Delivery For Nonreassuring Fetal Status Research Articles

Intrapartum electronic fetal monitoring features associated with a clinical diagnosis of nonreassuring fetal status

Nonreassuring fetal status detected by continuous electronic fetal monitoring accounts for almost 1 in 4 primary cesarean deliveries. However, given the subjective nature of the diagnosis, there is a need to identify the electronic fetal monitoring patterns that are clinically considered nonreassuring. This study aimed to describe which electronic fetal monitoring features are most commonly associated with first-stage cesarean delivery for nonreassuring fetal status, and to evaluate the risk of neonatal acidemia following cesarean delivery for nonreassuring fetal status. This was a nested case-control study in a prospectively collected cohort of patients with singleton pregnancies at ≥37 weeks' gestation, admitted in spontaneous labor or for induction of labor from 2010 to 2014 at a single tertiary care center. Patients with preterm pregnancies, multiple gestations, planned cesarean delivery, or nonreassuring fetal status in the second stage of labor were excluded. Cases were identified as having nonreassuring fetal status on the basis of what was documented in the operative note by the delivering physician. Controls were patients without nonreassuring fetal status within 1 hour of delivery. Cases were matched to controls in a 1:2 ratio by parity, obesity, and history of cesarean delivery. Electronic fetal monitoring data were abstracted by credentialed obstetrical research nurses for the 60 minutes before delivery. The primary exposure of interest was the incidence of high-risk category II electronic fetal monitoring features in the 60 minutes before delivery; in particular, the incidence of minimal variability, recurrent late decelerations, recurrent variable decelerations, tachycardia, and >1 prolonged deceleration were compared between groups. We also compared neonatal outcomes between cases and controls, including fetal acidemia (umbilical artery pH <7.1), other umbilical artery gas analytes, and neonatal and maternal outcomes. Of the 8580 patients in the parent study, 714 (8.3%) underwent cesarean delivery for nonreassuring fetal status in the first stage of labor. Patients diagnosed with nonreassuring fetal status requiring cesarean delivery were more likely to have recurrent late decelerations, >1 prolonged deceleration, and recurrent variable decelerations compared with controls. More than 1 prolonged deceleration was associated with 6 times increased rate of nonreassuring fetal status diagnosis resulting in cesarean delivery (adjusted odds ratio, 6.73 [95% confidence interval, 2.47-8.33]). Rates of fetal tachycardia were similar between groups. Minimal variability was less common in the nonreassuring fetal status group compared with controls (adjusted odds ratio, 0.36 [95% confidence interval, 0.25-0.54]). Compared with control deliveries, cesarean delivery for nonreassuring fetal status was associated with nearly 7 times higher risk of neonatal acidemia (7.2% vs 1.1%; adjusted odds ratio, 6.93 [95% confidence interval, 3.83-12.54]). Composite neonatal morbidity and composite maternal morbidity were more likely among patients delivered for nonreassuring fetal status in the first stage (3.9% vs 1.1%; adjusted odds ratio, 5.70 [2.60-12.49]; and 13.3% vs 8.0%; adjusted odds ratio, 1.99 [1.41-2.80]). Although multiple category II electronic fetal monitoring features have been traditionally linked to acidemia, the presence of recurrent late decelerations, recurrent variable decelerations, and prolonged decelerations seemed to concern obstetricians enough to surgically intervene for nonreassuring fetal status. A clinical intrapartum diagnosis of nonreassuring fetal status in the setting of these electronic fetal monitoring features is also associated with increased risk of acidemia, suggesting clinical validity to the diagnosis of nonreassuring fetal status.

Establishment method and significance of birthweight curve and reference in single center

