New labor curves of dilation and station to improve the accuracy of predicting labor progress.

BACKGROUND: The diagnosis of failure to progress, the most common indication for intrapartum cesarean delivery, is based on the assessment of cervical dilation and station over time. Labor curves serve as references for expected changes in dilation and fetal descent. The labor curves of Friedman, Zhang et al, and others are based on time alone and derived from mothers with spontaneous labor onset. However, labor induction is now common, and clinicians also consider other factors when assessing labor progress. Labor curves that consider the use of labor induction and other factors that influence labor progress have the potential to be more accurate and closer to clinical decision-making. OBJECTIVE: This study aimed to compare the prediction errors of labor curves based on a single factor (time) or multiple clinically relevant factors using two modeling methods: mixed-effects regression, a standard statistical method, and Gaussian processes, a machine learning method. STUDY DESIGN: This was a longitudinal cohort study of changes in dilation and station based on data from 8022 births in nulliparous women with a live, singleton, vertex-presenting fetus ≥35 weeks of gestation with a vaginal delivery. New labor curves of dilation and station were generated with 10-fold cross-validation. External validation was performed using a geographically independent group. Model variables included time from the first examination in the 20 hours before delivery; dilation, effacement, and station recorded at the previous examination; cumulative contraction counts; and use of epidural anesthesia and labor induction. To assess model accuracy, differences between each model's predicted value and its corresponding observed value were calculated. These prediction errors were summarized using mean absolute error and root mean squared error statistics. RESULTS: Dilation curves based on multiple parameters were more accurate than those derived from time alone. The mean absolute error of the multifactor methods was better (lower) than those of the single-factor methods (0.826 cm [95% confidence interval, 0.820-0.832] for the multifactor machine learning and 0.893 cm [95% confidence interval, 0.885-0.901] for the multifactor mixed-effects method and 2.122 cm [95% confidence interval, 2.108-2.136] for the single-factor methods; P<.0001 for both comparisons). The root mean squared errors of the multifactor methods were also better (lower) than those of the single-factor methods (1.126 cm [95% confidence interval, 1.118-1.133] for the machine learning [P<.0001] and 1.172 cm [95% confidence interval, 1.164-1.181] for the mixed-effects methods and 2.504 cm [95% confidence interval, 2.487-2.521] for the single-factor [P<.0001 for both comparisons]). The multifactor machine learning dilation models showed small but statistically significant improvements in accuracy compared to the mixed-effects regression models (P<.0001). The multifactor machine learning method produced a curve of descent with a mean absolute error of 0.512 cm (95% confidence interval, 0.509-0.515) and a root mean squared error of 0.660 cm (95% confidence interval, 0.655-0.666). External validation using independent data produced similar findings. CONCLUSION: Cervical dilation models based on multiple clinically relevant parameters showed improved (lower) prediction errors compared to models based on time alone. The mean prediction errors were reduced by more than 50%. A more accurate assessment of departure from expected dilation and station may help clinicians optimize intrapartum management.

The Association of Race and Ethnicity with Severe Maternal Morbidity among Individuals Diagnosed with Hypertensive Disorders of Pregnancy.

