Third stage of labor: evidence-based practice for prevention of adverse maternal and neonatal outcomes.

The third stage of labor is defined as the time period between delivery of the fetus through delivery of the placenta. During a normal third stage, uterine contractions lead to separation and expulsion of the placenta from the uterus. Postpartum hemorrhage is a relatively common complication of the third stage of labor. Strategies have been studied to mitigate the risk of postpartum hemorrhage, leading to the widespread implementation of active management of the third stage of labor. Initially, active management of the third stage of labor consisted of a bundle of interventions including administration of a uterotonic agent, early cord clamping, controlled cord traction, and external uterine massage. However, the effectiveness of these interventions as a bundle has been questioned, leading to abandonment of some components in recent years. Despite this, upon review of selected international guidelines, we found that the term "active management of the third stage of labor" was still used, but recommendations for and against individual interventions were variable and not necessarily supported by current evidence. In this review, we: (1) examine the physiology of the third stage of labor, (2) present evidence related to interventions that prevent postpartum hemorrhage and promote maternal and neonatal health, (3) review current global guidelines and recommendations for practice, and (4) propose future areas of investigation. The interventions in this review include pharmacologic agents to prevent postpartum hemorrhage, cord clamping, cord milking, cord traction, cord drainage, early skin-to-skin contact, and nipple stimulation. Treatment of complications of the third stage of labor is outside of the scope of this review. We conclude that current evidence supports the use of effective pharmacologic postpartum hemorrhage prophylaxis, delayed cord clamping, early skin-to-skin contact, and controlled cord traction at delivery when feasible. The most effective uterotonic regimens for preventing postpartum hemorrhage after vaginal delivery include oxytocin plus ergometrine; oxytocin plus misoprostol; or carbetocin. After cesarean delivery, carbetocin or oxytocin as a bolus are the most effective regimens. There is inconsistent evidence regarding the use of tranexamic acid in addition to a uterotonic compared with a uterotonic alone for postpartum hemorrhage prevention after all deliveries. Because of differences in patient comorbidities, costs, and availability of resources and staff, decisions to use specific prevention strategies are dependent on patient- and system-level factors. We recommend that the term "active management of the third stage of labor" as a combined intervention no longer be used. Instead, we recommend that "third stage care" be adopted, which promotes the implementation of evidence-based interventions that incorporate practices that are safe and beneficial for both the woman and neonate.

Racial and Ethnic Disparities in Adverse Perinatal Outcomes at Term.

OBJECTIVE: This study aimed to evaluate whether racial and ethnic disparities in adverse perinatal outcomes exist at term. STUDY DESIGN: We performed a secondary analysis of a multicenter observational study of 115,502 pregnant patients and their neonates (2008-2011). Singleton, nonanomalous pregnancies delivered from 37 to 41 weeks were included. Race and ethnicity were abstracted from the medical record and categorized as non-Hispanic White (White; referent), non-Hispanic Black (Black), non-Hispanic Asian (Asian), or Hispanic. The primary outcome was an adverse perinatal composite defined as perinatal death, Apgar score < 4 at 5 minutes, ventilator support, hypoxic-ischemic encephalopathy, subgaleal hemorrhage, skeletal fracture, infant stay greater than maternal stay (by ≥ 3 days), brachial plexus palsy, or facial nerve palsy. RESULTS: Of the 72,117 patients included, 48% were White, 20% Black, 5% Asian, and 26% Hispanic. The unadjusted risk of the primary outcome was highest for neonates of Black patients (3.1%, unadjusted relative risk [uRR] = 1.16, 95% confidence interval [CI]: 1.04-1.30), lowest for neonates of Hispanic patients (2.1%, uRR = 0.80, 95% CI: 0.71-0.89), and no different for neonates of Asian (2.6%), compared with those of White patients (2.7%). In the adjusted model including age, body mass index (BMI), smoking, obstetric history, and high-risk pregnancy, differences in risk for the primary outcome were no longer observed for neonates of Black (adjusted relative risk [aRR] = 1.06, 95% CI: 0.94-1.19) and Hispanic (aRR = 0.92, 95% CI: 0.81-1.04) patients. Adding insurance to the model lowered the risk for both groups (aRR = 0.85, 95% CI: 0.75-0.96 for Black; aRR = 0.68, 95% CI: 0.59-0.78 for Hispanic). CONCLUSION: Although neonates of Black patients have the highest frequency of adverse perinatal outcomes at term, after adjustment for sociodemographic factors, this higher risk is no longer observed, suggesting the importance of developing strategies that address social determinants of health to lessen extant health disparities. KEY POINTS: · Term neonates of Black patients have the highest crude frequency of adverse perinatal outcomes.. · After adjustment for confounders, higher risk for neonates of Black patients is no longer observed.. · Disparities in outcomes are strongly related to insurance status..

Evaluation of Hypoglycemia in Neonates of Women at Risk for Late Preterm Delivery: An Antenatal Late Preterm Steroids Trial Cohort Study.

