Factors Associated with Maternal Morbidity among Black Women in the United States.

OBJECTIVE: Non-Hispanic Black people (NHBP) have a three-fold higher rate of maternal mortality compared to other racial groups. Racial disparities in maternal morbidity are well-described; however, there are substantial differences in cultural, economic, and social determinants of health among racial groups. We thus sought to study the at-risk, non-Hispanic Black population as its own cohort to identify factors most associated with severe maternal morbidity (SMM). STUDY DESIGN: This is a population-based retrospective case-control study of all live births in the United States between 2017 and 2019 using birth records obtained from the National Center for Health Statistics. The primary outcome for this study was to determine demographic, social, medical, and obstetric factors associated with maternal morbidity among NHBP who did and did not experience an SMM event. Multivariable logistic regression was used to estimate the adjusted odds ratio between each individual factor and the outcome of SMM among NHBP. RESULTS: Of the 1,624,744 NHBP who delivered between 2017 and 2019, 1.1% experienced an SMM event defined as a composite of blood product transfusion, eclamptic seizure, intensive care unit admission, unplanned hysterectomy, and uterine rupture. The rates of these individual SMM events per 10,000 deliveries were 50, 40, 20, 5, and 4 among NHBP, respectively. Among NHBP, factors associated in multivariable regression analysis with SMM in order of strength of association included cesarean delivery, earlier gestational age at delivery, preeclampsia, induction of labor, chronic hypertension, prior preterm birth, lower educational attainment, multifetal gestation, advanced maternal age, pregestational diabetes, and cigarette smoking. The population attributable fraction for cesarean delivery, preterm birth, and pregnancy-induced hypertensive disease for the outcome of SMM were 0.46, 0.23, and 0.07, respectively. CONCLUSION: The three factors most associated with SMM among NHBP are potentially avoidable or modifiable by aggressive screening, prevention, and treatment of preeclampsia and preterm birth as well as reducing cesarean rates in this population. KEY POINTS: · The rate of SMM in NHBP may be modifiable.. · NHBP have a three-fold higher rate of maternal mortality.. · Preeclampsia, preterm birth, and cesarean sections are most associated with maternal morbidity..

Comparison of the Scope of Practice of the Army Combat Medic Specialist and Civilian National EMS Certification Levels.

INTRODUCTION: The transition of Army Combat Medic Specialists (Military Occupational Specialty Code: 68W) from military to civilian emergency medical services (EMS) is challenging, and the pathway is not clearly defined. Our objective was to evaluate the current military requirements for 68W and how they compare to the 2019 EMS National Scope of Practice Model (SoPM) for the civilian emergency medical technician (EMT) and advanced emergency medical technician (AEMT). METHODS: This was a cross-sectional evaluation of the 68W skill floor as defined by the Soldier's Manual and Trainer's Guide Healthcare Specialist and Medical Education and Demonstration of Individual Competence in comparison to the 2019 SoPM, which categorizes EMS tasks into seven skill categories. Military training documents were reviewed and extracted for specific information on military scope of practice and task-specific training requirements. Descriptive statistics were calculated. RESULTS: Army 68Ws were noted to perform all (59/59) tasks that coincide with the EMT SoPM. Further, Army 68W practiced above scope in the following skill categories: airway/ventilation (3 tasks); medication administration route (7 tasks); medical director approved medication (6 tasks); intravenous initiation maintenance fluids (4 tasks); and miscellaneous (1 task). Army 68W perform 96% (74/77) of tasks aligned with the AEMT SoPM, excluding tracheobronchial suctioning of an intubated patient, end-tidal CO2 monitoring or waveform capnography, and inhaled nitrous oxide monitoring. Additionally, the 68W scope included six tasks that were above the SoPM for AEMT; airway/ventilation (2 tasks); medication administration route (2 tasks); and medical director approved medication (2 tasks). CONCLUSIONS: The scope of practice of U.S. Army 68W Combat Medics aligns well with the civilian 2019 Scope of Practice Model for EMTs and AEMTs. Based on the comparative scope of practice analysis, transitioning from Army 68W Combat Medic to civilian AEMT would require minimal additional training. This represents a promising potential workforce to assist with EMS workforce challenges. Although aligning the scope of practice is a promising first step, future research is needed to assess the relationship of Army 68Ws training with state licensure and certification equivalency to facilitate this transition.

A functional mechanism for a non-coding variant near AGTR2 associated with risk for preterm birth.