OBJECTIVE: This study aimed to examine whether there are racial disparities in severe maternal morbidity (SMM) in patients with hypertensive disorders of pregnancy (HDP). STUDY DESIGN: Secondary analysis of an observational study of 115,502 patients who had a live birth at ≥20 weeks in 25 hospitals in the United States from 2008 to 2011. Only patients with HDP were included in this analysis. Race and ethnicity were categorized as non-Hispanic White, non-Hispanic Black (NHB), and Hispanic and were abstracted from the medical charts. Patients of other races and ethnicities were excluded. Associations were estimated between race and ethnicity, and the primary outcome of SMM, defined as any of the following, was estimated by unadjusted logistic and multivariable backward logistic regressions: blood transfusion ≥4 units, unexpected surgical procedure, need for a ventilator ≥12 hours, intensive care unit (ICU) admission, or failure of ≥1 organ system. Multivariable models were run classifying HDP into three levels as follows: (1) gestational hypertension; (2) preeclampsia (mild, severe, or superimposed); and (3) eclampsia or HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome. RESULTS: A total of 9,612 individuals with HDP met inclusion criteria. No maternal deaths occurred in this cohort. In univariable analysis, non-Hispanic White patients were more likely to present with gestational hypertension whereas NHB and Hispanic patients were more likely to present with preeclampsia. The frequency of the primary outcome, composite SMM, was higher in NHB patients compared with that in non-Hispanic White or Hispanic patients (11.8 vs. 4.5% in non-Hispanic White and 4.8% in Hispanic, p < 0.001). This difference was driven by a higher frequency of blood transfusions and ICU admissions among NHB individuals. Prior to adjusting the analysis for confounding factors, the odds ratio (OR) of primary composite outcomes in NHB individuals was 2.85 (95% confidence interval [CI]: 2.38, 3.42) compared with non-Hispanic White. After adjusting for sociodemographic and clinical factors, hospital site, and the severity of HDP, the OR of composite SMM did not differ between the groups (adjusted OR [aOR] = 1.26, 95% CI: 0.95, 1.67 for NHB, and aOR = 1.29, 95% CI: 0.94, 1.77 for Hispanic, compared with non-Hispanic White patients). Sensitivity analysis was done to exclude one single site that was an outliner with the highest ICU admissions and demonstrated no difference in ICU admission by maternal race and ethnicity. CONCLUSION: NHB patients with HDP had higher rates of the composite SMM compared with non-Hispanic White patients, driven mainly by a higher frequency of blood transfusions and ICU admissions. However, once severity and other confounding factors were taken into account, the differences did not persist. KEY POINTS: · Black patients with HDP had higher frequency of SMM compared with non-Hispanic White patients.. · The SMM disparities were driven by blood transfusions and ICU admissions.. · After adjustment for confounders, including HDP severity, the significant difference in SMM did not persist..

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..

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..

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.

Infectious Hepatitis in Pregnancy.

Infectious hepatitis in pregnancy is clinically significant in both the acute and chronic phases. Here, we review the perinatal implications of chronic hepatitis B and C and acute hepatitis A and E. Familiarity with screening, transmission, diagnosis, and management of infectious hepatitis is of ongoing importance during obstetric care, as these diseases are endemic in much of the world. Pregnancy and interpregnancy care provide opportunities to prevent infection and transmission of hepatitis.

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.

Influence of IFNL3 and HLA-DPB1 genotype on postpartum control of hepatitis C virus replication and T-cell recovery.

Chronic hepatitis C virus (HCV) infection is characterized by exhaustion of virus-specific T-cells and stable viremia. Pregnancy is an exception. Viremia gradually climbs during gestation but sometimes declines sharply in the months following delivery. Here, we demonstrated that postpartum HCV control was associated with enhanced virus-specific T-cell immunity. Women with viral load declines of at least 1 log10 between the third trimester and 3-mo postpartum exhibited HCV-specific T-cell responses of greater breadth (P = 0.0052) and magnitude (P = 0.026) at 3-mo postpartum than women who failed to control viremia. Moreover, viral dynamics were consistent in women after consecutive pregnancies, suggesting genetic underpinnings. We therefore searched for genetic associations with human leukocyte antigen (HLA) alleles and IFN-λ3 gene (IFNL3) polymorphisms that influence HCV infection outcome. Postpartum viral control was associated with the IFNL3 rs12979860 genotype CC (P = 0.045 at 6 mo) that predicts a positive response to IFN-based therapy. Suppression of virus replication after pregnancy was also strongly influenced by the HLA class II DPB1 locus. HLA-DPB1 alleles are classified by high and low patterns of expression. Carriage of at least one high-expression HLA-DPB1 allele predicted resurgent virus-specific T-cell immunity and viral control at 3-mo postpartum (P = 0.0002). When considered together in multivariable analysis, IFNL3 and HLA-DPB1 independently affected viral control at 3- and 6-mo postpartum. Together, these findings support a model where spontaneous control of HCV such as sometimes follows pregnancy is governed by genetic polymorphisms that affect type III IFN signaling and virus-specific cellular immune responses.