OBJECTIVE: In the antenatal late preterm steroids (ALPS) trial betamethasone significantly decreased short-term neonatal respiratory morbidity but increased the risk of neonatal hypoglycemia, diagnosed only categorically (<40 mg/dL). We sought to better characterize the nature, duration, and treatment for hypoglycemia. STUDY DESIGN: Secondary analysis of infants from ALPS, a multicenter trial randomizing women at risk for late preterm delivery to betamethasone or placebo. This study was a reabstraction of all available charts from the parent trial, all of which were requested. Unreviewed charts included those lost to follow-up or from sites not participating in the reabstraction. Duration of hypoglycemia (<40 mg/dL), lowest value and treatment, if any, were assessed by group. Measures of association and regression models were used where appropriate. RESULTS: Of 2,831 randomized, 2,609 (92.2%) were included. There were 387 (29.3%) and 223 (17.3%) with hypoglycemia in the betamethasone and placebo groups, respectively (relative risk [RR]: 1.69, 95% confidence interval [CI]: 1.46-1.96). Hypoglycemia generally occurred in the first 24 hours in both groups: 374/385 (97.1%) in the betamethasone group and 214/222 (96.4%) in the placebo group (p = 0.63). Of 387 neonates with hypoglycemia in the betamethasone group, 132 (34.1%) received treatment, while 73/223 (32.7%) received treatment in placebo group (p = 0.73). The lowest recorded blood sugar was similar between groups. Most hypoglycemia resolved by 24 hours in both (93.0 vs. 89.3% in the betamethasone and placebo groups, respectively, p = 0.18). Among infants with hypoglycemia in the first 24 hours, the time to resolution was shorter in the betamethasone group (2.80 [interquartile range: 2.03-7.03) vs. 3.74 (interquartile range: 2.15-15.08) hours; p = 0.002]. Persistence for >72 hours was rare and similar in both groups, nine (2.4%, betamethasone) and four (1.9%, placebo, p = 0.18). CONCLUSION: In this cohort, hypoglycemia was transient and most received no treatment, with a quicker resolution in the betamethasone group. Prolonged hypoglycemia was uncommon irrespective of steroid exposure. KEY POINTS: · Hypoglycemia was transient and approximately two-thirds received no treatment.. · Neonates in the ALPS trial who received betamethasone had a shorter time to resolution than those with hypoglycemia in the placebo group.. · Prolonged hypoglycemia occurred in approximately 2 out of 100 late preterm newborns, irrespective of antenatal steroid exposure..

Pregnancy Outcomes Associated With Use of Tobacco and Marijuana.

Tobacco and marijuana are the most common drugs of abuse among pregnant women. Cigarettes have been extensively studied and increase the risk of miscarriage, preterm birth, premature rupture of membranes, placental dysfunction, low birth rate, stillbirth, and infant mortality. There are sparse data on the specific effects of electronic cigarettes and smokeless tobacco in pregnancy. Literature on marijuana in pregnancy is limited by confounding, bias, and the retrospective nature of studies that do not capture contemporary trends in use. However, several studies suggest an association between marijuana and fetal growth restriction, low birth weight, and neurodevelopmental differences in offspring.

Comparison of Cesarean Deliveries in a Multicenter U.S. Cohort Using the 10-Group Classification System.

OBJECTIVE: We sought to (1) use the Robson 10-Group Classification System (TGCS), which classifies deliveries into 10 mutually exclusive groups, to characterize the groups that are primary contributors to cesarean delivery frequencies, (2) describe inter-hospital variations in cesarean delivery frequencies, and (3) evaluate the contribution of patient characteristics by TGCS group to hospital variation in cesarean delivery frequencies. STUDY DESIGN: This was a secondary analysis of an observational cohort of 115,502 deliveries from 25 hospitals between 2008 and 2011. The TGCS was applied to the cohort and each hospital. We identified and compared the TGCS groups with the greatest relative contributions to cohort and hospital cesarean delivery frequencies. We assessed variation in hospital cesarean deliveries attributable to patient characteristics within TGCS groups using hierarchical logistic regression. RESULTS: A total of 115,211 patients were classifiable in the TGCS (99.7%). The cohort cesarean delivery frequency was 31.4% (hospital range: 19.1-39.3%). Term singletons in vertex presentation with a prior cesarean delivery (group 5) were the greatest relative contributor to cohort (34.8%) and hospital cesarean delivery frequencies (median: 33.6%; range: 23.8-45.5%). Nulliparous term singletons in vertex (NTSV) presentation (groups 1 [spontaneous labor] and 2 [induced or absent labor]: 28.9%), term singletons in vertex presentation with a prior cesarean delivery (group 5: 34.8%), and preterm singletons in vertex presentation (group 10: 9.8%) contributed to 73.2% of the relative cesarean delivery frequency for the cohort and were correlated with hospital cesarean delivery frequencies (Spearman's rho = 0.96). Differences in patient characteristics accounted for 34.1% of hospital-level cesarean delivery variation in group 2. CONCLUSION: The TGCS highlights the contribution of NTSV presentation to cesarean delivery frequencies and the impact of patient characteristics on hospital-level variation in cesarean deliveries among nulliparous patients with induced or absent labor. KEY POINTS: · We report on the cesarean delivery frequencies in a multicenter U.S. COHORT: . · NTSV gestations (groups 1 and 2) are a primary driver of cesarean deliveries.. · Patient characteristics contributed most to hospital variation in cesarean deliveries in group 2..

Association of Maternal Body Mass Index and Maternal Morbidity And Mortality.