BACKGROUND: Preterm birth (PTB), defined as delivery before 37 gestational weeks, imposes significant public health burdens. A recent maternal genome-wide association study of spontaneous PTB identified a noncoding locus near the angiotensin II receptor type 2 (AGTR2) gene. Genotype-Tissue Expression data revealed that alleles associated with decreased AGTR2 expression in the uterus were linked to an increased risk of PTB and shortened gestational duration. We hypothesized that a causative variant in this locus modifies AGTR2 expression by altering transcription factor (TF) binding. METHODS: To investigate this hypothesis, we performed bioinformatics analyses and functional characterizations at the implicated locus. Potential causal single nucleotide polymorphisms (SNPs) were prioritized, and allele-dependent binding of TFs was predicted. Reporter assays were employed to assess the enhancer activity of the top PTB-associated non-coding variant, rs7889204, and its impact on TF binding. RESULTS: Our analyses revealed that rs7889204, a top PTB-associated non-coding genetic variant is one of the strongest eQTLs for the AGTR2 gene in uterine tissue samples. We observed differential binding of CEBPB (CCAAT enhancer binding protein beta) and HOXA10 (homeobox A10) to the alleles of rs7889204. Reporter assays demonstrated decreased enhancer activity for the rs7889204 risk "C" allele. CONCLUSION: Collectively, these results demonstrate that decreased AGTR2 expression caused by reduced transcription factor binding increases the risk for PTB and suggest that enhancing AGTR2 activity may be a preventative measure in reducing PTB risk.

Association of Antenatal Corticosteroid Exposure and Infant Survival at 22 and 23 Weeks.

OBJECTIVE: In 2014, the leading obstetric societies published an executive summary of a joint workshop to establish obstetric interventions to be considered for periviable births. Antenatal corticosteroid administration between 220/7 and 226/7 weeks was not recommended given existing evidence. We sought to evaluate whether antenatal steroid exposure was associated with improved survival among resuscitated newborns delivered between 22 and 23 weeks of gestation. STUDY DESIGN: We conducted a population-based cohort study of all resuscitated livebirths delivered between 220/7 and 236/7 weeks of gestation in the United States during 2009 to 2014 utilizing National Center for Health Statistics data. The primary outcome was rate of survival to 1 year of life (YOL) between infant cohorts based on antenatal steroid exposure. Multivariable logistic regression estimated the association of antenatal steroid exposure on survival outcomes. RESULTS: In the United States between 2009 and 2014, there were 2,635 and 7,992 infants who received postnatal resuscitation after delivery between 220/7 to 226/7 and 230/7 to 236/7 weeks of gestation, respectively. Few infants born at 22 (15.9%) and 23 (26.0%) weeks of gestation received antenatal corticosteroids (ANCS). Among resuscitated neonates, survival to 1 YOL was 45.2 versus 27.8% (adjusted relative risk [aRR]: 1.6, 95% confidence interval [CI]: 1.2-2.1) and 57.9 versus 47.7% (aRR: 1.3, 95% CI: 1.1-1.5) for infants exposed to ANCS compared with those not exposed at 22 and 23 weeks of gestation, respectively. When stratified by 100 g birth weight category, ANCS were associated with survival among neonates weighing 500 to 599 g (aRR: 1.9, 95% CI: 1.3-2.9) and 600 to 699 g (aRR: 1.7, 95% CI: 1.1-2.6) at 22 weeks. CONCLUSION: Exposure to ANCS was associated with higher survival rates to 1 YOL among resuscitated infants born at 22 and 23 weeks. National guidelines recommending against ANCS utilization at 22 weeks should be re-evaluated given emerging evidence of benefit. KEY POINTS: · Exposure to antenatal steroids was associated with higher survival rates at 22 and 23 weeks of gestation.. · Women exposed to antenatal steroids were more likely to have an adverse outcome.. · The association between steroids and survival was observed among infants with birth weights > 500 g..

Factors Associated with Receiving No Maternal or Neonatal Interventions among Periviable Deliveries.

OBJECTIVE: The aim of this study was to quantify the influence of maternal sociodemographic, medical, and pregnancy characteristics on not receiving maternal and neonatal interventions with deliveries occurring at 22 to 23 weeks of gestation. STUDY DESIGN: This was a case-control study of U.S. live births at 220/6 to 236/7 weeks of gestation using vital statistics birth records from 2012 to 2016. We analyzed births that received no interventions for periviable delivery. Births were defined as having no interventions if they did not receive maternal (cesarean delivery, maternal hospital transfer, or antenatal corticosteroid administration) or neonatal interventions (neonatal intensive care unit admission, surfactant administration, antibiotic administration, or assisted ventilation). Logistic regression estimated the influence of maternal and pregnancy factors on the receipt of no interventions when delivery occurred at 22 to 23 weeks. RESULTS: Of 19,844,580 U.S. live births in 2012-2016, 24,379 (0.12%) occurred at 22 to 23 weeks; 54.3% of 22-week deliveries and 15.7% of 23-week deliveries received no interventions. Non-Hispanic Black maternal race was associated with no maternal interventions at 22 and 23 weeks. Private insurance, singleton pregnancy, and small for gestational age were associated with receiving no neonatal interventions at 22 and 23 weeks of gestation. CONCLUSIONS: Withholding or refusing maternal and neonatal interventions occurs frequently at the threshold of viability. Our data highlight various sociodemographic, pregnancy, and medical factors associated with decisions to not offer or receive maternal or neonatal interventions when birth occurs at the threshold of viability. The data elucidate observed practices and may assist in the development of further research. KEY POINTS: · Non-Hispanic Black race was associated with receiving no maternal interventions.. · Indicators of high socioeconomic status were associated with no neonatal inventions.. · Patient-level factors influence the receipt of no interventions for periviable birth..

