to use antihypertensives commonly used during pregnancy. However, the mechanism of action of angiotensin-converting enzyme inhibitors may be well suited for the pathophysiology of hypertension in the postpartum period and may help to provide better control of hypertension and, in turn, decrease healthcare use.

OBJECTIVE

This study aimed to determine if enalapril is superior to nifedipine in preventing prolonged hospitalizations, unplanned medical visits, and/or readmission among women with postpartum hypertension.

STUDY DESIGN

We performed an open-label, randomized controlled trial (ClinicalTrials.gov registered: NCT04236258) in which patients ≥18 years with chronic hypertension, gestational hypertension, or preeclampsia were recruited to receive either 10 mg enalapril daily or 30 mg extended-release nifedipine daily as an initial antihypertensive agent in the period from delivery to 6 weeks postpartum. Recruitment occurred at a tertiary academic hospital from January 2020 to February 2021. Exclusion criteria included being on an antihypertensive when pregnancy started or requiring ≥2 daily antihypertensives during pregnancy. The antihypertensive regimen was managed by the participants' obstetrical provider after the initial randomization. The primary outcome was a composite of prolonged hospitalization, unplanned clinic visits, triage visits, and/or readmission. A total of 40 patients in each arm were needed to detect a decrease in the primary outcome rate from 70% to 40% (α=0.05; power 0.80). Analyses were performed based on the intention-to-treat principal, and each arm was oversampled because of the risk for participant dropout.

RESULTS

A total of 47 patients were randomized to each arm. Aside from the mode of delivery and twin gestation, the maternal demographics were similar between the 2 groups. The primary outcome occurred in 31 of 47 patients (66%) randomized to the nifedipine group and in 30 of 47 (64%) randomized to the enalapril group (P=.83). There was no significant difference in the primary outcome after controlling for mode of delivery and twin gestation. More patients in the enalapril arm had a second antihypertensive added during their primary hospitalization (16 vs 6) and more patients in the nifedipine arm were still on their antihypertensive at 2 weeks postpartum (42 vs 36). There were no adverse events in either group.

CONCLUSION

Enalapril was not superior to nifedipine when used as an initial antihypertensive in the immediate postpartum period in terms of decreasing healthcare use.

Intrapartum ultrasound measurement of angle of progression at the onset of the second stage of labor for prediction of spontaneous vaginal delivery in term singleton pregnancies: a systematic review and meta-analysis

OBJECTIVE

This study aimed to investigate the diagnostic performance of transperineal ultrasound-measured angles of progression at the onset of the second stage of labor for the prediction of spontaneous vaginal delivery in singleton term pregnancies with cephalic presentation.

DATA SOURCES

We performed a predefined systematic search in PubMed, Embase, Scopus, Web of Science, and Google Scholar from inception to February 5, 2021.

STUDY ELIGIBILITY CRITERIA

Prospective cohort studies that evaluated the diagnostic performance of transperineal ultrasound-measured angles of progression (index test) at the onset of the second stage of labor (ie, when complete cervical dilation is diagnosed) for the prediction of spontaneous vaginal delivery (reference standard) were eligible for inclusion. Eligible studies were limited to those published as full-text articles in the English language and those that included only parturients with a singleton healthy fetus at term with cephalic presentation.

STUDY APPRAISAL AND SYNTHESIS METHODS

Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Summary receiver operating characteristic curves, pooled sensitivities and specificities, area under the curve, and summary likelihood ratios were calculated using the Stata software. Subgroup analyses were done based on angle of progression ranges of 108° to 119°, 120° to 140°, and 141° to 153°.

RESULTS

A total of 8 studies reporting on 887 pregnancies were included. Summary estimates of the sensitivity and specificity of transperineal ultrasound-measured angle of progression at the onset of the second stage of labor for predicting spontaneous vaginal delivery were 94% (95% confidence interval, 88%-97%) and 47% (95% confidence interval, 18%-78%), respectively, for an angle of progression of 108° to 119°, 81% (95% confidence interval, 70%-89%) and 73% (95% confidence interval, 57%-85%), respectively, for an angle of progression of 120° to 140°, and 66% (95% confidence interval, 56%-74%) and 82% (95% confidence interval, 66%-92%), respectively, for an angle of progression of 141° to 153°. Likelihood ratio syntheses gave overall positive likelihood ratios of 1.8 (95% confidence interval, 1-3.3), 3 (95% confidence interval, 2-4.7), and 3.7 (95% confidence interval, 1.7-8.1) and negative likelihood ratios of 0.13 (95% confidence interval, 0.07-0.22), 0.26 (95% confidence interval, 0.18-0.38), and 0.42 (95% confidence interval, 0.29-0.60) for angle of progression ranges of 108° to 119°, 120° to 140°, and 141° to 153°, respectively.

CONCLUSION

Angle of progression measured by transperineal ultrasound at the onset of the second stage of labor may predict spontaneous vaginal delivery in singleton, term, cephalic presenting pregnancies and has the potential to be used along with physical examinations and other clinical factors in the management of labor and delivery.

Changes in Delivery Timing for High-Risk Pregnancies in the United States

OBJECTIVE

This study was aimed to assess whether the "39-week" rule is being extended to high-risk pregnancies and if so whether this has led to changes in neonatal morbidity or stillbirth.