Prolonged activation of innate antiviral gene signature after childbirth is determined by IFNL3 genotype.

Maternal innate and adaptive immune responses are modulated during pregnancy to concurrently defend against infection and tolerate the semiallogeneic fetus. The restoration of these systems after childbirth is poorly understood. We reasoned that enhanced innate immune activation may extend beyond gestation while adaptive immunity recovers. To test this hypothesis, the transcriptional profiles of total peripheral blood mononuclear cells following delivery in healthy women were compared with those of nonpregnant control subjects. Interestingly, interferon-stimulated genes (ISGs) encoding proteins such as IFIT1, IFIT2, and IFIT3, as well as signaling proteins such as STAT1, STAT2, and MAVS, were enriched postpartum. Antiviral genes were primarily expressed in CD14(+) cells and could be stratified according to genetic variation at the interferon-λ3 gene (IFNL3, also named IL28B) SNP rs12979860. Antiviral gene expression was sustained beyond 6 mo following delivery in mothers with a CT or TT genotype, but resembled baseline nonpregnant control levels following delivery in mothers with a CC genotype. CT and TT IFNL3 genotypes have been associated with persistent elevated ISG expression in individuals chronically infected with hepatitis C virus. Together, these data suggest that postpartum, the normalization of the physiological rheostat controlling IFN signaling depends on IFNL3 genotype.

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.

Enhanced identification of maternal hepatitis C virus infection using existing public health surveillance systems.

BACKGROUND: Hepatitis C virus (HCV) infection is under-recognized among US adults and children. Prenatal HCV screening may help close the diagnosis gap among women while also identifying at-risk infants. Current surveillance efforts for maternal HCV rely primarily on birth certificate data. We sought a more accurate assessment of HCV prevalence among pregnant women in Ohio by combining existing public health surveillance data. METHODS: Vital Statistics (VS) birth certificate data and Ohio Disease Reporting System (ODRS) HCV case data, both available through the Ohio Department of Health, were linked to determine rates of past or present HCV infection among women giving birth from 2012 to 2015 in Ohio, overall and by county. Among women with available test results, the proportion with present HCV infection indicated by detectable viraemia during pregnancy was calculated. RESULTS: Birth certificate data identified 4695 deliveries to women with past/present HCV infection during the study period. Linkage to ODRS revealed an additional 1778 deliveries to women with past/present infection, including 355 with confirmed viraemia during pregnancy. The prevalence of past/present HCV among pregnant women in Ohio rose from 0.82% in 2012 to 1.54% in 2015. CONCLUSIONS: Maternal HCV infection is under-recognized and increasing in prevalence. Current case identification processes are inadequate in pregnancy, even among women with prior positive HCV testing. Alternative approaches, including enhanced risk factor-based screening or universal prenatal screening in high prevalence settings, are needed to improve rates of HCV recognition among reproductive-aged women and newborns at risk of vertical transmission.

The Association of Decision-to-Incision Time for Cesarean Delivery with Maternal and Neonatal Outcomes.

OBJECTIVE: The objective of this study was to estimate whether the decision-to-incision (DTI) time for cesarean delivery (CD) is associated with differences in maternal and neonatal outcomes. METHODS: This analysis is of data from women at 25 U.S. medical centers with a term, singleton, cephalic nonanomalous gestation and no prior CD, who underwent an intrapartum CD. Perinatal and maternal outcomes associated with DTI intervals of ≤ 15, 16 to 30, and > 30 minutes were compared. RESULTS: Among 3,482 eligible women, median DTI times were 46 and 27 minutes for arrest and fetal indications for CD, respectively (p < 0.01). Women with a fetal indication whose DTI interval was > 30 minutes had similar odds to the referent group (DTI of 16-30 minutes) for the adverse neonatal and maternal composites (odds ratio [OR]: 0.83, 95% confidence interval [CI]: 0.40-1.71 and OR: 0.89, 95% CI: 0.63-1.27). For arrest disorders, the odds of the adverse neonatal composite were lower among women with a DTI of > 30 minutes (OR: 0.25, 95% CI: 0.08-0.77), and the adverse maternal composite was no different (OR: 1.15, 95% CI: 0.81-1.63). CONCLUSION: In this analysis, DTI times longer than 30 minutes were not associated with worse maternal or neonatal outcomes.