Objective: To establish neonatal birthweight percentile curves based on single-center cohort database using different methods, compare them with the current national birthweight curves and discuss the appropriateness and significance of single-center birthweight standard. Methods: Based on a prospective first-trimester screening cohort at Nanjing Drum Tower Hospital from January 2017 to February 2022, the generalized additive models for location, scale and shape (GAMLSS) and semi-customized method were applied to generate local birthweight percentile curves (hereinafter referred to as the local GAMLSS curves, semi-customized curves) for 3 894 cases who were at low risk of small for gestation age (SGA) and large for gestation age (LGA). Infants were categorized as SGA (birth weight<10th centile) by both semi-customized and local GAMLSS curves, semi-customized curves only, or not SGA (met neither criteria). The incidence of adverse perinatal outcome between different groups was compared. The same method was used to compare the semi-customized curves with the Chinese national birthweight curves (established by GAMLSS method as well, hereinafter referred to as the national GAMLSS curves). Results: (1) Among the 7 044 live births, 404 (5.74%, 404/7 044), 774 (10.99%, 774/7 044) and 868 (12.32%, 868/7 044) cases were diagnosed as SGA according to the national GAMLSS curves, the local GAMLSS curves and the semi-customized curves respectively. The birth weight of the 10th percentile of the semi-customized curves was higher than that of the local GAMLSS curves and the national GAMLSS curves at all gestational age. (2) When comparing semi-customized curves and the local GAMLSS curves, the incidence of admission to neonatal intensive care unit (NICU) for more than 24 hours of infants identified as SGA by semi-customized curves only (94 cases) and both semi-customized and local GAMLSS curves (774 cases) was 10.64% (10/94) and 5.68% (44/774) respectively, both significantly higher than that in non SGA group [6 176 cases, 1.34% (83/6 176); P<0.001]. The incidence of preeclampsia, pregnancy<34 weeks, and pregnancy<37 weeks of infants identified as SGA by the semi-customized curves only and both semi-customized and local GAMLSS curves was 12.77% (12/94) and 9.43% (73/774), 9.57% (9/94) and 2.71% (21/774), 24.47% (23/94) and 7.24% (56/774) respectively, which were significantly higher than those of the non SGA group [4.37% (270/6 176), 0.83% (51/6 176), 4.23% (261/6 176); all P<0.001]. (3) When comparing semi-customized curves and the national GAMLSS curves, the incidence of admission to NICU for more than 24 hours of infants identified as SGA by semi-customized curves only (464 cases) and both semi-customized and national GAMLSS curves (404 cases) was 5.60% (26/464) and 6.93% (28/404) respectively, both significantly higher than that in non SGA group [6 176 cases, 1.34% (83/6 176); all P<0.001]. The incidence of emergency cesarean section or forceps delivery for non-reassuring fetal status (NRFS) in infants identified as SGA by semi-customized curves only and both semi-customized and national GAMLSS curves was 4.96% (23/464) and 12.38% (50/404), both significantly higher than that in the non SGA group [2.57% (159/6 176); all P<0.001]. The incidence of preeclampsia, pregnancy<34 weeks, and pregnancy<37 weeks in the semi-customized curves only group and both semi-customized and national GAMLSS curves group was 8.84% (41/464) and 10.89% (44/404), 4.31% (20/464) and 2.48% (10/404), 10.56% (49/464) and 7.43% (30/404) respectively, all significantly higher than those in the non SGA group [4.37% (270/6 176), 0.83% (51/6 176), 4.23% (261/6 176); all P<0.001]. Conclusion: Compared with the national GAMLSS birthweight curves and the local GAMLSS curves, the birth weight curves established by semi-customized method based on our single center database is in line with our center' SGA screening, which is helpful to identify and strengthen the management of high-risk infants.

Cesarean Delivery Trends Among Patients at Low Risk for Cesarean Delivery in the US, 2000-2019

Reducing rates of unnecessary cesarean deliveries is both a national and a global health objective. However, there are limited national US data on trends in indications for low-risk cesarean delivery. To determine temporal trends in and indications for cesarean delivery among patients at low risk for the procedure over a 20-year period. This cross-sectional study analyzed 2000 to 2019 delivery hospitalizations using the National Inpatient Sample. Births at low risk for cesarean delivery were identified using a definition from the Society for Maternal-Fetal Medicine and additional criteria. Temporal trends in cesarean birth were analyzed using joinpoint regression to estimate the average annual percentage change (AAPC) with 95% CIs. Data analysis was performed from August 2022 to January 2023. This analysis evaluated cesarean birth trends in a population at low risk for this procedure over a 20-year period. In addition to overall cesarean birth risk, cesarean deliveries for nonreassuring fetal status and labor arrest were individually analyzed. Of an estimated 76.7 million delivery hospitalizations, 21.5 million were excluded according to the Society for Maternal-Fetal Medicine definition, and 14.7 million were excluded according to additional criteria. Of the estimated 40 517 867 deliveries included, 12.1% (4 885 716 deliveries) were by cesarean delivery. Cesarean deliveries among patients at low risk for the procedure increased from 9.7% to 13.9% between 2000 and 2009, plateaued, and then decreased from 13.0% to 11.1% between 2012 and 2019. The AAPC for cesarean delivery was 6.4% (95% CI, 5.2% to 7.6%) from 2000 to 2005, 1.2% from 2005 to 2009 (95% CI, -1.2% to 3.7%), and -2.2% from 2009 to 2019 (95% CI, -2.7% to -1.8%). Cesarean delivery for nonreassuring fetal status increased from 3.4% of all deliveries in 2000 to 5.1% in 2019 (AAPC, 2.1%; 95% CI, 1.7% to 2.5%). Cesarean delivery for labor arrest increased from 3.6% in 2000 to a peak of 4.8% in 2009 before decreasing to 2.7% in 2019. Cesarean deliveries for labor arrest increased during the first half of the study (2000-2009) for the active phase (from 1.5% to 2.1%), latent phase (from 1.1% to 1.5%), and second stage (from 0.9% to 1.3%) and then decreased from 2010 to 2019, from 2.1% to 1.7% for the active phase, from 1.5% to 1.2% for the latent phase, and from 1.2% to 0.9% for the second stage. Cesarean deliveries among patients at low risk for cesarean birth appeared to decrease over the latter years of the study period, with cesarean deliveries for labor arrest becoming less common.