Factors Associated with Occurrence of Stillbirth before 32 Weeks of Gestation in a Contemporary Cohort.

OBJECTIVE: We sought to quantify the distribution of stillbirths by gestational age (GA) in a contemporary cohort and to determine identifiable risk factors associated with stillbirth prior to 32 weeks of gestation. STUDY DESIGN: Population-based case-control study of all stillbirths in the United States during the year 2014, utilizing vital statistics data, obtained from the National Center for Health Statistics. Distribution of stillbirths were stratified by 20 to 44 weeks of GA, in women diagnosed with stillbirth in the antepartum period. Pregnancy characteristics were compared between those diagnosed with stillbirth <32 versus ≥32 weeks of gestation. Multivariate logistic regression estimated the relative influence of various factors on the outcome of stillbirth prior to 32 weeks of gestation. RESULTS: There were 15,998 nonlaboring women diagnosed with stillbirth during 2014 in the United States between 20 and 44 weeks. Of them, 60.1% (n = 9,618) occurred before antenatal fetal surveillance (ANFS) is typically initiated (<32 weeks) and 39.9% (n = 6,380) were diagnosed at ≥32 weeks. Women with stillbirth prior to 32 weeks were more likely to be of non-Hispanic Black race (29.0 vs. 23.9%, p < 0.001), nulliparous (53.8 vs. 50.6%, p = 0.001), have chronic hypertension (CHTN; 6.0 vs. 4.3%, p < 0.001), and fetal growth restriction as evidenced by small for GA (SGA < 10th%) birth weight (44.8 vs. 42.1%, p < 0.001) as opposed to women with stillbirth after 32 weeks. After adjustment, SGA birth weight (adjusted odds ratio [aOR] = 1.2, 95% confidence interval [CI]: 1.1-1.3), Black race (aOR = 1.2, 95% CI: 1.1-1.3), and CHTN (aOR = 1.3, 95% CI: 1.1-1.5) were associated with stillbirth prior to 32 weeks of gestation as opposed to stillbirth after 32 weeks. CONCLUSION: More than 6 out of 10 stillbirths in this study occurred <32 weeks of gestation, before ANFS is typically initiated under American College of Obstetricians and Gynecologists recommendations. Among identifiable risk factors, CHTN, Black race, and fetal growth restriction were associated with higher risk of stillbirth before 32 weeks of gestation. Earlier ANFS may be warranted at in certain "at risk" women. KEY POINTS: · Six out of 10 stillbirths occur before 32 weeks of gestation.. · We evaluated factors associated with stillbirth <32 weeks.. · Hypertension and fetal growth restriction were associated with early stillbirth..

Severe maternal morbidity associated with cerclage use in pregnancy.

OBJECTIVE: To quantify the frequency of serious maternal complications associated with cerclage use during pregnancy. STUDY DESIGN: We performed a retrospective population-based cohort study of all live births in Ohio from 2006 to 2015. Maternal sociodemographic, medical, and obstetric characteristics were compared for births in which cerclage was utilized during the pregnancy versus those without cerclage. The primary outcome for the study was a composite of adverse outcome including maternal intensive care unit (ICU) admission, blood product transfusion, uterine rupture and unplanned hysterectomy in all births. Secondary outcomes included each of the individual adverse outcomes as well as maternal hospital transfer to a tertiary facility, unplanned operation after delivery and chorioamnionitis. Each outcome was also analyzed separately in singleton and twin births. Generalized linear modeling was used to estimate the relative risk of adverse maternal outcomes associated with cerclage placement after adjustment for coexisting risk factors. RESULTS: Of the 1,428,655 singleton and twin live births in Ohio from 2006 to 2015, 4595 [0.3%] were recorded on the birth certificate as having cerclage during pregnancy. Of those, 11.7% experienced a serious adverse maternal outcome, compared to 3.7% without cerclage, adjRR 2.7 [95% CI 2.5, 3.0]. The rate of the composite maternal adverse outcome was significantly increased for pregnancies with cerclage versus those without overall, and in singleton and twin pregnancies when measured individually [all p ≤ .001]. Even after adjustment for coexisting risk factors, cerclage remained significantly associated with composite adverse outcome in each of these groups. CONCLUSIONS: Over 1 in 10 women with cerclage experience an adverse maternal outcome. Even after adjusting for gestational age at delivery and other risk factors, maternal risk for serious adverse event remains over twofold increased for pregnancies with cerclage. This information may be helpful in counseling women regarding potential maternal risk when considering neonatal benefit of cerclage in pregnancies at high risk of preterm birth.

Association between mode of delivery and infant survival at 22 and 23 weeks of gestation.

