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.

Six versus twelve hours of single-balloon catheter placement with oxytocin administration for labor induction: a randomized controlled trial.

BACKGROUND: Induction of labor is common in the United States. Multiple previous studies have tried to outline a faster time to delivery to improve maternal and fetal outcomes. OBJECTIVE: This study aimed to evaluate whether women who undergo induction of labor with a single-balloon catheter and oxytocin have a shorter time to delivery with planned removal of the catheter at 6 vs 12 hours. STUDY DESIGN: In this randomized controlled trial, induction of labor was performed using a combination of single-balloon catheter and oxytocin. Term women, both nulliparous and multiparous, aged 18 to 50 years old with cephalic singletons were included if they were undergoing induction of labor with a Bishop score of <6 and cervical dilation of <2 cm. Women were randomized to planned removal of the single-balloon catheter at 6 hours vs 12 hours. The primary outcome was time from catheter insertion to delivery. We were powered to show a 4-hour time difference with a sample size of 89 women per group (n=178). Planned sensitivity analyses were performed to account for cesarean delivery in labor. RESULTS: From February 2019 to June 2020, 237 women were screened, 178 women were randomized, and 177 women were included in the final analysis (89 women in the 6-hour group and 88 women in the 12-hour group). Insertion to delivery time was significantly shorter in the 6-hour group (19.2 vs 24.3 hours; P=.04), and the proportion of women delivered by 24 hours was significantly greater in the 6-hour group (67.4% vs 47.4%; P<.01). There was no difference in the Bishop score at removal of the catheter or secondary maternal or neonatal outcomes. In a Cox proportional-hazards model censoring for cesarean delivery, the 6-hour group had a significantly shorter insertion to delivery time (hazard ratio, 0.67; P=.02). CONCLUSION: Induction of labor with a single-balloon catheter and oxytocin with planned removal of the catheter at 6 hours rather than 12 hours results in a shorter time from insertion to delivery without increasing the rate of cesarean delivery. Decreasing the length of time a single-balloon catheter is in place should be considered in clinical protocols.

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.

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.

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..

Introduction of a Novel System for Quantitating Blood Loss After Vaginal Delivery: A Retrospective Interrupted Time Series Analysis With Concurrent Control Group.

BACKGROUND: Postpartum hemorrhage (PPH) is a leading cause of maternal mortality worldwide. While volumetric and gravimetric blood loss measurement techniques have been shown to increase PPH detection compared to visual estimation of blood loss (vBL), a combination of these methods has not been evaluated. The primary aim of this study was to compare the change in odds of PPH detection after vaginal delivery (VD; the intervention series) versus cesarean delivery (CD; the control series) before versus after implementation of a device (Triton L&D, Gauss Surgical, Inc, Los Altos, CA) that combines gravimetric and volumetric estimation of blood loss (tBL). METHODS: After institutional review board (IRB) approval, patients were identified who had a VD or CD at our institution 3 months before and 3 months after the implementation of a tBL device for VD. The levels and trends in odds of PPH detection (the primary outcome, defined as blood loss ≥500 mL for VD and ≥1000 mL for CD) were compared within and between delivery methods before and after implementation of the device. Secondary outcomes were blood loss ≥1000 mL, total blood loss, secondary uterotonic use, and a composite outcome related to PPH management (transfusion, vasopressor administration, and/or surgical procedures). A post hoc subgroup analysis compared nadir hematocrit, hematocrit reduction ≥10%, and difference between vBL or tBL and calculated blood loss (cBL) between VDs before and after introduction of the device. All outcome comparisons were performed using segmented regression with inverse probability of treatment weighting. RESULTS: The weighted odds ratio (wOR) of PPH detection post- versus preimplementation of the device was 2.74 (95% confidence interval [CI], 1.39-5.41; P = .004) for VDs versus 1.43 (95% CI, 0.72-2.85; P = .304) for CDs (P for interaction .190). No difference was detected in the secondary outcomes for VDs between time periods. In the subgroup of VD patients who had postdelivery hematocrits measured, the mean difference between vBL or tBL and cBL was smaller in the tBL (mean ± standard deviation [SD]: -237 ± 522 mL) versus vBL group (-600 ± 596 mL; weighted difference in means [95% CI]: 349 mL [13-684]; P = .042). CONCLUSIONS: In this interrupted time series analysis, the odds of PPH detection after VD increased after implementation of the tBL device. However, a statistical difference was not detected between the increase in PPH detection post- versus preimplementation of the device in VDs versus CDs.