OBJECTIVE: This study aimed to assess the association of maternal body mass index (BMI) with a composite of severe maternal outcomes. STUDY DESIGN: Secondary analysis of a cohort of deliveries on randomly selected days at 25 hospitals from 2008 to 2011. Data on comorbid conditions, intrapartum events, and postpartum course were collected. The reference group (REF, BMI: 18.5-29.9kg/m2), obese (OB; BMI: 30-39.9kg/m2), morbidly obese (MO; BMI: 40-49.9kg/m2), and super morbidly obese (SMO; BMI ≥ 50kg/m2) women were compared. The composite of severe maternal outcomes was defined as death, intensive care unit (ICU) admission, ventilator use, deep venous thrombosis/pulmonary embolus (DVT/PE), sepsis, hemorrhage, disseminated intravascular coagulation (DIC), unplanned operative procedure, or stroke. Patients in the REF group were matched 1:1 with those in all other obesity groups based on propensity score using the baseline characteristics of age, race/ethnicity, previous cesarean, preexisting diabetes, chronic hypertension, parity, cigarette use, and insurance status. Multivariable Poisson's regression was used to estimate adjusted relative risks (aRRs) and 95% confidence intervals (CIs) for the association between BMI and the composite outcome. Because cesarean delivery may be in the causal pathway between obesity and adverse maternal outcomes, models were then adjusted for mode of delivery to evaluate potential mediation. RESULTS: A total of 52,162 pregnant patients are included in the analysis. Risk of composite maternal outcomes was increased for SMO compared with REF but not for OB and MO [OB: aRR=1.06, 95% CI: 0.99-1.14; MO: aRR=1.10, 95% CI: 0.97-1.25; SMO: aRR=1.32, 95% CI: 1.02-1.70]. However, in the mediation analysis, cesarean appears to mediate 46% (95% CI: 31-50%) of the risk of severe morbidity for SMO compared with REF. CONCLUSION: Super morbid obesity is significantly associated with increased serious maternal morbidity and mortality; however, cesarean appears to mediate this association. Obesity and morbid obesity are not associated with maternal morbidity and mortality. KEY POINTS: · Super morbid obesity is associated with increased morbidity.. · Cesarean appears to mediate the association between super morbid obesity and morbidity.. · Obesity and morbid maternal obesity are not associated with morbidity..

A Model to Predict Vaginal Delivery and Maternal and Neonatal Morbidity in Low-Risk Nulliparous Patients at Term.

OBJECTIVE: This study aimed to develop and validate a model to predict the probability of vaginal delivery (VD) in low-risk term nulliparous patients, and to determine whether it can predict the risk of severe maternal and neonatal morbidity. METHODS: Secondary analysis of an obstetric cohort of patients and their neonates born in 25 hospitals across the United States (n = 115,502). Trained and certified research personnel abstracted the maternal and neonatal records. Nulliparous patients with singleton, nonanomalous vertex fetuses, admitted with an intent for VD ≥ 37 weeks were included in this analysis. Patients in active labor (cervical exam > 5 cm), those with prior cesarean and other comorbidities were excluded. Eligible patients were randomly divided into a training and test sets. Based on the training set, and using factors available at the time of admission for delivery, we developed and validated a logistic regression model to predict the probability of VD, and then estimated the prevalences of severe morbidity according to the predicted probability of VD. RESULTS: A total of 19,611 patients were included. Based on the training set (n = 9,739), a logistic regression model was developed that included maternal age, body mass index (BMI), cervical dilatation, and gestational age on admission. The model was internally validated on the test set (n = 9,872 patients) and yielded a receiver operating characteristic-area under the curve (ROC-AUC) of 0.71 (95% confidence interval [CI]: 0.70-0.72). Based on a subset of 18,803 patients with calculated predicted probabilities, we demonstrated that the prevalences of severe morbidity decreased as the predicted probability of VD increased (p < 0.01). CONCLUSION: In a large cohort of low-risk nulliparous patients in early labor or undergoing induction of labor, at term with singleton gestations, we developed and validated a model to calculate the probability of VD, and maternal and neonatal morbidity. If externally validated, this calculator may be clinically useful in helping to direct level of care, staffing, and adjustment for case-mix among various systems. KEY POINTS: · A model to predict the probability of vaginal delivery in low-risk nulliparous patients at term.. · The model also predicts the risk of severe maternal and neonatal morbidity.. · The prevalences of severe morbidity decrease as the probability of vaginal delivery increases..

Labor Induction at 39 Weeks Compared with Expectant Management in Low-Risk Parous Women.

OBJECTIVE: Our objective was to compare outcomes among low-risk parous women who underwent elective labor induction at 39 weeks versus expectant management. STUDY DESIGN: This is a secondary analysis of an observational cohort of 115,502 mother-infant dyads who delivered at 25 hospitals between 2008 and 2011. The inclusion criteria for this analysis were low-risk parous women with nonanomalous singletons with at least one prior vaginal delivery after 20 weeks, who delivered at ≥390/7 weeks. Women who electively induced between 390/7 and 396/7 weeks were compared with women who expectantly managed ≥390/7 weeks. The primary outcome for this analysis was cesarean delivery. Secondary outcomes were composites of maternal adverse outcome and neonatal adverse outcome. Multivariable logistic regression was used to estimate adjusted odds ratios (aOR). RESULTS: Of 20,822 women who met inclusion criteria, 2,648 (12.7%) were electively induced at 39 weeks. Cesarean delivery was lower among women who underwent elective induction at 39 weeks than those who did not (2.4 vs. 4.6%, adjusted odds ratio [aOR]: 0.70, 95% confidence interval [CI]: 0.53-0.92). The frequency of the composite maternal adverse outcome was significantly lower for the elective induction cohort as well (1.6 vs. 3.1%, aOR: 0.66, 95% CI: 0.47-0.93). The composite neonatal adverse outcome was not significantly different between the two groups (0.3 vs. 0.6%; aOR: 0.60, 95% CI: 0.29-1.23). CONCLUSION: In low-risk parous women, elective induction of labor at 39 weeks was associated with decreased odds of cesarean delivery and maternal morbidity, without an increase in neonatal adverse outcomes. KEY POINTS: · 39-week elective induction is associated with decreased cesarean delivery in low-risk parous women.. · Compared with expectant management, maternal adverse outcomes were lower with elective induction.. · Neonatal adverse outcomes are unchanged between elective and expectant management groups..