BACKGROUND: Cesarean delivery is currently not recommended before 23 weeks' gestation unless for maternal indications, even in the setting of malpresentation. These recommendations are based on a lack of evidence of improved neonatal outcomes and survival following cesarean delivery and the maternal risks associated with cesarean delivery at this early gestational age. However, as neonatal resuscitative measures and obstetrical interventions improve, studies evaluating the potential neonatal benefit of periviable cesarean delivery have reported inconsistent findings. OBJECTIVE: This study aimed to compare the survival rates at 1 year of life among resuscitated infants delivered by cesarean delivery with those delivered vaginally at 22 and 23 weeks of gestation. STUDY DESIGN: We conducted a population-based cohort study of all resuscitated livebirths delivered between 22 0/7 and 23 6/7 weeks of gestational age in the United States between 2007 and 2013. The primary outcome was the rate of infant survival at 1 year of life for different routes of delivery (cesarean vs vaginal delivery) at both 22 and 23 weeks of gestation. The secondary outcome variables included infant survival rates for neonates who survived beyond 24 hours of life, neonatal survival, and the length of survival. A secondary analysis also included a comparison of the infant survival rates between the different routes of delivery cohorts stratified by fetal presentation, steroid exposure, and ventilation. Information about composite adverse maternal outcomes were limited to infants who were delivered between 2011 and 2013 (when these items were first reported) and were defined as a requirement for blood transfusion, an unplanned operating room procedure following delivery, unplanned hysterectomy, and intensive care unit admission; the composite adverse maternal outcomes were also compared between the different delivery route cohorts for deliveries occurring between 22 and 23 weeks of gestation. Multivariable logistic regression analysis was used to determine the association between cesarean delivery and infant survival and other neonatal and maternal outcomes. RESULTS: Resuscitated infants delivered by cesarean delivery had higher rates of survival at 22 weeks (44.9 vs 23.0%; P<.001) and at 23 weeks (53.3 vs 43.4%; P<.001) of gestation regardless of fetal presentation. Multivariable logistic regression analysis demonstrated that infants who were delivered by cesarean delivery at 22 weeks (adjusted relative risk, 2.3; 95% confidence interval, 1.9-2.8) and 23 weeks (adjusted relative risk, 1.4; 95% confidence interval, 1.2-1.5) of gestation were more likely to survive than those delivered vaginally. When the cohort was limited to neonates who survived beyond the first 24 hours of life, vertex neonates born by cesarean delivery were not more likely to survive at 22 weeks (adjusted relative risk, 1.2; 95% confidence interval, 0.9-1.7) or 23 weeks (adjusted relative risk, 1.1; 95% confidence interval, 0.9-1.3) of gestation. An increased risk for composite adverse maternal outcomes (adjusted relative risk, 1.7; 95% confidence interval, 1.1-2.7) was associated with cesarean delivery at 22 to 23 weeks of gestation. CONCLUSION: Cesarean delivery is associated with increased survival at 1 year of life among resuscitated, periviable infants born between 22 0/7 and 23 6/7 weeks of gestation, especially in the setting of nonvertex presentation. However, cesarean delivery is associated with increased maternal morbidity.

Factors Associated With Maternal and Neonatal Interventions at the Threshold of Viability.

OBJECTIVE: To quantify the influence of maternal sociodemographic, medical, and pregnancy characteristics on decisions to offer or receive antepartum and neonatal interventions with deliveries occurring at 22-23 weeks of gestation. METHODS: This is a case-control study of U.S. live births at 22 0/7-23 6/7 weeks of gestation using National Center for Health Statistics vital statistics birth records from 2012 to 2016. We analyzed three outcomes in the treatment of periviable delivery: 1) maternal interventions (cesarean delivery, maternal hospital transfer or antenatal corticosteroid administration), 2) neonatal interventions (neonatal intensive care unit admission, surfactant administration, antibiotic administration, or assisted ventilation), and 3) combined interventions (at least one maternal and at least one neonatal intervention). Logistic regression estimated the influence of characteristics on interventions received. RESULTS: Of 19,844,580 U.S. live births from 2012 to 2016, 24,379 (0.12%) occurred at 22-23 weeks of gestation. Of these, 37.5% received maternal interventions, 51.7% received neonatal interventions, and 28.0% received combined interventions. Rates of births receiving at least one intervention were 38.9% and 78.3% for 22 and 23 weeks of gestation, respectively. Preeclampsia was the factor most positively associated with interventions. Other factors positively associated with interventions were increasing maternal age, Medicaid, low educational attainment, multiparity, twin gestation, and infertility treatment. Some factors had opposite influences on maternal compared with neonatal interventions. The presence of birth defects was positively associated with maternal interventions but negatively associated with neonatal interventions, whereas being of black race was negatively associated with maternal interventions but positively associated with neonatal interventions. CONCLUSION: Maternal and neonatal interventions occur frequently at the threshold of viability, especially at 23 weeks of gestation where the occurrence of interventions exceeds 50%. This study identifies sociodemographic and medical factors associated with using interventions with periviable deliveries. These data elucidate observed practice patterns in the management of periviable births and may assist providers in the counseling of women at risk of periviable birth.