Routine Ultrasound at 30th–33rd weeks versus 30th–33rd and 35th–37th weeks in Low-Risk Pregnancies: A Randomized Trial

Introduction: The aim of this study was to evaluate the accuracy of 35–37 weeks’ ultrasound for fetal growth restriction (FGR) detection and the impact of 30th–33rd weeks versus 30th–33rd and 35th–37th weeks’ ultrasound on perinatal outcomes. Methods: This was a randomized controlled trial that enrolled 1,061 low-risk pregnant women: 513 in the control group (routine ultrasound performed at 30th–33rd weeks) and 548 in the study group (with an additional ultrasound at 35th–37th weeks). FGR was defined as a fetus with an estimated fetal weight (EFW) below the 10th percentile. p values < 0.05 were considered statistically significant. Results: The ultrasound at 35–37 weeks had an overall accuracy of FGR screening of 94%. Spearman’s correlation coefficient between EFW and birthweight centile was higher for at 35–37 weeks’ ultrasound (ρ = 0.75) compared with 30–33 weeks’ ultrasound (ρ = 0.44). The study group had a lower rate of operative vaginal deliveries (24.4% vs. 39.3%, p = 0.005) and cesarean deliveries for nonreassuring fetal status (16.8% vs. 38.8%, p < 0.001). Discussion/Conclusion: A later ultrasound (35–37 weeks) had a high accuracy for detection of FGR and had a higher correlation between EFW and birthweight centiles. Furthermore, it was also associated with lower adverse perinatal outcomes compared to an earlier ultrasound.

The magnitude rather than the rate of decline in fetal growth is a stronger risk factor for perinatal mortality in term infants

Prenatal diagnosis of an infant suspected of having fetal growth restriction is important because of its strong association with perinatal mortality and morbidity. The current Delphi consensus criteria include a decline of >50th percentiles in fetal growth when diagnosing late fetal growth restriction; however, the evidence underpinning this criterion is limited. This study aimed to analyze the relationships among the magnitude of decline in fetal growth and stillbirth, perinatal mortality, and adverse neonatal outcomes. This cohort study of 15,861 pregnancies was conducted at the Mater Mother's Hospital in Brisbane, Australia. The decline in fetal growth was calculated as a drop in either estimated fetal weight or abdominal circumference percentiles between 2 ultrasound scans performed after 18 weeks of gestation. Relationships between declining fetal growth and the outcomes were, firstly, analyzed as a continuous variable and, if significant, further assessed with the rate of decline and different magnitudes of decline, compared to the referent category (change in growth of ±10 percentiles between scans). The 3 categories of growth decline were >10th to <25th percentiles, ≤25th to <50th percentiles, and ≥50th percentiles. Associations were analyzed by logistic regressions. The primary study outcomes were stillbirth and perinatal mortality (composite of stillbirth and neonatal death). The secondary outcomes were birth of a small-for-gestational-age infant (birthweight of <10th percentile for gestation), emergency cesarean delivery for nonreassuring fetal status, and composite severe neonatal morbidity. The risks of stillbirth and perinatal mortality increased significantly by 2.6% (0.4%-4.6%) and 2.8% (1.0%-4.5%), respectively, per 1 percentile decline in fetal growth. In addition, the odds of stillbirth (adjusted odds ratio, 3.68 (1.32-10.24) and perinatal mortality (4.44) (1.82-10.84)) compared to the referent group were significantly increased only when the decline was ≥50th percentiles, regardless of birthweight. Furthermore, none of the primary outcomes were significantly associated with the rate of growth decline. The risk of a small-for-gestational-age infant increased by 2.4% (2.2%-2.7%) for every percentile decline. Conversely, reduced fetal growth was not associated with emergency cesarean delivery for nonreassuring fetal status or severe neonatal morbidity. Our results supported the use of a ≥50th percentile decline in fetal growth as a criterion for identifying infants at risk of late fetal growth restriction. This cutoff also identified fetuses at high risk of perinatal mortality, regardless of birthweight and rate of growth decline. Our findings may guide obstetrical practice by alerting clinicians to the importance of incorporating the magnitude of fetal growth decline into antenatal counseling and decisions regarding the timing of birth.

Perinatal Adverse Effects in Newborns with Estimated Loss of Weight Percentile between the Third Trimester Ultrasound and Delivery. The GROWIN Study.

Fetal growth restriction has been associated with an increased risk of adverse perinatal outcomes (APOs). We determined the importance of fetal growth detention (FGD) in late gestation for the occurrence of APOs in small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) newborns. For this purpose, we analyzed a retrospective cohort study of 1067 singleton pregnancies. The newborns with higher APOs were SGA non-FGD and SGA FGD in 40.9% and 31.5% of cases, respectively, and we found an association between SGA non-FGD and any APO (OR 2.61; 95% CI: 1.35–4.99; p = 0.004). We did not find an increased APO risk in AGA FGD newborns (OR: 1.13, 95% CI: 0.80, 1.59; p = 0.483), except for cesarean delivery for non-reassuring fetal status (NRFS) with a decrease in percentile cutoff greater than 40 (RR: 2.41, 95% CI: 1.11–5.21) and 50 (RR: 2.93, 95% CI: 1.14–7.54). Conclusions: Newborns with the highest probability of APOs are SGA non-FGDs. AGA FGD newborns do not have a higher incidence of APOs than AGA non-FGDs, although with falls in percentile cutoff over 40, they have an increased risk of cesarean section due to NRFS. Further studies are warranted to detect these newborns who would benefit from close surveillance in late gestation and at delivery.

Intrapartum Resuscitation Interventions for Category II Fetal Heart Rate Tracings and Improvement to Category I.