STUDY DESIGN

Birth certificate data between 2010 and 2014 from 23 states (55% of births in the United States) were used. Pregnancies were classified as high risk if they had any one of the following: maternal age greater than or equal to 40 years, prepregnancy body mass index (BMI) greater than or equal to 40 kg/m², chronic (prepregnancy) hypertension, or diabetes (pregestational or gestational). Delivery timing changes for all pregnancies at term (37 weeks or greater) were compared with changes in the high-risk population. Neonatal morbidities (neonatal intensive care unit [NICU] admission, need for assisted ventilation, 5-minute Apgar score, and macrosomia), maternal morbidities (intensive care unit [ICU] admission, cesarean delivery, operative vaginal delivery, chorioamnionitis, and severe perineal laceration), and stillbirth rates were compared across time periods. Multivariate logistic regression was used to analyze whether gestational age-specific morbidity changes were due to shifts in delivery timing.

RESULTS

For the overall population, there was a shift in delivery timing between 2010 and 2014, a 2.5% decrease in 38-week deliveries, and a 2.3% increase in 39-week deliveries (p < 0.01). This gestational age shift was identical in the high-risk population (2.7% decrease in 38-week deliveries and 2.9% increase in 39-week deliveries). For the high-risk population, NICU admission increased from 5.4 to 6.3% in 2014 (p < 0.01) and assisted ventilation rates declined from 3.8 to 2.9% (p < 0.01). These changes, however, were independent of changes in delivery timing. There was no increase in the rate of stillbirth (0.23% in 2010 and 0.23% in 2014; p = 0.50).

CONCLUSION

There was a significant shift in delivery timing for high-risk pregnancies in the United States between 2010 and 2014. This shift, however, did not result in statistically significant changes in either neonatal morbidity or stillbirth.

KEY POINTS

· From 2010 to 2014, term deliveries for high-risk pregnancies shifted towards 39 weeks.. · The shift towards 39 weeks in high-risk pregnancies was not accompanied by any improvement in neonatal morbidity.. · The shift towards 39 weeks in high-risk pregnancies did not result in an increase in the stillbirth rate..

Association between morbidity among term newborns and low-risk caesarean delivery rates

OBJECTIVE

To examine the association between county-level caesarean delivery (CD) rates among women at low risk and morbidity among term newborns.

DESIGN

Cross-sectional study.

SETTING

Population-based study of US county-level birth data from 2015 to 2017.

POPULATION

Nulliparous women with term, singleton, vertex-presenting infants (NTSV) at low risk for morbidity.

METHODS

The primary exposure was county-level CD rates.

MAIN OUTCOME MEASURES

The outcome was morbidity among the low-risk NTSV cohort, categorised as severe (5-minute Apgar score of ≤3, assisted ventilation for ≥6 hours, severe neurologic injury or seizure, transfer or death) or moderate (5-minute Apgar score of <7 but >3, administration of antibiotics or assisted ventilation at delivery). We used linear regression models to determine the association between county NTSV CD and neonatal morbidity rates with cluster robust standard errors.

RESULTS

The analysis included data from 2 753 522 births in 952 counties from all 48 states. The mean NTSV CD rate was 23.6% (standard deviation 4.8%). The median severe and moderate neonatal morbidity rates were 15.2 (interquartile range, IQR 9.4-23.6) and 52.5 (IQR 33.4-75.7) per 1000 births, respectively. In the unadjusted analysis using the risk-adjusted exposure and outcome, every percentage point increase in the CD rate of a county was associated with 0.6 (95% CI -0.9, -0.3) and 2.3 fewer (95% CI -3.4, -1.1) cases of severe and moderate neonatal morbidity per 1000 live births. After adjustment for other county factors, the relationships remained significant. These findings were tested in multiple sensitivity analyses.

CONCLUSIONS

Lower county-level NTSV CD rates were associated with a small increase in morbidity among term newborns in the USA.

TWEETABLE ABSTRACT

Lower county-level caesarean delivery rates were associated with an increase in morbidity among term newborns in the USA.

Association between hospital-level cesarean delivery rates and severe maternal morbidity and unexpected newborn complications

BACKGROUND

Although there are many indications for a cesarean delivery, the "optimal" cesarean delivery rate is unknown. Neonatal and maternal morbidity have largely not been considered in the generation of hospital-level cesarean delivery rate targets.

OBJECTIVE

We sought to examine if the widely adopted and reported markers of maternal and neonatal morbidity were associated with hospital cesarean delivery rates to provide context for potential comparison and consideration for defining cesarean delivery rate targets. We hypothesized that hospitals with higher cesarean delivery rates would have increased rates of severe maternal morbidity, though we were less certain of the associations of the cesarean delivery rates with unexpected newborn complications.

STUDY DESIGN

This is a cross-sectional, ecological study using data from the 2016 Nationwide Readmission Database of hospitals with at least 100 deliveries per year. The exposure of interest was hospital cesarean delivery rate. The outcomes were (1) severe maternal morbidity with and without transfusion-in accordance with the Centers for Disease Control and Prevention's definition, and (2) neonatal morbidity-defined using The Joint Commission's Perinatal Quality metric of moderate and severe unexpected newborn complications among term, singleton, and nonanomalous neonates. Before assuming a single linear relationship to model the associations between morbidity and cesarean delivery rates, the Joinpoint Regression Analysis program was used to examine for potential splines in the relationships with both severe maternal morbidity (with and without transfusion) and severe and moderate unexpected newborn complications. Poisson regression model was then used to determine the association between morbidity and cesarean delivery rates.