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.

Identifying Barriers to Implementation of the National Partnership for Maternal Safety Obstetric Hemorrhage Bundle at a Tertiary Center: Utilization of the Delphi Method.

BACKGROUND: In 2015, the National Partnership for Maternal Safety (NPMS) developed an obstetric hemorrhage consensus bundle to provide birthing facilities in the United States with consistent, validated practice guidelines for postpartum hemorrhage management. The process of implementing each bundle element at a large tertiary labor and delivery unit has not been described; we sought to identify practice deficiencies and perceived barriers to bundle implementation among multidisciplinary providers. METHODS: We conducted a prospective, cross-sectional, consensus-building study based on the Delphi method. A multidisciplinary expert panel comprised of anesthesiologists, obstetricians, nurses, and surgical technicians was assembled and participated in 4 sequential questionnaires. The first round identified bundle elements that experts determined as not currently adequate and perceived barriers to implementation. The second round established prioritization of elements within each professional group; and the third round ranked the elements with at least 60% agreement on feasibility of implementation and positive impact on patient care. The last round revealed responses across all 4 professional groups to derive a final consensus. Descriptive statistics were performed. RESULTS: A total of 38 experts completed the study (11 anesthesiologists, 11 obstetricians, 10 nurses, and 6 surgical technicians). While all 13 (100%) NPMS obstetric bundle elements were described as deficient in our labor and delivery unit by a provider in at least 1 discipline, consensus among at least 3 of the 4 disciplines was achieved for 6 element deficiencies. Barriers to implementation were determined. The initiatives that achieved consensus as possessing high patient impact and implementation feasibility were protocol-driven management, unit-based simulation drills, blood loss quantification, and team huddles and debriefings. CONCLUSIONS: The NPMS obstetric hemorrhage bundle was created to help guide practice and systems improvement for US birthing facilities. The Delphi method enabled identification of deficient elements and perceived barriers to element implementation, as well as group consensus on elements with highest patient impact and feasibility. Multidisciplinary group consensus can identify deficiencies and promote tangible, quality improvements in a large, tertiary-care labor and delivery unit. Institutions may utilize our described technique to guide implementation of future care bundles.

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.

Peripartum Care for Mothers Diagnosed with Hepatitis B During Pregnancy: A Survey of Provider Practices.

Objectives Hepatitis B (HBV) remains a significant public health burden, despite effective therapy. Routine HBV screening is recommended during pregnancy to reduce the risk of vertical transmission, but the rates of follow-up care peri-partum are low. The aim of this study was to evaluate physician practices and knowledge regarding HBV in women diagnosed perinatally. Methods A survey was distributed to obstetricians and midwives within the Partners HealthCare system at Brigham and Women's Hospital and Massachusetts General Hospital. Results Of 118 survey respondents (response rate 56%), 97% reported that they always tested for hepatitis B, and 77% referred new diagnoses of HBV during pregnancy to a HBV specialist for further care. Only 10% of respondents reported that there was formal referral mechanism in place to facilitate follow-up care for mothers diagnosed with hepatitis B infection. 91% of survey respondents selected hepatitis B surface antigen as the correct screening test, and 76% selected hepatitis B immune globulin with vaccination for the newborn as the correct prophylaxis regimen. Only 40 and 51% of respondents accurately identified serologies that were consistent with acute and chronic infection, respectively. Conclusions for Practice Routine screening for HBV in this population presents an important opportunity to identify cases and to reduce the public health burden of this disease. Providers were somewhat knowledgeable about HBV, but the lack of formal referral mechanism may explain why HBV follow-up is suboptimal in this healthcare system. Supplemental provider education and formal linkage to care programs may increase rates of follow-up HBV care.

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.

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.

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.

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.

Spatiotemporal alignment of in utero BOLD-MRI series.