To evaluate intrapartum resuscitation interventions and improvement in category II fetal heart rate (FHR) tracings. This secondary analysis of a randomized trial of intrapartum fetal electrocardiographic ST-segment analysis included all participants with category II FHR tracings undergoing intrauterine resuscitation: maternal oxygen, intravenous fluid bolus, amnioinfusion, or tocolytic administration. Fetal heart rate pattern-recognition software was used to confirm category II FHR tracings 30 minutes before intervention and to analyze the subsequent 60 minutes. The primary outcome was improvement to category I within 60 minutes. Secondary outcomes included FHR tracing improvement to category I 30-60 minutes after the intervention and composite neonatal outcome. Of 11,108 randomized participants, 2,251 (20.3%) had at least one qualifying intervention for category II FHR tracings: 63.7% improved to category I within 60 minutes and 50.5% improved at 30-60 minutes. Only 3.4% underwent cesarean delivery and 4.1% an operative vaginal delivery for nonreassuring fetal status within 60 minutes after the intervention. Oxygen administration was the most common intervention (75.4%). Among American College of Obstetricians and Gynecologists-defined subgroups that received oxygen, the absent FHR accelerations and absent-minimal FHR variability subgroup (n=332) was more likely to convert to category I within 60 minutes than the FHR accelerations or "moderate FHR variability" subgroup (n=1,919) (77.0% vs 63.0%, odds ratio [OR] 2.0, 95% CI 1.4-2.7). The incidence of composite neonatal adverse outcome for category II tracings was 2.9% (95% CI 2.2-3.7%) overall; 2.8% (95% CI 2.0-3.8%) for improvement to category I within 60 minutes (n=1,433); and 3.2% (95% CI 2.1-4.6%) for no improvement within 60 minutes (n=818). However, the group with improvement had 29% lower odds for higher level neonatal care (11.8% vs 15.9%, OR 0.71, 95% CI 0.55-0.91). Nearly two thirds of category II FHR tracings improved to category I within 60 minutes of intervention with a relatively low overall rate of the composite neonatal adverse outcome. Funded in part by Neoventa Medical.

Obstetric Outcomes in Singleton Pregnancies with Abnormal Placental Cord Insertions.

There is wide variation in the management of pregnancies complicated by abnormal placental cord insertion (PCI), which includes velamentous cord insertion (VCI) and marginal cord insertion (MCI). We tested the hypothesis that abnormal PCI is associated with small for gestational age (SGA) infants. This is a retrospective cohort study of all pregnant patients undergoing anatomic ultrasound at a single institution from 2010 to 2017. Patients with abnormal PCI were matched in a 1:2 ratio by race, parity, gestational age at the time of ultrasound, and obesity to patients with normal PCIs. The primary outcome was SGA at delivery. Secondary outcomes were cesarean delivery, preterm delivery, cesarean delivery for nonreassuring fetal status, 5-minute Apgar score < 7, umbilical artery pH < 7.1, and neonatal intensive care unit admission. These outcomes were compared using univariate and bivariate analyses. Abnormal PCI was associated with an increased risk of SGA (relative risk [RR]: 2.43; 95% confidence interval [CI]: 1.26-4.69), increased risk of preterm delivery <37 weeks (RR: 3.60; 95% CI: 1.74-7.46), and <34 weeks (RR: 3.50; 95% CI: 1.05-11.63) compared with patients with normal PCI. There was no difference in rates of cesarean delivery, Apgar score of <7 at 5 minutes, acidemia, or neonatal intensive care unit admission between normal and abnormal PCI groups. In a stratified analysis, the association between abnormal PCI and SGA did not differ by the type of abnormal PCI (p for interaction = 0.46). Abnormal PCI is associated with an increased risk of SGA and preterm delivery. These results suggest that serial fetal growth assessments in this population may be warranted. · Abnormal PCI is associated with SGA infants and preterm birth.. · If an abnormal PCI is identified, the provider should consider serial growth ultrasounds.. · There is no difference in obstetric outcomes between VCI and MCI..

Timing of delivery with coronavirus disease 2019 pneumonia requiring intensive care unit admission

Approximately 4% of pregnant patients with coronavirus disease 2019 require intensive care unit admission. Given the practical implications of advanced ventilatory and circulatory support techniques, urgent or emergent delivery for nonreassuring fetal status frequently presents a logistical impossibility. This article proposes a protocol for obstetrical management of patients in these situations, emphasizing coordinated preparation among obstetrical, anesthesiology, and intensivist teams for planned preterm delivery at gestational ages when neonatal outcomes are likely to be favorable.

Maternal and neonatal outcomes of pregnancies complicated by late fetal growth restriction undergoing induction of labor with dinoprostone compared with cervical balloon: A retrospective, international study.