RESULTS

The analysis included 831,111 deliveries from 621 hospitals. The mean cesarean delivery rate was 30.5%. The median severe maternal morbidity rate was 1.40 per 100 deliveries (interquartile range, 0.71-2.21 per 1000 deliveries). Excluding transfusion, the median severe maternal morbidity rate was 0.47 per 100 deliveries (interquartile range, 0.22-0.73 per 100 deliveries). The median rate of severe and moderate unexpected newborn complications was 1.01 per 100 low-risk newborns (interquartile range, 0.64-1.69 per 100 low-risk newborns) and 1.79 per 1000 low-risk newborns (interquartile range, 0.94-2.93 per 100 low-risk newborns), respectively. In the unadjusted analysis, every percentage point increase in a hospital's cesarean delivery rate was associated with a 3.4% (95% confidence interval, 2.3%-4.4%) and a 2.3% (95% confidence interval, 1.0%-3.5%) increase in severe maternal morbidity including and excluding transfusion, respectively. After adjustment for the case mix and hospital factors, only the relationship with severe maternal morbidity including transfusion remained significant: 3.3% (95% confidence interval, 1.7%-4.9%) increase in severe maternal morbidity per 1 percentage point increase in the cesarean delivery rate. There was no observed association between cesarean delivery rates and unexpected newborn complications CONCLUSION: Severe maternal morbidity and unexpected newborn complications occur in fewer than 5 in 100 births. Findings from this analysis of hospitals with cesarean delivery rates ranging from 6.8%-56.3% suggest that those with lower cesarean delivery rates have lower severe maternal morbidity (which includes transfusion) and similar unexpected newborn complications compared with hospitals with higher cesarean delivery rates. This work may provide a helpful context to providers, hospitals, and policymakers who are measuring and reporting outcomes. Regarding neonatal morbidity in particular, the Joint Commission manual notes that the unexpected newborn complication metric was specifically designed to be compared against maternal-focused metrics such as cesarean delivery rates. More work is needed to define and identify appropriate measures of maternal and neonatal morbidity for these types of comparisons.

Provider Attitudes on Regionalization of Maternity Care: A National Survey

OBJECTIVES

To explore provider perspectives surrounding national guidelines proposing regionalization of maternal care.

METHODS

An 18-item survey focused on provider attitudes and practices surrounding regionalized maternity care was administered to a national sample of practicing obstetricians. We classified respondants reporting less than 500 annual deliveries at their hospital as low-volume providers and those practicing at hospitals performing 500 or more annual deliveries as high-volume providers. We compared responses according to hospital delivery volume using univariate analysis.

RESULTS

Of the 497 physicians surveyed, 278 people responded (56%) with 229 currently practicing obstetrics. The median annual delivery volume amongst respondents was 200 (interquartile range 100-1900) with 146 (63.7%) practicing in low-volume delivery centers. The need for medical or surgical expertise was the most commonly reported indication for maternal transfer (19.7%) and independent of practice setting. Ninety-six percent of providers agreed with the concept of regionalization, but respondents in high-volume centers reported higher familiarity with the levels of maternal care paradigm compared to their low-volume counterparts (81.9% v. 62.3%, p < 0.01). Financial factors (60.3%), geography (48.9%), and access to care (43.2%) were the most cited major barriers to regionalization. High-volume providers endorsed geography as a major barrier more often than low-volume providers (57.8% v. 43.8%, p = 0.04).

CONCLUSIONS FOR PRACTICE

Obstetricians may agree with the concept of regionalized maternity care but also identify significant barriers to its implementation. Early and frequent engagement of providers reflecting the diversity of delivery centers in a region is a simple but necessary step in any attempts to designate levels of maternal care.

Psychiatric Conditions During Pregnancy and Postpartum in a Universally Insured American Population

BACKGROUND

Mental health conditions are common and can have significant effects during the perinatal period. Our objective was to determine the incidences and predictors of psychiatric conditions during pregnancy and postpartum among universally insured American women.

MATERIAL AND METHODS

This was an Institutional Review Board (IRB)-approved protocol using a retrospective cohort of 104,866 deliveries covered by TRICARE from 2005 to 2014. We used TRICARE claims data to identify pregnant women without current psychiatric conditions who developed new psychiatric condition(s) during pregnancy or postpartum compared with those who did not, as identified by International Classification of Diseases (ICD)-9 CM codes. Predictors of psychiatric conditions during pregnancy or postpartum were determined using stepwise logistic regression models.