Antenatal Corticosteroids and Preterm Neonatal Morbidity and Mortality among Women with and without Diabetes in Pregnancy.

OBJECTIVE: The objective of this study was to determine whether antenatal corticosteroid exposure has a differential association with preterm neonatal morbidity among women with and without diabetes. STUDY DESIGN: Secondary analysis of an observational cohort of 115,502 women and their neonates born in 25 U.S. hospitals (2008-2011). Women who delivered at 230/7 to 336/7 weeks' gestation and received antenatal corticosteroids were compared with those who did not receive antenatal corticosteroids. Women with a stillbirth and women who delivered a neonate that was not resuscitated were excluded. The primary outcome was neonatal respiratory distress syndrome or death within 48 hours. Secondary outcomes included composite neonatal morbidity (respiratory distress syndrome, necrotizing enterocolitis, grades 3-4 intraventricular hemorrhage, sepsis, or death) and mechanical ventilation. Multivariable modified Poisson regression was used to estimate the association between antenatal corticosteroid exposure and neonatal outcomes. Maternal diabetes (pregestational and gestational) was evaluated as a potential effect modifier, and sensitivity analyses were conducted to evaluate whether receipt of a partial, single, or multiple course(s) of antenatal corticosteroids influenced results. RESULTS: A total of 4,429 women with 5,259 neonates met inclusion criteria: 3,716 (83.9%) women received antenatal corticosteroids and 713 (16.1%) did not. Of the 510 diabetic women (181 pregestational and 329 gestational), 439 (86.1%) received antenatal corticosteroids. Of the 3,919 nondiabetic women, 3,277 (83.6%) received antenatal corticosteroids. Antenatal corticosteroid exposure was not associated with respiratory distress syndrome or early death (adjusted relative risk [aRR] = 0.94, 95% confidence interval [CI]: 0.85-1.04), composite neonatal morbidity (aRR = 0.98, 95% CI: 0.89-1.07), or mechanical ventilation (aRR = 0.95, 95% CI: 0.86-1.05). There was no significant effect modification of maternal diabetes on the relationship between antenatal corticosteroids and neonatal outcomes (p > 0.05), and outcomes were similar in sensitivity analyses of partial, single, or multiple courses of corticosteroids. DISCUSSION: Antenatal corticosteroid administered to reduce preterm neonatal morbidity does not appear to have a differential association among women with diabetes compared with those without. KEY POINTS: · Antenatal corticosteroids are used ubiquitously in women with and without diabetes.. · Maternal diabetes does not appear to modify the neonatal effect of antenatal corticosteroids.. · Larger studies of antenatal corticosteroids are needed to confirm our findings in diabetic women..

Association between Hypertensive Disorders of Pregnancy and Long-Term Neurodevelopmental Outcomes in the Offspring.

OBJECTIVE: The long-term impact of hypertensive disorders of pregnancy (HDP) exposure on offspring health is an emerging research area. The objective of this study was to evaluate the association between a maternal diagnosis of HDP (gestational hypertension and preeclampsia) and adverse neurodevelopmental outcomes in the offspring. STUDY DESIGN: This was a secondary analysis of two parallel multicenter clinical trials of thyroxine therapy for subclinical hypothyroid disorders in pregnancy. Women with singleton nonanomalous gestations diagnosed with subclinical hypothyroidism or hypothyroxinemia were randomized to thyroxine therapy or placebo. The primary outcome was child intelligence quotient (IQ) at 5 years of age. Secondary outcomes included several neurodevelopmental measures, including the Bayley-III cognitive, motor, and language scores at 12 and 24 months, Differential Ability Scales-II (DAS-II) scores at 36 months, the Conners' rating scales-revised at 48 months, and scores from the Child Behavior Checklist at 36 and 60 months. Thyroxine therapy did not influence neurodevelopment in either of the primary studies. Associations between neurodevelopment outcomes and maternal HDP were examined using univariable and multivariable analyses. RESULTS: A total of 112 woman-child dyads with HDP were compared with 1,067 woman-child dyads without HDP. In univariable analysis, mean maternal age (26.7 ± 5.9 vs. 27.8 ± 5.7 years, p = 0.032) and the frequency of nulliparity (45.5 vs. 31.0%, p = 0.002) differed significantly between the two groups. Maternal socioeconomic characteristics did not differ between the groups. After adjusting for potential confounders, there were no significant differences in any primary or secondary neurodevelopment outcome between offspring exposed to HDP and those unexposed. However, when dichotomized as low or high scores, we found higher rates of language delay (language scores <85: -1 standard deviation) at 2 years of age among offspring exposed to HDP compared with those unexposed (46.5 vs. 30.5%, adjusted odds ratio = 2.22, 95% confidence interval [CI]: 1.44-3.42). CONCLUSION: In this cohort of pregnant women, HDP diagnosis was associated with language delay at 2 years of age. However, other long-term neurodevelopmental outcomes in offspring were not associated with HDP. KEY POINTS: · No differences were found in neurodevelopment between offspring exposed to HDP and controls.. · Higher rates of language delay at 2 years of age were found in offspring exposed to HDP.. · The results did not differ when analysis was stratified by preterm birth..

Obstacles to Optimal Antenatal Corticosteroid Administration to Eligible Patients.