PURPOSE: To present a method for spatiotemporal alignment of in-utero magnetic resonance imaging (MRI) time series acquired during maternal hyperoxia for enabling improved quantitative tracking of blood oxygen level-dependent (BOLD) signal changes that characterize oxygen transport through the placenta to fetal organs. MATERIALS AND METHODS: The proposed pipeline for spatiotemporal alignment of images acquired with a single-shot gradient echo echo-planar imaging includes 1) signal nonuniformity correction, 2) intravolume motion correction based on nonrigid registration, 3) correction of motion and nonrigid deformations across volumes, and 4) detection of the outlier volumes to be discarded from subsequent analysis. BOLD MRI time series collected from 10 pregnant women during 3T scans were analyzed using this pipeline. To assess pipeline performance, signal fluctuations between consecutive timepoints were examined. In addition, volume overlap and distance between manual region of interest (ROI) delineations in a subset of frames and the delineations obtained through propagation of the ROIs from the reference frame were used to quantify alignment accuracy. A previously demonstrated rigid registration approach was used for comparison. RESULTS: The proposed pipeline improved anatomical alignment of placenta and fetal organs over the state-of-the-art rigid motion correction methods. In particular, unexpected temporal signal fluctuations during the first normoxia period were significantly decreased (P < 0.01) and volume overlap and distance between region boundaries measures were significantly improved (P < 0.01). CONCLUSION: The proposed approach to align MRI time series enables more accurate quantitative studies of placental function by improving spatiotemporal alignment across placenta and fetal organs. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:403-412.

Twin vaginal delivery: innovate or abdicate.

Neonatal safety data along with national guidelines have prompted renewed interest in vaginal delivery of twins, particularly in the case of the noncephalic second twin. Yet, the rising rate of twin cesarean deliveries, coupled with the national decline in operative obstetrics, raises concerns about the availability of providers who are skilled in twin vaginal birth. Providers are key stakeholders for increasing rates of twin vaginal delivery. We surveyed a group of practicing obstetricians to explore potential barriers to the vaginal birth of twins with a focus on delivery of the noncephalic second twin. Among 107 responding providers, only 57% would deliver a noncephalic second twin by breech extraction. Providers who preferred breech extraction had a higher rate of maternal-fetal medicine subspecialty training (26.2% vs 4.3%; P<.01) and were more likely to be in an academic practice environment (36.1% vs 10.9%; P<.01) and to practice in high-volume centers that deliver >30 sets of twins annually (57.4% vs 34.8%; P=.02). Most providers (54.2%) were familiar with the findings from the recent randomized trial that demonstrated the safety of twin vaginal birth. However, knowledge of the trial was not associated statistically with a preference for breech extraction (62.3% vs 43.5%; P=.05). Providers who preferred breech extraction were more likely to agree with recent society guidelines that encourage the vaginal birth of twins (86.9% vs 63.0%; P<.01). In an adjusted analysis, the 46% of providers with a perceived need for more training were far less likely to prefer breech extraction for delivery of a noncephalic second twin (adjusted odds ratio, 0.38; 95% confidence interval, 0.16-0.95). Furthermore, 57% of providers who would not offer their patient breech extraction would be willing to consult a colleague for support with a noncephalic twin delivery. These results suggest that scientific evidence and society opinion are likely insufficient to reverse the national trends that favor cesarean delivery for twins. Instead, implementation of provider training and support programs is critical for increasing the rates of twin vaginal birth. Changing our national landscape of vaginal twin delivery may require innovation. Without novel provider-focused strategies, we may relinquish passively the requisite skills for not only our patients but also for future generations of obstetricians.

Dural Puncture Epidural Technique Improves Labor Analgesia Quality With Fewer Side Effects Compared With Epidural and Combined Spinal Epidural Techniques: A Randomized Clinical Trial.