RESULTS

A total of 104,866 women met the inclusion criteria; of these, 35% (n = 36,192) were diagnosed with a new psychiatric condition during pregnancy or within 1 year of delivery, 15% (n = 15,636) with a psychiatric condition during pregnancy, and 20% (n = 20,556) with a psychiatric condition within 1 year of delivery. We demonstrated that the African-American race (odds ratio [OR] 1.16, 95% CI 1.10-1.22), active duty status (OR 1.20, 95% CI 1.14-1.25), and severe maternal morbidity during delivery (OR 1.18, 95% CI 1.02-1.35) were significantly associated with the occurrence of a psychiatric condition within 1 year of delivery. For Asian women, there was a 28% higher odds of developing a psychiatric disorder during pregnancy (adjusted OR 1.28, 95% CI 1.17-1.40) compared with White women. Active duty women were twice as likely to be diagnosed with post-traumatic stress disorder (adjusted OR 2.31, 95% CI 1.83-2.90).

CONCLUSION

In a universally insured population, the incidences of psychiatric conditions in pregnancy and within a year of delivery were similar to the American population. Additionally, the development of psychiatric conditions in pregnancy and within a year of delivery may be associated with race, active duty status, and complicated births.

The interrater reliability and agreement of a 0 to 10 uterine tone score in cesarean delivery

BACKGROUND

Postpartum hemorrhage is a leading source of maternal morbidity and mortality worldwide with uterine atony identified as the underlying cause in up to 80% of cases. Several measures have been utilized to report uterine tone. The most commonly reported measure is a 0 to 10 numeric rating scale, but this scale has not been tested for reliability or agreement between different raters.

OBJECTIVE

The primary purpose of this study was to evaluate the interrater reliability and agreement of the 0 to 10 visual numeric rating scale of uterine tone during cesarean delivery. A secondary purpose was to obtain estimates of scale responsiveness and minimal clinically important difference.

STUDY DESIGN

Between August and November of 2018, obstetricians used a 0 to 10 numeric rating score to independently rate uterine tone at 3 and 10 minutes after cesarean delivery by palpation of the uterus. Of note, "0" represented "no tone" and "10" represented excellent tone. Each obstetrician independently and blinded to the other's score pointed to a numeric rating scale held by the anesthesiologist through a clear sterile drape. Intraclass correlation coefficients and Bland-Altman analysis were used to assess interrater reliability and agreement, respectively. Standardized response mean and standard error of measurement were used to obtain estimates of responsiveness and minimal clinically important difference, respectively.

RESULTS

A total of 82 and 84 pairs of scores were collected at 3 and 10 minutes, respectively, from pairs of 62 unique obstetricians. The mean±standard deviation difference in scores between rater 1 and rater 2 was 0.4±1.4 at 3 minutes and 0.1±1.1 at 10 minutes. Intraclass correlation coefficients for a future single rater (intraclass correlation coefficient [1, 1]) at 3 and 10 minutes were 0.67 (95% confidence interval, 0.53-0.77) and 0.61 (95% confidence interval, 0.46-0.73), and for the average between 2 future raters (intraclass correlation coefficient [1, 2]), they were 0.80 (95% confidence interval, 0.71-0.87) and 0.76 (95% confidence interval, 0.63-0.84), indicating good and excellent reliability, respectively. Bland-Altman analysis estimated 95% limit of agreement between raters of -2.4 (95% confidence interval, -3.0 to -1.9) to 3.1 (95% confidence interval, 2.6-3.7) at 3 minutes and -2.1 (95% confidence interval, -2.5 to -1.7) to 2.4 (95% confidence interval, 2.0-2.8) at 10 minutes, consistent with good interrater agreement at both time points. The standardized response mean from 3 to 10 minutes after delivery was 1.1 (n=81). Standard error of measurement was 1.0 (95% confidence interval, 0.9-1.1) at 3 minutes and 0.8 (95% confidence interval, 0.7-0.9) at 10 minutes.

CONCLUSION

The 0 to 10 numeric rating scale for uterine tone demonstrated good to excellent interrater reliability with 1 and 2 raters, respectively, and good interrater agreement. The scale was responsive to within-parturient change in tone, and preliminary estimates of the minimal clinically important difference were obtained. The 0 to 10 numeric rating scale for uterine tone may be a reliable, standardized tool for future research in reporting degree of uterotonic contraction during cesarean delivery.

Patient characteristics associated with SARS-CoV-2 infection in parturients admitted for labour and delivery in Massachusetts during the spring 2020 surge: A prospective cohort study

BACKGROUND

While studies from large cities affected by coronavirus disease 2019 (COVID-19) have reported on the prevalence of SARS-CoV-2 in the context of universal testing during admission for delivery, the patient demographic, social and clinical factors associated with SARS-CoV-2 infection in pregnant women are not fully understood.

OBJECTIVE

To evaluate the epidemiological factors associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in women admitted for labour and delivery, in the context of universal screening at four Boston-area hospitals.

METHODS

In this prospective cohort study, we reviewed the health records of all women admitted for labour and delivery at four hospitals from the largest health system in Massachusetts between 19 April 2020 and 27 June 2020. We calculated the risk of SARS-CoV-2 infection, including asymptomatic infection. We calculated associations between SARS-CoV-2 infection and demographic and clinical characteristics.