Risk Calculator to Predict Cesarean Delivery Among Women Undergoing Induction of Labor.

OBJECTIVE: To develop and validate a predictive risk calculator for cesarean delivery among women undergoing induction of labor. METHODS: We performed a population-based cohort study of all women who had singleton live births after undergoing induction of labor from 32 0/7 to 42 6/7 weeks of gestation in the United States from 2012 to 2016. The primary objective was to build a predictive model estimating the probability of cesarean delivery after induction of labor using antenatal factors obtained from de-identified U.S. live-birth records. Multivariable logistic regression estimated the association of these factors on risk of cesarean delivery. K-fold cross validation was performed for internal validation of the model, followed by external validation using a separate live-birth cohort from 2017. A publicly available online calculator was developed after validation and calibration were performed for individual risk assessment. The seven variables selected for inclusion in the model by magnitude of influence were prior vaginal delivery, maternal weight at delivery, maternal height, maternal age, prior cesarean delivery, gestational age at induction, and maternal race. RESULTS: From 2012 to 2016, there were 19,844,580 live births in the United States, of which 4,177,644 women with singleton gestations underwent induction of labor. Among these women, 800,423 (19.2%) delivered by cesarean. The receiver operating characteristic curve for the seven-variable model achieved an area under the curve (AUC) of 0.787 (95% CI 0.786-0.788). External validation demonstrated a consistent measure of discrimination with an AUC of 0.783 (95% CI 0.764-0.802). CONCLUSION: This validated predictive model uses seven variables that were obtainable from the patient's medical record and discriminates between women at increased or decreased risk of cesarean delivery after induction of labor. This risk calculator, found at https://ob.tools/iol-calc, can be used in addition to the Bishop score by health care providers in counseling women who are undergoing an induction of labor and allocating appropriate resources for women at high risk for cesarean delivery.

Reported Prevalence of Maternal Hepatitis C Virus Infection in the United States.

OBJECTIVE: To quantify the reported prevalence and trend of maternal hepatitis C virus (HCV) infection in the United States (2009-2017) and identify maternal characteristics and obstetric outcomes associated with HCV infection during pregnancy. METHODS: We conducted a population-based retrospective cohort study of all live births in the United States for the period 2009 through 2017 using National Center for Health Statistics birth records. We estimated reported prevalence and trends over this time period for the United States. We also evaluated demographic factors and pregnancy outcomes associated with maternal HCV infection for a contemporary U.S. cohort (2014-2017). RESULTS: During the 9-year study period, there were 94,824 reported cases of maternal HCV infection among 31,207,898 (0.30%) live births in the United States. The rate of maternal HCV infection increased from 1.8 cases per 1,000 live births to 4.7 cases per 1,000 live births (relative risk [RR] 2.7, 95% CI 2.6-2.8) in the United States. After adjusting for various confounders in the contemporary U.S. cohort (2014-2017), demographic characteristics associated with HCV infection included non-Hispanic white race (adjusted RR 2.8, 95% CI 2.7-2.8), Medicaid insurance (adjusted RR 3.3, CI 3.2-3.3), and cigarette smoking (adjusted RR 11.1, CI 10.9-11.3). Co-infection during pregnancy with hepatitis B (adjusted RR 19.2, CI 18.1-20.3), gonorrhea, chlamydia, or syphilis were also associated with maternal HCV infection. Obstetric and neonatal outcomes associated with maternal HCV infection included cesarean delivery, preterm birth, maternal intensive care unit admission, blood transfusion, having small-for-gestational-age neonates (less than the 10th percentile) birth weight, neonatal intensive care unit admission, need for assisted neonatal ventilation, and neonatal death. CONCLUSION: The reported prevalence of maternal HCV infection has increased 161% from 2009 to 2017.

Effect of Needle Exchange Program on Maternal Hepatitis C Virus Prevalence.

OBJECTIVE: This study aimed to quantify the prevalence of maternal hepatitis C virus (HCV) before and after implementation of the needle exchange program (NEP) in Scioto County, Ohio. STUDY DESIGN: We conducted a population-based retrospective cohort study of all live births in Ohio (2006-2015). Frequency of maternal HCV was compared before (2006-2011) and after (2012-2015) the implementation of an NEP (2011) in Portsmouth, Ohio (Scioto County). Trends in maternal HCV prevalence in neighboring counties both physically adjacent and regional to Scioto County were also evaluated before and after NEP implementation. RESULTS: During the study period, there were 7,069 reported cases of maternal HCV infection at the time of delivery among 1,463,506 (0.5%) live births in Ohio. The rate of maternal HCV infection increased 137% in Scioto County between 2006 and 2011. After initiation of the NEP in Portsmouth, Ohio, in 2011, the rate of increase in the following 4 years (2012-2015) was 12%. The rate of increase in maternal HCV declined precipitously in counties physically adjacent to Scioto County, whereas regional counties continued to have substantial increases in maternal HCV. CONCLUSION: Rate of maternal HCV infection increased 137% versus 12% (rate difference: 125%) between pre- and post-NEP implementation time periods in Scioto County.