The aim of this study was to compare vaginal dinoprostone and mechanical methods for induction of labor (IOL) in pregnancies complicated by late fetal growth restriction. Multicenter, retrospective, cohort study involving six referral centers in Italy and Spain. Inclusion criteria were pregnancies complicated by late fetal growth restriction as defined by Delphi consensus criteria. The primary outcome was the occurrence of uterine tachysystole; secondary outcomes were either cesarean delivery or operative vaginal delivery for non-reassuring fetal status, a composite score of adverse neonatal outcome and admission to neonatal intensive care unit (NICU). Univariate and multivariate logistic regression analysis was used to analyze the data. A total of 571 pregnancies complicated by late fetal growth restriction undergoing IOL (391 with dinoprostone and 180 with mechanical methods) were included in the analysis. The incidence of uterine tachysystole (19.2% vs. 5.6%; p=0.001) was higher in women undergoing IOL with dinoprostone than in those undergoing IOL with mechanical methods. Similarly, the incidence of cesarean delivery or operative delivery for non-reassuring fetal status (25.6% vs. 17.2%; p=0.027), composite adverse neonatal outcome (26.1% vs. 16.7%; p=0.013) and NICU admission (16.9% vs. 5.6%; p<0.001) was higher in women undergoing IOL with dinoprostone than in those undergoing IOL with mechanical methods. At logistic regression analysis, IOL with mechanical methods was associated with a significantly lower risk of uterine tachysystole (odds ratio 0.26, 95% confidence interval 0.13-0.54; p<0.001). In pregnancies complicated by late fetal growth restriction, IOL with mechanical methods is associated with a lower risk of uterine tachysystole, cesarean delivery or operative delivery for non-reassuring fetal status, and adverse neonatal outcome compared with pharmacological methods.

Cervical ripening in prolonged pregnancies by silicone double balloon catheter versus vaginal dinoprostone slow release system: The MAGPOP randomised controlled trial.

Prolonged pregnancies are a frequent indication for induction of labour. When the cervix is unfavourable, cervical ripening before oxytocin administration is recommended to increase the likelihood of vaginal delivery, but no particular method is currently recommended for cervical ripening of prolonged pregnancies. This trial evaluates whether the use of mechanical cervical ripening with a silicone double balloon catheter for induction of labour in prolonged pregnancies reduces the cesarean section rate for nonreassuring fetal status compared with pharmacological cervical ripening by a vaginal pessary for the slow release of dinoprostone (prostaglandin E2). This is a multicentre, superiority, open-label, parallel-group, randomised controlled trial conducted in 15 French maternity units. Women with singleton pregnancies, a vertex presentation, ≥41+0 and ≤42+0 weeks' gestation, a Bishop score <6, intact membranes, and no history of cesarean delivery for whom induction of labour was decided were randomised to either mechanical cervical ripening with a Cook Cervical Ripening Balloon or pharmacological cervical ripening by a Propess vaginal pessary serving as a prostaglandin E2 slow-release system. The primary outcome was the rate of cesarean for nonreassuring fetal status, with an independent endpoint adjudication committee determining whether the fetal heart rate was nonreassuring. Secondary outcomes included delivery (time from cervical ripening to delivery, number of patients requiring analgesics), maternal and neonatal outcomes. Between January 2017 and December 2018, 1,220 women were randomised in a 1:1 ratio, 610 allocated to a silicone double balloon catheter, and 610 to the Propess vaginal pessary for the slow release of dinoprostone. The mean age of women was 31 years old, and 80% of them were of white ethnicity. The cesarean rates for nonreassuring fetal status were 5.8% (35/607) in the mechanical ripening group and 5.3% (32/609) in the pharmacological ripening group (proportion difference: 0.5%; 95% confidence interval (CI) -2.1% to 3.1%, p = 0.70). Time from cervical ripening to delivery was shorter in the pharmacological ripening group (23 hours versus 32 hours, median difference 6.5 95% CI 5.0 to 7.9, p < 0.001), and fewer women required analgesics in the mechanical ripening group (27.5% versus 35.4%, difference in proportion -7.9%, 95% CI -13.2% to -2.7%, p = 0.003). There were no statistically significant differences between the 2 groups for other delivery, maternal, and neonatal outcomes. A limitation was a low observed rate of cesarean section. In this study, we observed no difference in the rates of cesarean deliveries for nonreassuring fetal status between mechanical ripening with a silicone double balloon catheter and pharmacological cervical ripening with a pessary for the slow release of dinoprostone. ClinicalTrials.gov NCT02907060.

738 Sex-specific differences in electronic fetal monitoring patterns

Fetal male sex is associated with worse neonatal outcomes, but etiology of this phenomenon is not well elucidated. It has been hypothesized that males have an increased cytokine response and decreased catecholamine response to traumatic events, which could suggest a decreased tolerance of labor and therefore be detected in electronic fetal monitoring (EFM) patterns. We sought to determine if there were differences in EFM features in the 60 minutes prior to delivery. We performed a secondary analysis of a prospective cohort study of low risk women (excluding those with hypertensive disorder or diabetes) with a singleton fetus admitted for labor at term between 2010 to 2014 in a single institution. Baseline characteristics were compared between mothers of male and female infants. The primary outcome was EFM characteristics in the 60 minutes before delivery. Multivariable logistic regression was performed to determine the relationship between fetal sex and EFM characteristic while adjusting for confounders. Of the 4,055 low risk patients, 2,074 (51%) delivered a male infant. Mothers of male fetuses were more likely to go into spontaneous labor (p=0.02), but rates of operative vaginal (5.6 vs 4.1%, p=0.04) and cesarean delivery (CD) (18.1 vs 14.0%, p<0.01) and non-reassuring fetal status as indication for delivery (18.1vs 14.0%, p<0.01) were higher among males. Males were more likely to have bradycardia, recurrent variable decelerations, and higher total deceleration area and were less likely to have tachycardia compared to females. Males had higher odds of decelerations and bradycardia, but females had higher odds of tachycardia, possibly due to improved ability to generate a catecholamine response. Cesarean deliveries for non-reassuring fetal status are more common in pregnancies with male fetuses. These data suggest males are less likely to tolerate stresses of labor, which may drive the difference in mode of delivery and at least partially explain the increased morbidity male neonates experience.