RESULTS

A total of 93 patients (3.2%, 95% confidence interval 2.5, 3.8) tested positive for SARS-CoV-2 infection on admission for labour and delivery out of 2945 patients included in the analysis; 80 (86.0%) of the patients who tested positive were asymptomatic at the time of testing. Factors associated with SARS-CoV-2 infection included the following: younger age, obesity, African American or Hispanic race/ethnicity, residence in heavily affected communities (as measured in cases reported per capita), presence of a household member with known SARS-CoV-2 infection, non-health care essential worker occupation and MassHealth or Medicaid insurance compared to commercial insurance. 93.8% of patients testing positive for SARS-CoV-2 on admission had one or more identifiable factors associated with disease acquisition.

CONCLUSIONS

In this large sample of deliveries during the height of the surge in infections during the spring of 2020, SARS-CoV-2 infection was largely concentrated in patients with distinct demographic characteristics, those largely from disadvantaged communities. Racial disparities seen in pregnancy persist with respect to SARS-CoV-2 infection.

Placental MRI: Effect of maternal position and uterine contractions on placental BOLD MRI measurements

INTRODUCTION

Before using blood-oxygen-level-dependent magnetic resonance imaging (BOLD MRI) during maternal hyperoxia as a method to detect individual placental dysfunction, it is necessary to understand spatiotemporal variations that represent normal placental function. We investigated the effect of maternal position and Braxton-Hicks contractions on estimates obtained from BOLD MRI of the placenta during maternal hyperoxia.

METHODS

For 24 uncomplicated singleton pregnancies (gestational age 27-36 weeks), two separate BOLD MRI datasets were acquired, one in the supine and one in the left lateral maternal position. The maternal oxygenation was adjusted as 5 min of room air (21% O₂), followed by 5 min of 100% FiO₂. After datasets were corrected for signal non-uniformities and motion, global and regional BOLD signal changes in R₂* and voxel-wise Time-To-Plateau (TTP) in the placenta were measured. The overall placental and uterine volume changes were determined across time to detect contractions.

RESULTS

In mothers without contractions, increases in global placental R₂* in the supine position were larger compared to the left lateral position with maternal hyperoxia. Maternal position did not alter global TTP but did result in regional changes in TTP. 57% of the subjects had Braxton-Hicks contractions and 58% of these had global placental R₂* decreases during the contraction.

CONCLUSION

Both maternal position and Braxton-Hicks contractions significantly affect global and regional changes in placental R₂* and regional TTP. This suggests that both factors must be taken into account in analyses when comparing placental BOLD signals over time within and between individuals.

Using Cervical Dilation to Predict Labor Onset: A Tool for Elective Labor Induction Counseling

OBJECTIVE

To evaluate whether cervical dilation predicts the timing and likelihood of spontaneous labor at term.

STUDY DESIGN

This was a retrospective cohort of nulliparous women with singleton pregnancies who delivered at term from 2013 to 2015. Outpatient cervical examinations performed after 37 weeks and prior to labor onset were collected. Survival analysis was used to analyze time to spontaneous labor with cervical dilation as the primary predictor, modeled as continuous and categorical variables (<1 cm, 1 cm, >1 cm).

RESULTS

Our cohort included 726 women; 407 (56%) spontaneously labored, 263 (36%) were induced, and 56 (8%) had an unlabored cesarean delivery. Women with >1-cm dilation were three times more likely to spontaneously labor (adjusted hazard ratio [aHR]: 3.1; 95% confidence interval [CI]: 2.4-4) than those with <1-cm dilation. At 39 weeks, 60% of women with >1-cm dilation went into spontaneous labor as compared with only 28% of those with <1-cm dilation (aHR: 2.9; 95% CI: 2-4.4).

CONCLUSION

In our cohort of nulliparous women at term, those with cervical dilation > 1 cm were significantly more likely to go into labor in the following week. This information can aid in counseling about elective induction of labor.

Preliminary evaluation of dynamic glucose enhanced MRI of the human placenta during glucose tolerance test

Background

To investigate dynamic glucose enhanced (DGE) chemical exchange saturation transfer (CEST) MRI as a means to non-invasively image glucose transport in the human placenta.

Methods

Continuous wave (CW) CEST MRI was performed at 3.0 Tesla. The glucose contrast enhancement (GCE) was calculated based on the magnetization transfer asymmetry (MTRasym), and the DGE was calculated with the positive side of Z-spectra in reference to the first time point. The glucose CEST (GlucoCEST) was optimized using a glucose solution phantom. Glucose solution perfused ex vivo placenta tissue was used to demonstrate GlucoCEST MRI effect. The vascular density of ex vivo placental tissue was evaluated with yellow dye after MRI scans. Finally, we preliminarily demonstrated GlucoCEST MRI in five pregnant subjects who received a glucose tolerance test. For human studies, the dynamic R2* change was captured with T2*-weighted echo planar imaging (EPI).

Results

The GCE effect peaks at a saturation B1 field of about 2 μT, and the GlucoCEST effect increases linearly with the glucose concentration between 4-20 mM. In ex vivo tissue, the GlucoCEST MRI was sensitive to the glucose perfusate and the placenta vascular density. Although the in vivo GCE baseline was sensitive to field inhomogeneity and motion artifacts, the temporal evolution of the GlucoCEST effect showed a consistent and positive response after oral glucose tolerance drink.

Conclusions

Despite the challenges of placental motion and field inhomogeneity, our study demonstrated the feasibility of DGE placenta MRI at 3.0 Tesla.