Variants in the fetal genome near pro-inflammatory cytokine genes on 2q13 associate with gestational duration.

The duration of pregnancy is influenced by fetal and maternal genetic and non-genetic factors. Here we report a fetal genome-wide association meta-analysis of gestational duration, and early preterm, preterm, and postterm birth in 84,689 infants. One locus on chromosome 2q13 is associated with gestational duration; the association is replicated in 9,291 additional infants (combined P = 3.96 × 10-14). Analysis of 15,588 mother-child pairs shows that the association is driven by fetal rather than maternal genotype. Functional experiments show that the lead SNP, rs7594852, alters the binding of the HIC1 transcriptional repressor. Genes at the locus include several interleukin 1 family members with roles in pro-inflammatory pathways that are central to the process of parturition. Further understanding of the underlying mechanisms will be of great public health importance, since giving birth either before or after the window of term gestation is associated with increased morbidity and mortality.

Predictive Model for Failed Induction of Labor Among Obese Women.

OBJECTIVE: To evaluate antenatal risk factors associated with failed induction of labor among obese women to develop a predictive model for induction of labor outcome. METHODS: We conducted a population-based cohort study of all obese (body mass index higher than 30.0) women with singleton live births who underwent attempted induction of labor between 37 and 44 weeks of gestation in the United States from 2012 to 2016 using de-identified U.S live birth records. The primary objective was to build a predictive model for the probability of induction of labor failure using antenatal factors. Multivariable logistic regression estimated the association of these factors on risk of failed induction of labor. We performed k-fold cross-validation for internal validation and then externally validated the model using a separate live birth cohort from 2017 (n=197,982). An online calculator was developed after validation, and calibration was performed. The 10 variables selected for inclusion in the model in order of significance were prior vaginal delivery, prior cesarean delivery, maternal height, age, weight at delivery, parity, gestational weight gain, Medicaid insurance, pregestational diabetes, and chronic hypertension. RESULTS: Among 19,844,580 live births in the United States between 2012 and 2016, 1,098,981 obese women with singleton pregnancies underwent induction of labor, of which 273,184 (24.9%) were unsuccessful. The receiver operator characteristic curve for the 10 variable model achieved an area under the curve (AUC) of 0.79 (95% CI 0.78-0.79). External validation demonstrated a consistent measure of discrimination, with an AUC curve of 0.77 (95% CI 0.76-0.77). CONCLUSION: This model provides valuable estimation as to the cumulative effect of multiple factors on the risk of failed induction of labor among obese parturients. The predictive model identifies women at increased or decreased risk (ie, greater than 75% vs less than 20%) for cesarean delivery. This risk calculator may be a useful tool for practitioners in the counseling, triaging, risk stratifying, and delivery planning for obese women before attempted induction of labor.

Predictive Model of Factors Associated With Maternal Intensive Care Unit Admission.

OBJECTIVE: Severe maternal morbidity has increased in the United States over the past two decades by approximately 200%, to 144 cases per 10,000 delivery hospitalizations. There are limited data available to assist in identifying at-risk women before parturition. We sought to evaluate risk factors associated with maternal admission to an intensive care unit (ICU). METHODS: We conducted a population-based cohort study of all live births delivered between 20 and 44 weeks of gestation in the United States during 2012-2016. Our primary objective was to identify prenatal factors associated with increased risk of maternal ICU admission to build a multivariable predictive model to estimate the association of these factors with ICU admission risk. We performed k-fold cross-validation for internal validation and then externally validated the model on a separate live birth cohort (2006-2011, n=856,255). RESULTS: There were 18,745,615 live births in the United States between 2012 and 2016. Among the mothers of these live newborns, 27,602 (0.15%) were admitted to the ICU in the peripartum period. Fourteen variables were selected for inclusion in the predictive model for maternal ICU admission. The predicted minimal and maximal risk for ICU admission ranged 0-25%. The receiver operating characteristic curve for these 14 variables achieved an area under the curve (AUC) of 0.81 (95% CI 0.79-0.81). External validation with a separate live birth cohort demonstrated a consistent measure of discrimination with an AUC of 0.83 (95% CI 0.82-0.84). Using a relatively high cut point of 5.0% or more predicted risk for ICU admission, achieved a positive predictive value (PPV) of only 4.0%. CONCLUSION: This model provides insight as to the cumulative effect of multiple risk factors on maternal ICU admission risk. The predictive model achieves an AUC of 0.81, discriminating women with significantly increased risk (30-fold) for ICU admission. Nonetheless, because of the low frequency of maternal ICU admission, the PPV of the model was low and therefore whether models such as ours may be beneficial in future efforts to reduce the prevalence and burden of maternal morbidity is uncertain.

Contemporary Trends in Cesarean Delivery Utilization for Live Births Between 22 0/7 and 23 6/7 Weeks of Gestation.