Changes in the Frequency of Cesarean Delivery in Nulliparous Women in Labor in a Canadian Population, 1992-2018.

To examine the relative contribution of changes in patient demographics and physician management to changes in the cesarean delivery rate in labor among nulliparous women. We conducted a retrospective cohort study of 485,451 births to nulliparous women who experienced labor at or beyond 35 weeks of gestation in Alberta, Canada, from 1992 to 2018. The data were from a province-wide perinatal database. The primary outcome was cesarean delivery. Multivariate logistic regression and calculation of population attributable risk for identified risk factors were performed. The cesarean delivery rate increased from 12.5% in 1992 to 24% in 2018. The prevalence of maternal risk factors for cesarean delivery such as obesity, maternal age 35 years or older at delivery, and comorbidities increased over the study period. However, this did not account for the increase in cesarean delivery, because the frequency of cesarean delivery increased irrespective of risk status. Additionally, the population-attributable risk for each risk factor was stable across the study period. For example, for maternal age 35 years or older at delivery, the number of cesarean deliveries attributable to this factor (the population-attributable risk) was 0.9 per 100 deliveries in 1992-1998 and 1 per 100 in 2014-2018. The proportion of cesarean deliveries in which nonreassuring fetal status was the indication increased from 30.1% in 1992 to 51.1% in 2018. The absolute rate of cesarean delivery in the second stage of labor increased from 3.1% in 1992 to 5.9% in 2018. This was due to a significant increase, among those who entered the second stage, in cesarean delivery without a trial of forceps, from 2.5% in 1992 to 7.0% in 2018. The observed doubling of the rate of cesarean delivery in labor in first-time mothers was not driven by patient risk factors. Increases in the rate of cesarean delivery for nonreassuring fetal status and decreased operative vaginal deliveries were important factors.

The Job of the Obstetrician Does Not End by the Delivery of the Fetus With Non-reassuring Status [38O

INTRODUCTION: Research generally focuses on neonatal outcomes when pregnancy is complicated by non-reassuring fetal status. Little attention has been directed to maternal outcomes after such deliveries. METHODS: A retrospective cohort study of 27,886 pregnancies at a single health system evaluated fetal status and postpartum maternal characteristics. Fetal heart tracing, arterial cord pH, maternal blood transfusion, and maternal ICU admission were among the evaluated characteristics. Multivariate logistic regression analyses were performed to assess correlation with markers of fetal well-being and maternal outcomes and adjusted odds ratios (AOR) were derived. RESULTS: Umbilical artery pH less than 7.0 was associated with transfusion (AOR 6.83 [95% CI 2.22–21.0, P&lt;.001]), cesarean delivery (AOR 5.76 [95% CI 3.63–9.15, P&lt;.0001]), and maternal readmission (AOR 12.6 [95% CI 2.26–69.8, P=.0039]). Fetal bradycardia events were associated with increased maternal ICU admission (AOR 3.22 [95% CI 1.23–8.46, P&lt;.017]), transfusion (AOR 2.13 [95% CI 1.26–3.59, P&lt;.005]) and readmission (AOR 4.17 [95% CI 1.16–15.0, P&lt;.029]). Late decelerations were associated with cesarean delivery (AOR 1.65 [95% CI 1.55–1.76, P&lt;.0001]), maternal readmission (AOR 1.24 [95% CI 1.01–1.53, P=.04]), chorioamnionitis (AOR 2.88 [95% CI 2.46–3.37, P&lt;.0001]), and maternal need for antibiotics (AOR 1.89 [95% CI 1.66–2.15, P&lt;.0001]). CONCLUSION: Non-reassuring fetal status is associated with significant risks to the mother as evidenced by significant increases in transfusions, ICU admissions, and readmissions. Obstetricians should remain vigilant after delivery for non-reassuring fetal status and focus on monitoring and optimization of maternal status.

Prelabor screening at term using the cerebroplacental ratio and placental growth factor: a pragmatic randomized open-label phase 2 trial

In some women placental function may not be adequate to meet fetal growth requirements in late pregnancy or the additional demands during labor, thus predisposing these infants to intrapartum fetal compromise and subsequent serious morbidity and mortality. The objective of this study was to determine if the introduction of a prelabor screening test at term combining the cerebroplacental ratio and maternal placental growth factor level would result in a reduction in a composite of adverse outcomes. Single-site, nonblinded, randomized controlled trial conducted at a tertiary hospital in Brisbane, Australia. Eligible women were randomized to either receive the screening test performed between 37-38 weeks or routine obstetric care. Screen-positive women were offered induction of labor. The primary outcome was a composite of emergency cesarean delivery for nonreassuring fetal status (fetal distress) or severe neonatal acidosis or low Apgar score or stillbirth or neonatal death. Women were recruited and randomized (n= 501) between April 2017 and January 2019. Sixty-three of 249 subjects (25.3%) in the screened group compared to 56 of 252 (22.2%) in the control group experienced the primary outcome (relative risk= 1.14 [95% confidence interval, 0.83-1.56]; P= .418). Women who screened positive were more likely to require operative delivery for fetal distress, have meconium-stained liquor, have pathologic fetal heart rate abnormalities, and have infants with lower birthweight compared to women that screened negative. The introduction of this test did not result in improvements in intrapartum intervention rates or neonatal outcomes. However, it did show discriminatory potential, and future research should focus on refining the thresholds used.