OBJECTIVE: Administration of antenatal corticosteroids (ANCS) is recommended for individuals expected to deliver between 24 and 34 weeks of gestation. Properly timed administration of ANCS achieves maximal benefit. However, more than 50% of individuals receive ANCS outside the recommended window. This study aimed to examine maternal and hospital factors associated with suboptimal receipt of ANCS among individuals who deliver between 24 and 34 weeks of gestation. STUDY DESIGN: Secondary analysis of the Assessment of Perinatal Excellence (APEX), an observational study of births to 115,502 individuals at 25 hospitals in the United States from March 2008 to February 2011, was conducted. Data from 3,123 individuals who gave birth to a nonanomalous live-born infant between 240/7 to 340/7 weeks of gestation, had prenatal records available at delivery, and data available on the timing of ANCS use were included in this analysis. Eligible individuals' ANCS status was categorized as optimal (full course completed >24 hours after ANCS but not >7 days before birth) or suboptimal (none, too late, or too early). Maternal and hospital-level variables were compared using optimal as the referent group. Hierarchical multinomial logistic regression models, with site as a random effect, were used to identify maternal and hospital-level characteristics associated with optimal ANCS use. RESULTS: Overall, 83.6% (2,612/3,123) of eligible individuals received any treatment: 1,216 (38.9%) optimal and 1,907 (61.1%) suboptimal. Within suboptimal group, 495 (15.9%) received ANCS too late, 901 (28.9%) too early, and 511 (16.4%) did not receive any ANCS. Optimal ANCS varied depending on indication for hospital admission (p < 0.001). Individuals who were admitted with intent to deliver were less likely to receive optimal ANCS while individuals admitted for hypertensive diseases of pregnancy were most likely to receive optimal ANCS (10 vs. 35%). The median gestational age of individuals who received optimal ANCS was 31.0 weeks. Adjusting for hospital factors, hospitals with electronic medical records and who receive transfers have fewer eligible individuals who did not receive ANCS. ANCS administration and timing varied substantially by hospital, optimal frequencies ranged from 9.1 to 51.3%, and none frequencies from 6.1 to 61.8%. When evaluating variation by hospital site, models with maternal and hospital factors did not explain any of the variation in ANCS use. CONCLUSION: Optimal ANCS use varied by maternal and hospital factors and by hospital site, indicating opportunities for improvement. KEY POINTS: · Majority of individuals who deliver between 24 and 34 weeks of gestation do not receive properly timed antenatal corticosteroids.. · Optimal use of antenatal corticosteroids varies by maternal and hospital factors and hospital site.. · Significant variation in hospital sites regarding optimally timed administration of antenatal corticosteroids indicates opportunities for improvement..

Differences in obstetrical care and outcomes associated with the proportion of the obstetrician's shift completed.

BACKGROUND: Understanding and improving obstetrical quality and safety is an important goal of professional societies, and many interventions such as checklists, safety bundles, educational interventions, or other culture changes have been implemented to improve the quality of care provided to obstetrical patients. Although many factors contribute to delivery decisions, a reduced workload has addressed how provider issues such as fatigue or behaviors surrounding impending shift changes may influence the delivery mode and outcomes. OBJECTIVE: The objective was to assess whether intrapartum obstetrical interventions and adverse outcomes differ based on the temporal proximity of the delivery to the attending's shift change. STUDY DESIGN: This was a secondary analysis from a multicenter obstetrical cohort in which all patients with cephalic, singleton gestations who attempted vaginal birth were eligible for inclusion. The primary exposure used to quantify the relationship between the proximity of the provider to their shift change and a delivery intervention was the ratio of time from the most recent attending shift change to vaginal delivery or decision for cesarean delivery to the total length of the shift. Ratios were used to represent the proportion of time completed in the shift by normalizing for varying shift lengths. A sensitivity analysis restricted to patients who were delivered by physicians working 12-hour shifts was performed. Outcomes chosen included cesarean delivery, episiotomy, third- or fourth-degree perineal laceration, 5-minute Apgar score of <4, and neonatal intensive care unit admission. Chi-squared tests were used to evaluate outcomes based on the proportion of the attending's shift completed. Adjusted and unadjusted logistic models fitting a cubic spline (when indicated) were used to determine whether the frequency of outcomes throughout the shift occurred in a statistically significant, nonlinear pattern RESULTS: Of the 82,851 patients eligible for inclusion, 47,262 (57%) had ratio data available and constituted the analyzable sample. Deliveries were evenly distributed throughout shifts, with 50.6% taking place in the first half of shifts. There were no statistically significant differences in the frequency of cesarean delivery, episiotomy, third- or fourth-degree perineal lacerations, or 5-minute Apgar scores of <4 based on the proportion of the shift completed. The findings were unchanged when evaluated with a cubic spline in unadjusted and adjusted logistic models. Sensitivity analyses performed on the 22.2% of patients who were delivered by a physician completing a 12-hour shift showed similar findings. There was a small increase in the frequency of neonatal intensive care unit admissions with a greater proportion of the shift completed (adjusted P=.009), but the findings did not persist in the sensitivity analysis. CONCLUSION: Clinically significant differences in obstetrical interventions and outcomes do not seem to exist based on the temporal proximity to the attending physician's shift change. Future work should attempt to directly study unit culture and provider fatigue to further investigate opportunities to improve obstetrical quality of care, and additional studies are needed to corroborate these findings in community settings.

Cervical length distribution and other sonographic ancillary findings of singleton nulliparous patients at midgestation.