BACKGROUND: The dural puncture epidural (DPE) technique is a modification of the combined spinal epidural (CSE) technique, where a dural perforation is created from a spinal needle but intrathecal medication administration is withheld. The DPE technique has been shown to improve caudal spread of analgesia compared with epidural (EPL) technique without the side effects observed with the CSE technique. We hypothesized that the onset of labor analgesia would follow this order: CSE > DPE > EPL techniques. METHODS: A total of 120 parturients in early labor were randomly assigned to EPL, DPE, or CSE groups. Initial dosing for EPL and DPE consisted of epidural 20 mL of 0.125% bupivacaine plus fentanyl 2 µg/mL over 5 minutes, and for CSE, intrathecal 0.25% bupivacaine 1.7 mg and fentanyl 17 µg. Upon block completion, a blinded coinvestigator assessed the outcomes. Two blinded obstetricians retrospectively interpreted uterine contractions and fetal heart rate tracings 1 hour before and after the neuraxial technique. The primary outcome was time to numeric pain rating scale (NPRS) ≤ 1 analyzed by using Kaplan-Meier curves and Cox proportional hazard model. Secondary outcomes included block quality, maternal adverse effects, uterine contraction patterns, and fetal outcomes analyzed by using the χ test with Yates continuity correction. RESULTS: There was no significant difference in the time to NPRS ≤ 1 between DPE and EPL (hazard ratio 1.4; 95% confidence interval [CI] 0.83-2.4, P = .21). DPE achieved NPRS ≤ 1 significantly slower than CSE (hazard ratio 0.36; 95% CI 0.22-0.59, P = .0001). The median times (interquartile range) to NPRS ≤ 1 were 2 (0.5-6) minutes for CSE, 11 (4-120) minutes for DPE, and 18 (10-120) minutes for EPL. Compared with EPL, DPE had significantly greater incidence of bilateral S2 blockade at 10 minutes (risk ratio [RR] 2.13; 95% CI 1.39-3.28; P < .001), 20 minutes (RR 1.60; 95% CI 1.26-2.03; P < .001), and 30 minutes (RR 1.18; 95% CI 1.01-1.30; P < .034), a lower incidence of asymmetric block after 30 minutes (RR 0.19; 95% CI 0.07-0.51; P < .001) and physician top-up intervention (RR 0.45; 95% CI 0.23-0.86; P = .011). Compared with CSE, DPE had a significantly lower incidence of pruritus (RR 0.15; 95% CI 0.06-0.38; P < .001), hypotension (RR 0.38; 95% CI 0.15-0.98; P = .032), combined uterine tachysystole and hypertonus (RR 0.22; 95% CI 0.08-0.60; P < .001), and physician top-up intervention (RR 0.45; 95% CI 0.23-0.86; p = .011). CONCLUSIONS: Analgesia onset was most rapid with CSE with no difference between DPE and EPL techniques. The DPE technique has improved block quality over the EPL technique with fewer maternal and fetal side effects than the CSE technique for parturients requesting early labor analgesia.

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.

Does Universal Insurance Mitigate Racial Differences in Minimally Invasive Hysterectomy?

STUDY OBJECTIVE: To determine if racial differences exist in receipt of minimally invasive hysterectomy (defined as total vaginal hysterectomy [TVH] and total laparoscopic hysterectomy [TLH]) compared with an open approach (total abdominal hysterectomy [TAH]) within a universally insured patient population. DESIGN: Retrospective data analysis (Canadian Task Force classification II-2). SETTING: The 2006-2010 national TRICARE (universal insurance coverage to US Armed Services members and their dependents) longitudinal claims data. PATIENTS: Women aged 18 years and above who underwent hysterectomy stratified into 4 racial groups: white, African American, Asian, and "other." INTERVENTION: Receipt of hysterectomy (TAH, TVH, or TLH). MEASUREMENTS AND MAIN RESULTS: We used risk-adjusted multinomial logistic regression models to determine the relative risk ratios of receipt of TVH and TLH compared with TAH in each racial group compared with referent category of white patients for benign conditions. Among 33 015 patients identified, 60.82% (n = 20 079) were white, 26.11% (n = 8621) African American, 4.63% (n = 1529) Asian, and 8.44% (n = 2786) other. Most hysterectomies (83.9%) were for benign indications. Nearly 42% of hysterectomies (n = 13 917) were TAH, 27% (n = 8937) were TVH, and 30% (n = 10 161) were TLH. Overall, 36.37% of white patients received TAH compared with 53.40% of African American patients and 51.01% of Asian patients (p < .001). On multinomial logistic regression analyses, African American patients were significantly less likely than white patients to receive TVH (relative risk ratio [RRR], .63; 95% confidence interval [CI], .58-.69) or TLH (RRR, .65; 95% CI, .60-.71) compared with TAH. Similarly, Asian patients were less likely than white patients to receive TVH (RRR, .71; 95% CI, .60-.84) or TLH (RRR, .69; 95% CI, .58-.83) compared with TAH. Analyses by benign indications for surgery showed similar trends. CONCLUSION: We demonstrate that racial minority patients are less likely to receive a minimally invasive surgical approach compared with an open abdominal approach despite universal insurance coverage. Further work is warranted to better understand factors other than insurance access that may contribute to racial differences in surgical approach to hysterectomies.