The Association between Maternal Race and Ethnicity and Risk Factors for Primary Cesarean Delivery in Nulliparous Women

To understand whether maternal, perinatal, and systems-level factors can be identified to explain racial/ethnic disparities in cesarean delivery rates. This retrospective cohort study included nulliparous women with singleton gestations who delivered at a tertiary care center from 2015 to 2017. Maternal, perinatal, and systems-level factors were compared by race/ethnicity. Multilevel multivariable logistic regression was used to identify whether race/ethnicity was independently associated with cesarean. Effect modification was evaluated using interaction terms. Bivariable analyses and multinomial logistic regression were used to determine differences in indication for cesarean. Of 9,865 eligible women, 2,126 (21.5%) delivered via cesarean. The frequency of cesarean was lowest in non-Hispanic white women (19.2%) and highest in non-Hispanic black women (28.2%; p < 0.001). Accounting for factors associated with cesarean delivery did not lessen the odds of cesarean associated with non-Hispanic black race (aOR: 1.58, 95% CI: 1.31-1.91). Compared with non-Hispanic white women, non-Hispanic black women were more likely to undergo cesarean for nonreassuring fetal status (aOR: 2.73, 95% CI: 2.06-3.61). Examined maternal, perinatal, and systems-level risk factors for cesarean delivery did not explain the racial/ethnic disparities observed in cesarean delivery rates. Increased cesarean delivery for nonreassuring fetal status contributed substantially to this disparity.

Detection of Adverse Perinatal Outcomes at Term Delivery Using Ultrasound Estimated Percentile Weight at 35 Weeks of Gestation: Comparison of Five Fetal Growth Standards

Objective: To assess the predictive ability of the ultrasound estimated percentile weight (EPW) at 35 weeks of pregnancy to predict adverse perinatal outcomes (APOs) at term delivery according to 5 fetal growth standards, including population, population-customized, and international references. Methods: This was a retrospective cohort study of 9,585 singleton pregnancies. Maternal clinical characteristics, fetal ultrasound data obtained at 35 weeks and pregnancy and perinatal outcomes were used to calculate EPWs to predict APOs according to: the customized and noncustomized (NC) Miguel Servet University Hospital (MSUH), the customized Figueras, the NC INTERGROWTH-21st, and the NC World Health Organization (WHO) international standards. APOs were defined as the occurrence of cesarean or instrumental delivery for nonreassuring fetal status, 5-min Apgar score < 7, arterial cord blood pH <7.10, or stillbirth. The predictive ability of EPW for APOs was analyzed using the area under the curve (AUC), and sensitivities were calculated for different false-positive rates (FPRs). Results: For a 10% FPR, detection rates for total APOs ranged between 12.7% with the customized MSUH (AUC 0.52; 95% CI 0.50–0.55) and 14.4% with the NC MSUH standard (AUC 0.55; 95% CI 0.53–0.57) for EPW by ultrasound; and from 22.0% with the customized MSUH standard (AUC 0.60; 95% CI 0.58–0.63) to 27.8% with the NC WHO (AUC 0.65; 95% CI 0.63–0.68) for EPW at delivery. Conclusions: The predictive capacity of the EPW for APOS is limited and similar, by both ultrasound and at delivery, for the 5 growth standards, without significant differences between customized and NC standards.

A comparison of vaginal versus buccal misoprostol for cervical ripening in women for labor induction at term (the IMPROVE trial): a triple-masked randomized controlled trial

Cervical ripening is commonly needed for labor induction. Finding an optimal route of misoprostol dosing for efficacy, safety, and patient satisfaction is important and not well studied for the buccal route. To compare the efficacy and safety of vaginal and buccal misoprostol for women undergoing labor induction at term. The IMPROVE trial was an institutional review board-approved, triple-masked, placebo-controlled randomized noninferiority trial for women undergoing labor induction at term with a Bishop score ≤6. Enrolled women received 25 mcg (first dose), then 50 mcg (subsequent doses) of misoprostol by assigned route (vaginal or buccal) and a matching placebo tablet by the opposite route. The primary outcomes were time to delivery and the rate of cesarean delivery performed urgently for fetal nonreassurance. A sample size of 300 was planned to test the noninferiority hypothesis. The trial enrolled 319 women, with 300 available for analysis, 152 in the vaginal misoprostol group and 148 in the buccal. Groups had similar baseline characteristics. We were unable to demonstrate noninferiority. The time to vaginal delivery was lower for the vaginal misoprostol group (median [95% confidence interval] in hours: vaginal: 20.1 [18.2, 22.8] vs buccal: 28.1 [24.1, 31.4], log-rank test P= .006, Pnoninferiority= .663). The rate of cesarean deliveries for nonreassuring fetal status was 3.3% for the vaginal misoprostol group and 9.5% for the buccal misoprostol group (P= .033). The rate of vaginal delivery in <24 hours was higher in the vaginal group (58.6% vs 39.2%, P= .001). We were unable to demonstrate noninferiority. In leading to a higher rate of vaginal deliveries, more rapid vaginal delivery, and fewer cesareans for fetal issues, vaginal misoprostol may be superior to buccal misoprostol for cervical ripening at term.