BACKGROUND: Short cervix at midgestation, the presence of intraamniotic debris, and cervical funneling are risk factors for preterm birth; however, cervical length measurements and cutoffs are not well documented among pregnant patients of different gestational ages and self-reported races and ethnicities. OBJECTIVE: This study aimed to describe the distribution of cervical length and frequency of funneling and debris at midgestation in nulliparous women by gestational age and race/ethnicity. STUDY DESIGN: This secondary analysis of screening data from a multicenter treatment trial of singleton nulliparous patients with short cervix was conducted at 14 geographically distributed, university-affiliated medical centers in the United States. Singleton nulliparous patients with no known risk factors for preterm birth were screened for trial participation and asked to undergo a transvaginal ultrasound to measure cervical length by a certified sonographer. The distribution of cervical length and the frequency of funneling and debris were assessed for each gestational age week (16-22 weeks) and stratified by self-reported race and ethnicity, which for this study were categorized as White, Black, Hispanic, and other. Patients enrolled in the randomized trial were excluded from this analysis. RESULTS: A total of 12,407 nulliparous patients were included in this analysis. The racial or ethnic distribution of the study participants was as follows: White, 41.6%; Black, 29.6%; Hispanic, 24.2%; and others, 4.6%. The 10th percentile cervical length for the entire cohort was 31.1 mm and, when stratified by race and ethnicity, 31.9 mm for White, 30.2 mm for Black, 31.4 mm for Hispanic, and 31.2 mm for patients of other race and ethnicity (P<.001). At each gestational age, the cervical length corresponding to the tenth percentile was shorter in Black patients. The 25 mm value commonly used to define a short cervix and thought to represent the 10th percentile ranged from 1.3% to 5.4% across gestational age weeks and 1.0% to 3.8% across race and ethnicity groups. Black patients had the highest rate of funneling (2.6%), whereas Hispanic and Black patients had higher rates of intraamniotic debris than White and other patients (P<.001). CONCLUSION: Black patients had shorter cervical length and higher rates of debris and funneling than White patients. The racial and ethnic disparities in sonographic midtrimester cervical findings may provide insight into the racial disparity in preterm birth rates in the United States.

Duration of Operative Vaginal Delivery and Adverse Obstetric Outcomes.

OBJECTIVE: This study aimed to evaluate whether the number of vacuum pop-offs, the number of forceps pulls, or the duration of operative vaginal delivery (OVD) is associated with adverse maternal and perinatal outcomes. STUDY DESIGN: This is a secondary analysis of a multicenter observational cohort of women who underwent an attempted OVD. Women were stratified by the duration of OVD and the number of pop-offs (vacuum) or pulls (forceps) attempted. Severe perineal lacerations, failed OVD, and a composite adverse neonatal outcome were compared by the duration of OVD and number of pop-offs or pulls. RESULTS: Of the 115,502 women in the primary cohort, 5,325 (4.6%) underwent an attempt at OVD: 3,594 (67.5%) with vacuum and 1,731 (32.5%) with forceps. After adjusting for potential confounders, an increasing number of pop-offs was associated with an increased odds of the composite adverse neonatal outcome. However, an increasing duration of vacuum exhibited a stronger association with the composite adverse neonatal outcome. Similarly, the number of forceps pulls was less strongly associated with the composite adverse neonatal outcome compared with the duration of forceps application. CONCLUSION: The duration of OVD may be more associated with adverse neonatal outcomes than the number of pop-offs or pulls.

Association Between Features of Spontaneous Late Preterm Labor and Late Preterm Birth.

OBJECTIVE: This study aimed to evaluate the association between clinical and examination features at admission and late preterm birth. STUDY DESIGN: The present study is a secondary analysis of a randomized trial of singleton pregnancies at 340/7 to 365/7 weeks' gestation. We included women in spontaneous preterm labor with intact membranes and compared them by gestational age at delivery (preterm vs. term). We calculated a statistical cut-point optimizing the sensitivity and specificity of initial cervical dilation and effacement at predicting preterm birth and used multivariable regression to identify factors associated with late preterm delivery. RESULTS: A total of 431 out of 732 (59%) women delivered preterm. Cervical dilation ≥ 4 cm was 60% sensitive and 68% specific for late preterm birth. Cervical effacement ≥ 75% was 59% sensitive and 65% specific for late preterm birth. Earlier gestational age at randomization, nulliparity, and fetal malpresentation were associated with late preterm birth. The final regression model including clinical and examination features significantly improved late preterm birth prediction (81% sensitivity, 48% specificity, area under the curve = 0.72, 95% confidence interval [CI]: 0.68-0.75, and p-value < 0.01). CONCLUSION: Four in 10 women in late-preterm labor subsequently delivered at term. Combination of examination and clinical features (including parity and gestational age) improved late-preterm birth prediction.

Antenatal Betamethasone for Women at Risk for Late Preterm Delivery.