Placental MRI: Developing Accurate Quantitative Measures of Oxygenation

The Human Placenta Project has focused attention on the need for noninvasive magnetic resonance imaging (MRI)-based techniques to diagnose and monitor placental function throughout pregnancy. The hope is that the management of placenta-related pathologies would be improved if physicians had more direct, real-time measures of placental health to guide clinical decision making. As oxygen alters signal intensity on MRI and oxygen transport is a key function of the placenta, many of the MRI methods under development are focused on quantifying oxygen transport or oxygen content of the placenta. For example, measurements from blood oxygen level-dependent imaging of the placenta during maternal hyperoxia correspond to outcomes in twin pregnancies, suggesting that some aspects of placental oxygen transport can be monitored by MRI. Additional methods are being developed to accurately quantify baseline placental oxygenation by MRI relaxometry. However, direct validation of placental MRI methods is challenging and therefore animal studies and ex vivo studies of human placentas are needed. Here we provide an overview of the current state of the art of oxygen transport and quantification with MRI. We suggest that as these techniques are being developed, increased focus be placed on ensuring they are robust and reliable across individuals and standardized to enable predictive diagnostic models to be generated from the data. The field is still several years away from establishing the clinical benefit of monitoring placental function in real time with MRI, but the promise of individual personalized diagnosis and monitoring of placental disease in real time continues to motivate this effort.

A comorbidity-based screening tool to predict severe maternal morbidity at the time of delivery

BACKGROUND

The obstetric comorbidity index summarizes the burden of maternal comorbidities into a single number and holds promise as a maternal risk-assessment tool.

OBJECTIVE

The aim of this study was to assess the clinical performance of this comorbidity-based screening tool to accurately identify women on labor and delivery who are at risk of severe maternal morbidity on labor and delivery in real time.

STUDY DESIGN

All patients with pregnancies ≥23 weeks gestation presenting to labor and delivery at a single tertiary-care center from February through July 2018 were included in the study. The patient's primary labor and delivery nurse assessed patient comorbidities and calculated the patient's obstetric comorbidity index. The score was recalculated at each 12-hour shift change. A multidisciplinary panel of clinicians determined whether patients experienced severe maternal morbidity based on the American College of Obstetrics and Gynecology and Society for Maternal-Fetal Medicine consensus definition, blinded to the patient's obstetric comorbidity index score. We analyzed the association between the obstetric comorbidity index score and the occurrence of severe maternal morbidity.

RESULTS

The study included 2828 women, of whom 1.73% experience severe maternal morbidity (n=49). The obstetric comorbidity index ranged from 0-15 for women in the study cohort, with a median obstetric comorbidity index of 1 (interquartile range, 0-3). The median obstetric comorbidity index score for women who experienced the severe maternal morbidity was 5 (interquartile range, 3-7) compared with a median of 1 (interquartile range, 0-3) for those without severe maternal morbidity (P<.01). The frequency of severe maternal morbidity increased from 0.41% for those with a score of 0 to 18.75% for those with a score ≥9. For every 1-point increase in the score, patients experienced a 1.55 increase in odds of severe maternal morbidity (95% confidence interval, 1.42-1.70). The c-statistic for the obstetric comorbidity index score was 0.83 (95% confidence interval, 0.76-0.89), which indicated strong discrimination.

CONCLUSION

The obstetric comorbidity index can prospectively identify women at risk of severe maternal morbidity in a clinical setting. A particular strength of the obstetric comorbidity index is its ability to integrate multiple compounding comorbidities and highlight the cumulative risk that is associated with the patients' conditions. Routine clinical use of the obstetric comorbidity index has the potential to identify at-risk women whose condition warrants increased surveillance and targeted care to prevent adverse maternal outcomes.

Relationship between endogenous melatonin concentrations and uterine contractions in late third trimester of human pregnancy

In humans, circulating levels of the hormone melatonin and the initiation of spontaneous labor are both higher at night than during the day. Since activation of uterine melatonin receptors can stimulate human in vitro uterine contractions and these receptors are only expressed on the uterine tissue of women in labor, we hypothesized that circulating melatonin concentrations would affect uterine contractions in vivo. We evaluated the impact of light-induced modulation of melatonin secretion on uterine contractions in women during late third trimester (~36-39 weeks) of pregnancy in two inpatient protocols. We found a significant (P < 0.05) positive linear association between circulating melatonin concentrations and the number of uterine contractions under both protocols. On average, uterine contractions increased between 1.4 and 2.1 contractions per 30 minutes for every 10 pg/mL*h increase in melatonin concentration. These findings have both basic science and clinical implications for pregnant women, since endogenous melatonin levels and melatonin receptor activity can be altered by light and/or pharmaceutical agents.