OBJECTIVE: In 2014, the Society for Maternal-Fetal Medicine, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, the American Academy of Pediatrics, and the American College of Obstetricians and Gynecologists published an executive summary of a joint workshop to establish obstetric interventions to be considered for periviable births. We sought to evaluate changes in practice patterns since the publication of these guidelines. METHODS: We conducted a population-based cohort study of all singleton live births delivered between 22 0/7 and 23 6/7 weeks of gestation in the United States within two time epochs: pre-executive summary (Epoch 1: 2012-2013) and post-executive summary (Epoch 2: 2015-2016) guideline release. The primary outcome was the difference in the rate of cesarean delivery between pre-executive summary and post-executive summary guideline publication. Secondary outcomes included differences in rates of individual and composite neonatal interventions (neonatal intensive care unit admission, ventilation, surfactant and antibiotic administration), maternal adverse outcomes (intensive care unit admission, transfusion, hysterectomy, uterine rupture), and neonatal mortality. Multivariable logistic regression estimated the association of delivery epoch with outcomes. RESULTS: There were 15,846,405 live births in the United States between 2012-2013 and 2015-2016, of which 14,799 (0.1%) were singletons delivered between 22 and 24 weeks of gestation. Among these live births, 7,374 (52.3%) were delivered in Epoch 1 and 7,425 (47.7%) in Epoch 2. Cesarean delivery rates increased from Epoch 1 to Epoch 2 (24.3% vs 28.4%, P<.001), which was attributable to increased cesarean utilization during the 23rd week (36.3% vs 40.8%, difference 4.5%, 95% CI 2.3-6.6). Likewise, the rate of composite neonatal interventions increased (50.6% vs 56.9%, difference 6.3%, 95% CI 4.6-8.0) between Epochs 1 and 2, in association with a slight reduction in neonatal mortality (67.2% vs 64.6%, P=.009). There was no statistically significant difference in composite (8.9% vs 9.5%, P=.261) adverse maternal outcomes between delivery epochs. CONCLUSION: The frequency of delivery by cesarean in the 23rd week increased by 4.5% after publication of the periviable birth executive summary. The observed increase in cesarean delivery and composite neonatal interventions between delivery cohorts was associated with a small reduction in neonatal mortality.

Mode of Delivery in Previable Births.

OBJECTIVE: Preterm birth before 23 weeks of gestation typically results in neonatal death (5% survival). Society for Maternal-Fetal Medicine and American College of Obstetricians and Gynecologists published consensus guidelines recommending cesarean delivery (CD) not be performed for fetal indications between 20 and 226/7 weeks given the lack of proven benefit. We sought to quantify the previable CD rate and identify characteristics associated with previable CD. METHODS: We performed a population-based retrospective cohort study of all live births in Ohio (2006-2015). Frequency of previable CD was stratified by week of gestation, defined as delivery between 16 and < 23 weeks of gestation. Maternal, obstetric, and neonatal characteristics were compared between women who underwent vaginal delivery versus CD. Multivariable logistic regression estimated the relative influence of maternal and fetal factors on the outcome of CD among previable live births. RESULTS: Of 1,463,506 live births in Ohio during the 10-year study period, 2,865 births (0.2%) occurred during the previable period of 16 to 22 weeks. Nearly 1 in 10 live births at less than 23 weeks was delivered by cesarean (n = 273/2,865), CD rate 9.5% (95% confidence interval, 8.5-10.7). At 16 to 22 weeks of gestation, the CD rates were 0, 5.5, 7.6, 3.5, 5.4, 10.1, and 15.1%, respectively. Factors associated with CD included increasing parity, increasing birth weight, maternal corticosteroid administration, and fetal malpresentation. Previable neonates born by CD were more likely to be admitted to the NICU, receive ventilator support, and more likely to be living at the time of birth certificate filing. CONCLUSION: Nearly 1 out of 10 births during the previable period was delivered via cesarean. Factors associated with previable CD suggest intent for neonatal interventions, such as NICU admission and supportive therapies. Our findings support that education and adherence with guidelines for care of previable births are a potential area of focus for perinatal quality improvement efforts.

Comparison of prostaglandin and mechanical cervical ripening in the setting of small for gestational age neonates.