BACKGROUND: Infants who are born at 34 to 36 weeks of gestation (late preterm) are at greater risk for adverse respiratory and other outcomes than those born at 37 weeks of gestation or later. It is not known whether betamethasone administered to women at risk for late preterm delivery decreases the risks of neonatal morbidities. METHODS: We conducted a multicenter, randomized trial involving women with a singleton pregnancy at 34 weeks 0 days to 36 weeks 5 days of gestation who were at high risk for delivery during the late preterm period (up to 36 weeks 6 days). The participants were assigned to receive two injections of betamethasone or matching placebo 24 hours apart. The primary outcome was a neonatal composite of treatment in the first 72 hours (the use of continuous positive airway pressure or high-flow nasal cannula for at least 2 hours, supplemental oxygen with a fraction of inspired oxygen of at least 0.30 for at least 4 hours, extracorporeal membrane oxygenation, or mechanical ventilation) or stillbirth or neonatal death within 72 hours after delivery. RESULTS: The primary outcome occurred in 165 of 1427 infants (11.6%) in the betamethasone group and 202 of 1400 (14.4%) in the placebo group (relative risk in the betamethasone group, 0.80; 95% confidence interval [CI], 0.66 to 0.97; P=0.02). Severe respiratory complications, transient tachypnea of the newborn, surfactant use, and bronchopulmonary dysplasia also occurred significantly less frequently in the betamethasone group. There were no significant between-group differences in the incidence of chorioamnionitis or neonatal sepsis. Neonatal hypoglycemia was more common in the betamethasone group than in the placebo group (24.0% vs. 15.0%; relative risk, 1.60; 95% CI, 1.37 to 1.87; P<0.001). CONCLUSIONS: Administration of betamethasone to women at risk for late preterm delivery significantly reduced the rate of neonatal respiratory complications. (Funded by the National Heart, Lung, and Blood Institute and the Eunice Kennedy Shriver National Institute of Child Health and Human Development; ClinicalTrials.gov number, NCT01222247.).

Prophylactic oxytocin for the third stage of labour to prevent postpartum haemorrhage.

BACKGROUND: Active management of the third stage of labour reduces the risk of postpartum blood loss (postpartum haemorrhage (PPH)), and is defined as administration of a prophylactic uterotonic, early umbilical cord clamping and controlled cord traction to facilitate placental delivery. The choice of uterotonic varies across the globe and may have an impact on maternal outcomes. This is an update of a review first published in 2001 and last updated in 2013. OBJECTIVES: To determine the effectiveness of prophylactic oxytocin to prevent PPH and other adverse maternal outcomes in the third stage of labour. SEARCH METHODS: For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP) (6 March 2019) and reference lists of retrieved studies. SELECTION CRITERIA: Randomised, quasi- or cluster-randomised trials including women undergoing vaginal delivery who received prophylactic oxytocin during management of the third stage of labour. Primary outcomes were blood loss 500 mL or more after delivery, need for additional uterotonics, and maternal all-cause mortality. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion, extracted data, and assessed trial quality. Data were checked for accuracy. We assessed the quality of the evidence using the GRADE approach. MAIN RESULTS: This review includes 24 trials, with 23 trials involving 10,018 women contributing data. Due to many trials assessed at high risk of bias, evidence grade ranged from very low to moderate quality.Prophylactic oxytocin versus no uterotonics or placebo (nine trials)Prophylactic oxytocin compared with no uterotonics or placebo may reduce the risk of blood loss of 500 mL after delivery (average risk ratio (RR) 0.51, 95% confidence interval (C) 0.37 to 0.72; 4162 women; 6 studies; Tau² = 0.10, I² = 75%; low-quality evidence), and blood loss 1000 mL after delivery (RR 0.59, 95% CI 0.42 to 0.83; 4123 women; 5 studies; low-quality evidence). Prophylactic oxytocin probably reduces the need for additional uterotonics (average RR 0.54, 95% CI 0.36 to 0.80; 3135 women; 4 studies; Tau² = 0.07, I² = 44%; moderate-quality evidence). There may be no difference in the risk of needing a blood transfusion in women receiving oxytocin compared to no uterotonics or placebo (RR 0.88, 95% CI 0.44 to 1.78; 3081 women; 3 studies; low-quality evidence). Oxytocin may be associated with an increased risk of a third stage greater than 30 minutes (RR 2.55, 95% CI 0.88 to 7.44; 1947 women; 1 study; moderate-quality evidence), however the confidence interval is wide and includes 1.0, indicating that there may be little or no difference.Prophylactic oxytocin versus ergot alkaloids (15 trials)It is uncertain whether oxytocin reduces the likelihood of blood loss 500 mL (average RR 0.84, 95% CI 0.56 to 1.25; 3082 women; 10 studies; Tau² = 0.14, I² = 49%; very low-quality evidence) or the need for additional uterotonics compared to ergot alkaloids (average RR 0.89, 95% CI 0.43 to 1.81; 2178 women; 8 studies; Tau² = 0.76, I² = 79%; very low-quality evidence), because the quality of this evidence is very low. The quality of evidence was very low for blood loss of 1000 mL (RR 1.13, 95% CI 0.63 to 2.01; 1577 women; 3 studies; very low-quality evidence), and need for blood transfusion (average RR 1.37, 95% CI 0.34 to 5.51; 1578 women; 7 studies; Tau² = 1.34, I² = 45%; very low-quality evidence), making benefit of oxytocin over ergot alkaloids uncertain. Oxytocin probably increases the risk of a prolonged third stage greater than 30 minutes (RR 4.69, 95% CI 1.63 to 13.45; 450 women; 2 studies; moderate-quality evidence), although it is uncertain if this translates into increased risk of manual placental removal (average RR 1.10, 95% CI 0.39 to 3.10; 3127 women; 8 studies; Tau² = 1.07, I² = 76%; very low-quality evidence). Oxytocin may make little or no difference to risk of diastolic blood pressure > 100 mm Hg (average RR 0.28, 95% CI 0.04 to 2.05; 960 women; 3 studies; Tau² = 1.23, I² = 50%; low-quality evidence), and is probably associated with a lower risk of vomiting (RR 0.09, 95% CI 0.05 to 0.14; 1991 women; 7 studies; moderate-quality evidence), although the impact of oxytocin on headaches is uncertain (average RR 0.19, 95% CI 0.03 to 1.02; 1543 women; 5 studies; Tau² = 2.54, I² = 72%; very low-quality evidence).Prophylactic oxytocin-ergometrine versus ergot alkaloids (four trials)Oxytocin-ergometrine may slightly reduce the risk of blood loss greater than 500 mL after delivery compared to ergot alkaloids (RR 0.44, 95% CI 0.20 to 0.94; 1168 women; 3 studies; low-quality evidence), based on outcomes from quasi-randomised trials with a high risk of bias. There were no maternal deaths reported in either treatment group in the one trial that reported this outcome (RR not estimable; 1 trial, 807 women; moderate-quality evidence). Need for additional uterotonics was not reported.No subgroup differences were observed between active or expectant management, or different routes or doses of oxytocin for any of our comparisons. AUTHORS' CONCLUSIONS: Prophylactic oxytocin compared with no uterotonics may reduce blood loss and the need for additional uterotonics. The effect of oxytocin compared to ergot alkaloids is uncertain with regards to blood loss, need for additional uterotonics, and blood transfusion. Oxytocin may increase the risk of a prolonged third stage compared to ergot alkaloids, although whether this translates into increased risk of manual placental removal is uncertain. This potential risk must be weighed against the possible increased risk of side effects associated with ergot alkaloids. Oxytocin-ergometrine may reduce blood loss compared to ergot alkaloids, however the certainty of this conclusion is low. More high-quality trials are needed to assess optimal dosing and route of oxytocin administration, with inclusion of important outcomes such as maternal mortality, shock, and transfer to a higher level of care. A network meta-analysis of uterotonics for PPH prevention plans to address issues around optimal dosing and routes of oxytocin and other uterotonics.