Timing of Antenatal Corticosteroid Administration in Monoamniotic Twins

Objective  This study was aimed to determine if different strategies of antenatal corticosteroid (ACS) administration in monoamniotic twins leads to receipt within 7 days of delivery. Study Design  This is a retrospective cohort of monoamniotic twins managed at a single institution from 2007 to 2017. Patients were classified as to whether ACS were administered upon admission or at a predetermined gestational age (grouped together as "routine") or for a change in clinical status ("indicated"). We used univariate analyses to associate ACS administration strategies with our primary outcome: receipt of ACS within 7 days of delivery. We then used generalized estimating equations to examine associations between fetal monitoring patterns and delivery within 1 week. Results  Twenty-four patients were included: eighteen patients in the "routine" group and six patients in the "indicated" group. There was no difference in optimal timing of ACS administration. Women experiencing delivery within the week were thrice more likely to spend on average more than 3 hours/day on the fetal monitor when compared with those who remained undelivered. Conclusion  Administration of ACS on admission is not effective. Fetal heart rate tracing surveillance might be a better methodology to predict delivery and guide ACS administration.

Use of a Fibrin Sealant Patch at Cesarean for Conservative Management of Morbidly Adherent Placenta

Background  Morbidly adherent placenta represents a surgical challenge and source of maternal morbidity and mortality. We report the use of a fibrin sealant patch to address hemorrhage associated with a morbidly adherent placenta during cesarean delivery. Case  A patient underwent repeat cesarean delivery with complete anterior placenta previa and anticipated morbidly adherent placenta. Bleeding persisted following delivery and removal of the placenta, despite uterine artery embolization. A fibrin sealant patch was applied as an adjuvant intervention to the placental bed and hemostasis was achieved without resorting to a hysterectomy. Conclusion  Postpartum hemorrhage is an ongoing leading source of maternal morbidity and mortality. A case is presented in which a fibrin sealant patch provided control of focal placental bed bleeding, allowing removal of a focal morbidly adherent placenta and avoidance of hysterectomy.

Obstetric History and Likelihood of Preterm Birth of Twins

OBJECTIVE

The objective of this study was to investigate the relationship between preterm birth in a prior pregnancy and preterm birth in a twin pregnancy.

STUDY DESIGN

We performed a secondary analysis of a randomized controlled trial evaluating 17-α-hydroxyprogesterone caproate in twins. Women were classified as nulliparous, multiparous with a prior term birth, or multiparous with a prior preterm birth. We used logistic regression to examine the odds of spontaneous preterm birth of twins before 35 weeks according to past obstetric history.

RESULTS

Of the 653 women analyzed, 294 were nulliparas, 310 had a prior term birth, and 49 had a prior preterm birth. Prior preterm birth increased the likelihood of spontaneous delivery before 35 weeks (adjusted odds ratio [aOR]: 2.44, 95% confidence interval [CI]: 1.28-4.66), whereas prior term delivery decreased these odds (aOR: 0.55, 95% CI: 0.38-0.78) in the current twin pregnancy compared with the nulliparous reference group. This translated into a lower odds of composite neonatal morbidity (aOR: 0.38, 95% CI: 0.27-0.53) for women with a prior term delivery.

CONCLUSION

For women carrying twins, a history of preterm birth increases the odds of spontaneous preterm birth, whereas a prior term birth decreases odds of spontaneous preterm birth and neonatal morbidity for the current twin pregnancy. These results offer risk stratification and reassurance for clinicians.

Outcomes of Spontaneous Labor in Women Undergoing Trial of Labor after Cesarean as Compared with Nulliparous Women: A Retrospective Cohort Study

OBJECTIVE

The objective of this study was to compare spontaneous labor outcomes in women undergoing trial of labor after cesarean (TOLAC) and nulliparas to better counsel women.

STUDY DESIGN

A 4-year retrospective cohort. We included women at term in spontaneous labor with vertex singletons and no more than one prior cesarean delivery. In planned secondary analysis, we focused on a subset of women with a prior cesarean and a predicted likelihood of a successful vaginal delivery of 70% or more based on the Maternal-Fetal Medicine Units-vaginal birth after cesarean (VBAC) calculator.

RESULTS

Our cohort included 606 TOLACS and 606 nulliparas. Women undergoing TOLAC were more likely to undergo cesarean delivery (25.7 vs. 14.7%; p < 0.001). Severe maternal hemorrhage (1.5 vs. 0.2%; p = 0.02) and uterine rupture (1.9 vs. 0.0%; p < 0.01) were more likely in the TOLAC group. For the subset of women with a predicted likelihood of VBAC of 70% or more, there were no differences in cesarean delivery (16.7 vs. 14.7%; p = 0.51), maternal, or immediate neonatal complications.

CONCLUSION

Women undergoing TOLAC were more likely to have a cesarean delivery, hemorrhage, or uterine rupture. Those with more than 70% predicted likelihood of VBAC were no more likely to experience these outcomes. These findings help contextualize the risks of TOLAC for women considering this option.

The relative effects of patient and hospital factors on postpartum readmissions

OBJECTIVE

To determine the relative effects of patient and hospital factors on a hospital's postpartum readmission rate.

STUDY DESIGN

This retrospective cohort study was conducted using State Inpatient Databases from California, Florida, and New York between 2004 and 2013. We compared patient and hospital characteristics among hospitals with low and high readmission rates using χ² tests. Risk-adjusted 30-day readmission rates were calculated for patient, delivery, and hospital characteristics to understand factors affecting readmission using fixed and random effects models.