Intravenous drug use is associated with alloimmunization in pregnancy.

BACKGROUND: Anecdotal evidence has suggested an association of intravenous drug abuse with alloimmunization; however, published data are limited to case reports. OBJECTIVE: The purpose of this study was to determine whether women with a history of intravenous drug abuse have an increased risk of alloimmunization. STUDY DESIGN: A retrospective cohort study was performed with the use of data from a single-center blood bank and perinatal database from 2008-2014. Blood bank data were used to identify women with alloimmunization, which was defined as a positive antibody screen in pregnancy not due to naturally occurring antibodies, agglutinins, autoantibodies, or Rh immunoglobulin administration. Intravenous drug abuse was ascertained from a comprehensive database that has captured all drug abuse in pregnancy since 2008. For women who contributed >1 pregnancy to the database, only the most recent pregnancy was included. The rates of alloimmunization among women with a history of intravenous drug abuse and general obstetric populations were calculated and compared. The distribution of alloantibody types, proportion of Rh-group alloantibodies, and patient Rh status were assessed for intravenous and non-intravenous drug abuse-associated alloimmunization. Characteristics and outcomes between intravenous and non-intravenous drug abuse-associated alloimmunization were assessed for women with clinically significant alloantibodies. RESULTS: Alloimmunization was more common in women with a history of intravenous drug abuse (11/305 women; 3.6%) compared to women without a history of intravenous drug abuse (288/16,022 women; 1.8%; relative risk, 2.00; 95% confidence interval, 1.11-3.62). Needle-sharing was present in 7 and suspected in 4 women with an intravenous drug abuse history. Among women with a history of intravenous drug abuse, none had a history of transfusion or traditional risk factor for alloimmunization. The distribution of alloantibodies was different between intravenous drug abuse- and non-intravenous drug abuse-associated alloimmunization. Rh group alloantibodies and Rh-negative status were more common in women with a history of intravenous drug abuse. Among Rh-negative women with a history of intravenous drug abuse, 50% of RhD alloimmunization cases occurred in nulliparous women. The rate of multiple alloantibodies was not different between intravenous drug abuse- and non-intravenous drug abuse-associated alloimmunization. CONCLUSION: Maternal history of intravenous drug abuse is associated with an increased risk of alloimmunization. Approximately 1 in 30 intravenous drug abuse women may be diagnosed with an alloantibody in pregnancy. Given the current US opioid epidemic, increased vigilance in screening is required. Needle-sharing represents a possible mechanism for intravenous drug abuse-associated alloimmunization; however, limited obstetric care, failure to obtain Rh immunoglobulin, or failure to identify early pregnancy loss cannot be excluded.

Preterm neonatal morbidity and mortality by gestational age: a contemporary cohort.