Risk of Ischemic Placental Disease in Relation to Family History of Preeclampsia.

OBJECTIVE: To assess the risk of ischemic placental disease (IPD) including preeclampsia, small for gestational age (SGA), and abruption, in relation to preeclampsia in maternal grandmother, mother, and sister(s). STUDY DESIGN: We performed a secondary analysis of data from a randomized trial of vitamins C and E for preeclampsia prevention. Data on family history of preeclampsia were based on recall by the proband. The associations between family history of preeclampsia and the odds of IPD were evaluated from alternating logistic regressions. RESULTS: Of the 9,686 women who delivered nonmalformed, singleton live births, 17.1% had IPD. Probands provided data on preeclampsia in 55.5% (n = 5,374) on all three family members, 26.5% (n = 2,562) in mother and sister(s) only, and 11.6% (n = 1,125) in sister(s) only. The pairwise odds ratio (pOR) of IPD was 1.16 (95% confidence interval [CI]: 1.00-1.36) if one or more of the female relatives had preeclampsia. The pORs of preeclampsia were 1.54 (95% CI: 1.12-2.13) and 1.35 (95% CI: 1.03-1.77) if the proband's mother or sister(s) had a preeclamptic pregnancy, respectively, but no associations were seen for SGA infant or abruption. CONCLUSION: This study suggests that IPD may share a predisposition with preeclampsia, suggesting a familial inheritance.

Defining failed induction of labor.

BACKGROUND: While there are well-accepted standards for the diagnosis of arrested active-phase labor, the definition of a "failed" induction of labor remains less certain. One approach to diagnosing a failed induction is based on the duration of the latent phase. However, a standard for the minimum duration that the latent phase of a labor induction should continue, absent acute maternal or fetal indications for cesarean delivery, remains lacking. OBJECTIVE: The objective of this study was to determine the frequency of adverse maternal and perinatal outcomes as a function of the duration of the latent phase among nulliparous women undergoing labor induction. STUDY DESIGN: This study is based on data from an obstetric cohort of women delivering at 25 US hospitals from 2008 through 2011. Nulliparous women who had a term singleton gestation in the cephalic presentation were eligible for this analysis if they underwent a labor induction. Consistent with prior studies, the latent phase was determined to begin once cervical ripening had ended, oxytocin was initiated, and rupture of membranes had occurred, and was determined to end once 5-cm dilation was achieved. The frequencies of cesarean delivery, as well as of adverse maternal (eg, postpartum hemorrhage, chorioamnionitis) and perinatal (eg, a composite frequency of seizures, sepsis, bone or nerve injury, encephalopathy, or death) outcomes, were compared as a function of the duration of the latent phase (analyzed with time both as a continuous measure and categorized in 3-hour increments). RESULTS: A total of 10,677 women were available for analysis. In the vast majority (96.4%) of women, the active phase had been reached by 15 hours. The longer the duration of a woman's latent phase, the greater her chance of ultimately undergoing a cesarean delivery (P < .001, for time both as a continuous and categorical independent variable), although >40% of women whose latent phase lasted ≥18 hours still had a vaginal delivery. Several maternal morbidities, such as postpartum hemorrhage (P < .001) and chorioamnionitis (P < .001), increased in frequency as the length of latent phase increased. Conversely, the frequencies of most adverse perinatal outcomes were statistically stable over time. CONCLUSION: The large majority of women undergoing labor induction will have entered the active phase by 15 hours after oxytocin has started and rupture of membranes has occurred. Maternal adverse outcomes become statistically more frequent with greater time in the latent phase, although the absolute increase in frequency is relatively small. These data suggest that cesarean delivery should not be undertaken during the latent phase prior to at least 15 hours after oxytocin and rupture of membranes have occurred. The decision to continue labor beyond this point should be individualized, and may take into account factors such as other evidence of labor progress.