RESULTS

Patients in hospitals with low readmission rates were more likely to be white, to have private insurance and higher incomes, and to have fewer comorbidities. The patient comorbidities with the highest risk-adjusted readmission rates included hypertension (range, 2.14-3.04%), obesity (1.78-2.94%), preterm labor/delivery (2.50-2.60%), and seizure disorder (1.78-3.35%). Delivery complications were associated with increased risk-adjusted readmission rates. Compared to patient characteristics, hospital characteristics did not have a profound impact on readmission risk.

CONCLUSION

Obstetric readmissions were more attributable to patient and demographic characteristics than to hospital characteristics. Readmission metric-based incentives may ultimately penalize hospitals providing high-quality care due to patient characteristics specific to their catchment area.

Angle of Progression on Ultrasound in the Second Stage of Labor and Spontaneous Vaginal Delivery

OBJECTIVE

 The objective of this study was to assess the association between the angle of progression (AoP) measured by transperineal ultrasound and mode of delivery and duration of the second stage.

STUDY DESIGN

 This is a prospective observational study of nulliparous women with a singleton gestation at term in which serial transperineal ultrasound examinations were obtained during the second stage of labor. Multivariable logistic regression and adjusted survival models were used for the analysis.

RESULTS

 A total of 137 patients were included in the analysis and median AoP for the study group was 153 degrees. The adjusted odds ratio (aOR) of requiring an operative delivery was 2.6 times higher for those patients who had an AoP < 153 degrees and the aOR of requiring a cesarean delivery was almost six times higher when compared with those patients who had an AoP ≥ 153 degrees (95% confidence interval [CI]: 1.0, 6.2; p = 0.04; aOR: 5.8, 95% CI: 1.2-28.3; p = 0.03, respectively). Those patients with an AoP < 153 degrees were at a higher hazard of staying pregnant longer (adjusted hazard ratio: 1.8, 95% CI: 1.2-2.8, p = 0.005).

CONCLUSION

 The AoP has the potential to predict spontaneous vaginal delivery and the duration of the second stage of labor which may be useful in counseling patients and managing their labor.

The U.S. Twin Delivery Volume and Association with Cesarean Delivery Rates: A Hospital-Level Analysis

OBJECTIVE

 The objective of this study was to test whether hospitals experienced in twin delivery have lower rates of cesarean delivery for twins.

METHODS

 We divided obstetric hospitals in the 2011 National Inpatient Sample by quartile of annual twin deliveries and compared twin cesarean delivery rates between hospitals with weighted linear regression. We used Pearson's coefficients to correlate a hospital's twin cesarean delivery rate to its overall cesarean delivery and vaginal birth after cesarean (VBAC) rates.

RESULTS

 Annual twin delivery volume ranged from 1 to 506 across the 547 analyzed hospitals with a median of 10 and mode of 3. Adjusted rates of cesarean delivery were independent of delivery volume with a rate of 75.5 versus 74.8% in the lowest and highest volume hospitals (p = 0.09 across quartiles). A hospital's cesarean delivery rate for twins moderately correlated with the overall cesarean rate (r = 0.52, p < 0.01) and inversely correlated with VBAC rate (r =  - 0.42, p < 0.01).

CONCLUSION

 Most U.S. obstetrical units perform a low volume of twin deliveries with no decrease in cesarean delivery rates at higher volume hospitals. Twin cesarean delivery rates correlate with other obstetric parameters such as singleton cesarean delivery and VBAC rates suggesting twin cesarean delivery rate is more closely related to a hospital's general obstetric practice than its twin delivery volume.

Intrapartum obstetric care in the United States military: Comparison of military and civilian care systems within TRICARE

BACKGROUND

Expectant mothers who are beneficiaries of TRICARE (universal insurance to United States Armed Services members and their dependents) can choose to receive care within direct (salary-based) or purchased (fee-for-service) care systems. We sought to compare frequency of intrapartum obstetric procedures and outcomes such as severe acute maternal morbidity (SAMM) and common postpartum complications between direct and purchased care systems within TRICARE.

METHODS

TRICARE (2006-2010) claims data were used to identify deliveries. Patient demographics, frequency of types of delivery (noninstrumental vaginal, cesarean, and instrumental vaginal), comorbid conditions, SAMM, and common postpartum complications were compared between the two systems of care. Multivariable models adjusted for patient clinical/demographic factors determined the odds of common complications and SAMM complications in purchased care compared with direct care.

RESULTS

A total of 440 138 deliveries were identified. Compared with direct care, purchased care had higher frequency (30.9% vs 25.8%, P<.001) and higher adjusted odds (aOR 1.37 [CI 1.34-1.38]) of cesarean delivery. In stratified analysis by mode of delivery, purchased care had lower odds of common complications for all modes of delivery (aOR[CI]:noninstrumental vaginal: 0.72 [0.71-0.74], cesarean: 0.71 [0.68-0.75], instrumental vaginal: 0.64 [0.60-0.68]) than direct care. However, purchased care had higher odds of SAMM complications for cesarean delivery (aOR 1.31 [CI 1.19-1.44]) compared with direct care.

CONCLUSION

Direct care has a higher vaginal delivery rate but also a higher rate of common complications compared with purchased care. Study of direct and purchased care systems in TRICARE may have potential use as a surrogate for comparing obstetric care between salary-based systems and fee-for-service systems in the United States.