BACKGROUND: Although preterm birth <37 weeks' gestation is the leading cause of neonatal morbidity and mortality in the United States, the majority of data regarding preterm neonatal outcomes come from older studies, and many reports have been limited to only very preterm neonates. Delineation of neonatal outcomes by delivery gestational age is needed to further clarify the continuum of mortality and morbidity frequencies among preterm neonates. OBJECTIVE: We sought to describe the contemporary frequencies of neonatal death, neonatal morbidities, and neonatal length of stay across the spectrum of preterm gestational ages. STUDY DESIGN: This was a secondary analysis of an obstetric cohort of 115,502 women and their neonates who were born in 25 hospitals nationwide, 2008 through 2011. All liveborn nonanomalous singleton preterm (23.0-36.9 weeks of gestation) neonates were included in this analysis. The frequency of neonatal death, major neonatal morbidity (intraventricular hemorrhage grade III/IV, seizures, hypoxic-ischemic encephalopathy, necrotizing enterocolitis stage II/III, bronchopulmonary dysplasia, persistent pulmonary hypertension), and minor neonatal morbidity (hypotension requiring treatment, intraventricular hemorrhage grade I/II, necrotizing enterocolitis stage I, respiratory distress syndrome, hyperbilirubinemia requiring treatment) were calculated by delivery gestational age; each neonate was classified once by the worst outcome for which criteria was met. RESULTS: In all, 8334 deliveries met inclusion criteria. There were 119 (1.4%) neonatal deaths. In all, 657 (7.9%) neonates had major morbidity, 3136 (37.6%) had minor morbidity, and 4422 (53.1%) survived without any of the studied morbidities. Deaths declined rapidly with each advancing week of gestation. This decline in death was accompanied by an increase in major neonatal morbidity, which peaked at 54.8% at 25 weeks of gestation. As frequencies of death and major neonatal morbidity fell, minor neonatal morbidity increased, peaking at 81.7% at 31 weeks of gestation. The frequency of all morbidities fell >32 weeks. After 25 weeks, neonatal length of hospital stay decreased significantly with each additional completed week of pregnancy; among babies delivered from 26-32 weeks of gestation, each additional week in utero reduced the subsequent length of neonatal hospitalization by a minimum of 8 days. The median postmenstrual age at discharge nadired around 36 weeks' postmenstrual age for babies born at 31-35 weeks of gestation. CONCLUSION: Our data show that there is a continuum of outcomes, with each additional week of gestation conferring survival benefit while reducing the length of initial hospitalization. These contemporary data can be useful for patient counseling regarding preterm outcomes.

Serious maternal complications after early preterm delivery (24-33 weeks' gestation).

OBJECTIVE: We sought to describe the prevalence of serious maternal complications following early preterm birth by gestational age (GA), delivery route, and type of cesarean incision. STUDY DESIGN: Trained personnel abstracted data from maternal and neonatal charts for all deliveries on randomly selected days representing one third of deliveries across 25 US hospitals over 3 years (n = 115,502). All women delivering nonanomalous singletons between 23-33 weeks' gestation were included. Women were excluded for antepartum stillbirth and highly morbid conditions for which route of delivery would not likely impact morbidity including nonreassuring fetal status, cord prolapse, placenta previa, placenta accreta, placental abruption, and severe and unstable maternal conditions (cardiopulmonary collapse, acute respiratory distress syndrome, seizures). Serious maternal complications were defined as: hemorrhage (blood loss ≥1500 mL, blood transfusion, or hysterectomy for hemorrhage), infection (endometritis, wound dehiscence, or wound infection requiring antibiotics, reopening, or unexpected procedure), intensive care unit admission, or death. Delivery route was categorized as classic cesarean delivery (CCD), low transverse cesarean delivery (LTCD), low vertical cesarean delivery (LVCD), and vaginal delivery. Association of delivery route with complications was estimated using multivariable regression models yielding adjusted relative risks (aRR) controlling for maternal age, race, body mass index, hypertension, diabetes, preterm premature rupture of membranes, preterm labor, GA, and hospital of delivery. RESULTS: Of 2659 women who met criteria for inclusion in this analysis, 8.6% of women experienced serious maternal complications. Complications were associated with GA and were highest between 23-27 weeks of gestation. The frequency of complications was associated with delivery route; compared with 3.5% of vaginal delivery, 23.0% of CCD (aRR, 3.54; 95% confidence interval (CI), 2.29-5.48), 12.1% of LTCD (aRR, 2.59; 95% CI, 1.77-3.77), and 10.3% of LVCD (aRR, 2.27; 95% CI, 0.68-7.55) experienced complications. There was no significant difference in complication rates between CCD and LTCD (aRR, 1.37; 95% CI, 0.95-1.97) or between CCD and LVCD (aRR, 1.56; 95% CI, 0.48-5.07). CONCLUSION: The risk of maternal complications after early preterm delivery is substantial, particularly in women who undergo cesarean delivery. Obstetricians need to be prepared to manage potential hemorrhage, infection, and intensive care unit admission for early preterm births requiring cesarean delivery.