Objective: The objective of this study is to determine whether cervical ripening with misoprostol (MP) is associated with higher rates of cesarean delivery (CD) compared with dinoprostone (DP) or Pitocin/Foley balloon (PFB) in infants found to be small for gestational age (SGA). Study design: Single center institution based cohort study of all inductions between 2008 and 2012 where birth weight was found to be as SGA (< 10th percentile). Maternal demographic, obstetric, and labor characteristics were compared between SGA births where cervical ripening with MP, DP, or PFB was used as the primary agent. The primary outcome was CD after attempted induction between the three study groups which included MP, DP, and PFB. Secondary outcomes included inability to achieve active labor (defined as cervical dilation of 6 cm or greater), cervical dilation at the time of CD, the incidence of CD for the indication of non-reassuring fetal status, and neonatal outcomes including Apgar scores and admission to neonatal intensive care unit. Multivariable logistic regression was performed to evaluate the association of these outcomes with MP as the induction agent versus the referent groups, PFB. Results: Of 260 inductions where the infant was found to be SGA by birth weight during the 5-year period, 172 (66.2%) patients were induced using MP, 38 (14.6%) with DP, and 50 (19.2%) with PFB. There were no differences in baseline characteristics between groups (age, race, BMI, parity, induction indication, birth weights, or maternal comorbidities). MP did not increase rate of CD which was 25.6%, 26.3%, and 22.0% in the MP, DP, and PFB groups, respectively (p = .86). There were also no differences in incidence of CD for non-reassuring fetal well-being (NRFWB), failure to attain active labor, or cervical dilation at time of CD between induction groups. NICU admission was 18%, 18%, and 16% (p = .94) between MP, DP, and PFB groups, respectively. MP was not associated with an increased rate of CD when compared with the other two agents combined, aOR 0.93 (0.67-1.30, 95% CI). Conclusion: MP appears to have similar efficacy and safety when compared with other cervical ripening agents in pregnancies complicated by SGA.

Severe adverse maternal outcomes associated with chorioamnionitis.

BACKGROUND: Chorioamnionitis complicates 1-5% of all pregnancies and is associated with substantial neonatal morbidity. Prolonged labor and increased use of labor induction may lead to increased rates of chorioamnionitis. OBJECTIVE: We sought to quantify serious adverse maternal outcomes that are associated with chorioamnionitis in a contemporary population of live births in the state of Ohio. STUDY DESIGN: We conducted a population-based retrospective cohort study of all live births in Ohio (2006-2015). Maternal demographic and obstetric outcomes, as reported on the US birth certificate, were compared between women with and without chorioamnionitis. Primary study outcomes were maternal intensive care unit admission and composite adverse maternal outcome (intensive care unit admission, blood product transfusion, unplanned hysterectomy, unplanned operation after delivery, or ruptured uterus). Multivariate logistic regression estimated the relative association of chorioamnionitis with maternal adverse outcomes. RESULTS: Of 1,393,054 live births in Ohio over 10 years, 17,430 live births (1.3%) had chorioamnionitis. Women with chorioamnionitis had significantly higher rates of maternal intensive care unit admission (0.5% vs 0.1%; P<.001) and composite adverse outcome (5.0% vs 1.5%; P<.001) compared with those without chorioamnionitis. Even after adjustment for coexisting risks, chorioamnionitis was associated with 2- to 3-fold increased risk of composite adverse outcome, maternal intensive care unit admission, blood transfusion, ruptured uterus, and unplanned operation after delivery. Sensitivity analysis that excluded women who delivered by cesarean section revealed persistent significant associations between chorioamnionitis and adverse maternal outcomes. The rate of composite adverse outcomes was higher at earlier gestational ages. However, the relative risk increase of adverse outcome was more pronounced with advancing gestational age at delivery. CONCLUSION: The frequency of severe adverse outcomes in pregnancies that are complicated with chorioamnionitis is high, with 1 in every 20 cases affected, and includes an almost 3-fold increased risk for maternal intensive care unit admission compared with patients without chorioamnionitis. Efforts to prevent and treat chorioamnionitis to minimize maternal risk could be an important area of focus in the reduction of the rate of severe maternal morbidity in the United States.

Mode of delivery in antepartum stillbirths.

OBJECTIVE: Stillbirth complicates 1 in 160 pregnancies in the United States. We sought to determine the rate of cesarean delivery in pregnancies complicated by antepartum stillbirth and to identify characteristics associated with cesarean delivery. STUDY DESIGN: This was a population-based retrospective cohort study of all stillbirths in the United States during the year of 2014. Frequency of cesarean delivery was stratified by week of gestation. Maternal, obstetric, and fetal characteristics were compared between women with antepartum stillbirth who underwent cesarean delivery compared with vaginal delivery. Multivariate logistic regression estimated the relative influence of maternal, obstetric, and fetal factors on the outcome of cesarean delivery. RESULTS: There were 16,160 nonlaboring women diagnosed with stillbirth during 2014 in the United States. Of the 16,160 stillbirths, 2449 (15.2%) underwent cesarean delivery. At 20-23, 24-27, 28-31, 32-36, and >36 weeks of gestation, the cesarean delivery rate was 4.0%, 16.2%, 23.7%, 30.8%, and 28.8%, respectively. Factors associated with cesarean delivery included gestational diabetes, preeclampsia, use of assisted reproductive technology, history of prior cesarean delivery, and increasing gestational age at delivery. CONCLUSION: Approximately 15% of women diagnosed with a stillbirth after 16 weeks of gestation underwent a cesarean delivery in 2014. The stillbirth cesarean delivery rate peaked during the third trimester, during which more than 1 in 4 women underwent a cesarean birth.