Prostaglandins and cesarean delivery for nonreassuring fetal status in patients delivering small-for-gestational age neonates at term

Objective: Growth-restricted fetuses have been excluded from many randomized trials of prostaglandins for labor induction. As prostaglandins, particularly misoprostol, are associated with increased rates of cesarean delivery for nonreassuring fetal heart tracing, it is important to assess their safety in pregnancies at higher risk of this complication. The objective of this study was to estimate the association between use of prostaglandins for labor induction in term singleton pregnancies complicated by delivery of small-for-gestational age (SGA) neonates and the risk of cesarean delivery for nonreassuring fetal status (NRFS).Materials and methods: Retrospective cohort study of singleton deliveries ≥37 weeks following induction of labor in patients with SGA (birthweight <10% percentile for gestational age). Patients with prior cesarean delivery or neonates with major congenital anomalies were excluded. Patients were categorized by exposure to prostaglandins. The primary outcome was cesarean delivery for NRFS. Secondary outcomes were any cesarean delivery, a composite of a 5-min Apgar score <7, admission to the neonatal intensive care unit, or neonatal death, and a composite of maternal morbidity (transfusion, postpartum hemorrhage, wound infection, endometritis, fever). Propensity scores for exposure were estimated using a logistic regression model, including parity, comorbidities, and Bishop score. Stabilized weights from inverse probability of treatment weighting were used. Outcomes were compared with relative risks (RRs) and 95% confidence intervals (CIs).Results: There were 1097 patients: 587 (53.5%) exposed to prostaglandins and 510 (46.5%) unexposed. Covariates were balanced in the stabilized sample. Overall, 166 (15.1%) patients had cesarean deliveries for NRFS. In unadjusted analysis, prostaglandin use was associated with an increased RR of cesarean for NRFS (18.3 versus 11.0%, RR: 1.71, 95% CI: 1.27–2.30). In propensity-score-weighted analysis, the RR for cesarean for NRFS was 1.22 (95% CI: 0.93–1.59). There was no significant association between prostaglandin exposure and all-cause cesarean delivery, maternal morbidity, or neonatal morbidity.Conclusion: In propensity score analysis, there was no association between the use of prostaglandins for labor induction at term and cesarean for NRFS in pregnancies complicated by SGA. However, given the retrospective nature of the study, these results should be interpreted with caution.

Effect of Oxygen vs Room Air on Intrauterine Fetal Resuscitation

Two-thirds of women in labor receive supplemental oxygen to reverse perceived fetal hypoxemia and prevent acidemia. Oxygen is routinely administered for category II fetal heart tracings, a class of fetal tracing used to designate intermediate risk for acidemia. This liberal use of oxygen may not be beneficial, particularly because neonatal hyperoxygenation is harmful. To test the hypothesis that room air is noninferior to oxygen in improving fetal metabolic status among patients with category II fetal heart tracings. This was a randomized, unblinded noninferiority clinical trial conducted between June 2016 and July 2017 in the labor and delivery ward of a single tertiary care center. Women with singleton pregnancies at 37 weeks' gestational age or more who were admitted for delivery were eligible. Of those who met inclusion criteria, the patients who developed category II tracings in labor that necessitated intrauterine resuscitation were randomized in a 1:1 ratio to room air or oxygen. Analyses were intention-to-treat. The oxygen group received 10 L of oxygen per minute by nonrebreather facemask until delivery. The room air group was exposed to room air only without a facemask. The primary outcome was umbilical artery lactate, a marker of metabolic acidosis and neonatal morbidity. Noninferiority was defined as a mean difference between groups of less than 9.0 mg/dL (1.0 mmol/L). Secondary outcomes were other umbilical artery gases, cesarean delivery for nonreassuring fetal status, and operative vaginal delivery. Of the 705 patients who met inclusion criteria, 277 (39.3%) were enrolled on admission. During labor, 114 patients (41.2% of the enrolled patients) developed category II tracings and were randomized to room air (57 patients; 50.0% of the randomized patients) or oxygen (57 patients; 50.0% of the randomized patients). A total of 99 patients (86.8% of the randomized patients) with paired cord gases were included in the modified intention-to-treat analysis. The 99 patients included 76 African American women (77%); mean (SD) age was 27.3 (6.3) years in the oxygen group and 27.8 (5.3) years in the room air group. There was no difference in umbilical artery lactate between the group on oxygen and the group on room air (mean, 30.6 mg/dL [95% CI, 27.0 to 34.2 mg/dL] vs 31.5 mg/dL [95% CI, 27.9 to 36.0 mg/dL]); P = .69). The mean difference in lactate was 0.9 mg/dL (95% CI, -4.5 to 6.3 mg/dL), which was within the noninferiority margin. There was no difference in other umbilical artery gas components or mode of delivery between groups. Among patients with category II fetal heart tracings, intrauterine resuscitation with room air is noninferior to oxygen in improving umbilical artery lactate. The results of this trial challenge the efficacy of a ubiquitous obstetric practice and suggest that room air may be an acceptable alternative. ClinicalTrials.gov Identifier: NCT02741284.