Virtual Obstetric Hospitalist Support for Obstetric Emergencies and Deliveries: The Mayo Clinic Experience.

Objective: To implement use of obstetric (OB) hospitalist telemedicine services (TeleOB) to support clinicians facing OB emergencies in low-resource hospital settings. Methods: TeleOB was staffed by OB hospitalists working at a tertiary maternity center. The service was available via real-time high-definition audio/video technology for providers at 17 outlying hospitals across a health system spanning two states. The initial 25 service activations are described. Results: TeleOB supported 17 deliveries, two postpartum emergency department (ED) consultations, and four antenatal ED consultations. In 10 of 17 (59%) deliveries, teleneonatology was jointly activated to support neonatal resuscitation. Sixteen (94%) deliveries occurred in multiparas, and five (29%) resulted from spontaneous preterm labor. Eighty percent (20/25) of activations occurred in facilities without maternity services. Conclusions: A TeleOB service staffed by OB hospitalists successfully supports hospitals in an integrated health care system. TeleOB is feasible for support of hospitals with no delivery facilities or with limited maternity care resources.

Screening for and Experiences of Intimate Partner Violence in the United States Before, During, and After Pregnancy, 2016-2019.

Objectives. To measure rates of intimate partner violence (IPV) screening during the perinatal period among people experiencing physical violence in the United States. Methods. We used 2016-2019 Pregnancy Risk Assessment Monitoring System data (n = 158 338) to describe the incidence of physical IPV before or during pregnancy. We then assessed the prevalence of IPV screening before, during, or after pregnancy and predictors of receiving screening among those reporting violence. Results. Among the 3.5% (n = 6259) of respondents experiencing violence, 58.7%, 26.9%, and 48.3% were not screened before, during, or after pregnancy, respectively. Those reporting Medicaid or no insurance at birth, American Indian/Alaska Native people, and Spanish-speaking Hispanic people faced increased risk of not having a health care visit during which screening might occur. Among those attending a health care visit, privately insured people, rural residents, and non-Hispanic White respondents faced increased risk of not being screened. Conclusions. Among birthing people reporting physical IPV, nearly half were not screened for IPV before or after pregnancy. Public health efforts to improve maternal health must address both access to care and universal screening for IPV. (Am J Public Health. 2023;113(3):297-305. https://doi.org/10.2105/10.2105/AJPH.2022.307195).

Comparison of Maternal and Neonatal Subspecialty Care Provision by Hospital.

OBJECTIVE: The aim of the study is to determine the relationship between a hospital's provision of subspecialty neonatal and maternal care. Specifically, we sought to understand where women with high-risk maternal conditions received intrapartum care and estimate the potential transfer burden for those with maternal high-risk conditions delivering at hospitals without subspecialty maternal care. STUDY DESIGN: This is a descriptive study using data from 2015 State Inpatient Databases and the American Hospital Association Annual Survey. Characteristics were compared between hospitals based on the concordance of their maternal and neonatal care. The incidences of high-risk maternal conditions (pre-eclampsia with severe features, placenta previa with prior cesarean delivery, cardiac disease, pulmonary edema, and acute liver failure) were compared. To determine the potential referral burden, the percent of women with high-risk conditions delivering at a hospital without subspecialty maternal care but delivering in a county with a hospital with subspecialty maternal care was calculated. RESULTS: The analysis included 486,398 women who delivered at 544 hospitals, of which 104 (19%) and 182 (33%) had subspecialty maternal and neonatal care, respectively. Ninety-eight hospitals provided both subspecialty maternal and neonatal care; however, 84 hospitals provided only subspecialty neonatal care but no subspecialty maternal care. Among high-risk maternal conditions examined, approximately 65% of women delivered at a hospital with subspecialty maternal care. Of the remainder who delivered at a hospital without subspecialty maternal care, one-third were in a county where subspecialty care was present. For women with high-risk conditions who delivered in a county without subspecialty maternal care, the median distance to the closest county with subspecialty care was 52.8 miles (IQR: 34.3-87.7 miles). CONCLUSION: Approximately 50% of hospitals with subspecialty neonatal care do not provide subspecialty maternal care. This discordance may present a challenge when both high-risk maternal and neonatal conditions are present. KEY POINTS: · High-risk women who deliver at hospitals without subspecialty care are in more rural areas.. · Approximately 50% of hospitals with subspecialty neonatal care do not provide subspecialty maternal care.. · This discordance may present a challenge when both high-risk maternal and neonatal conditions are present..

Maternal and neonatal outcomes among incarcerated women who gave birth in custody.

BACKGROUND: In the United States, the population of incarcerated women has increased by more than 600% since the 1980s. With this rise, correctional facilities have faced new challenges meeting the health care needs of women, especially those who are pregnant. This retrospective cohort study sought to describe five indicators of maternal and neonatal health among women who gave birth in custody, and to compare outcomes among incarcerated women who did and did not receive enhanced pregnancy support. METHODS: We used deidentified electronic health records (EHRs) to examine maternal and neonatal birth outcomes (ie, mode of birth, low birthweight, preterm birth, APGAR score, NICU admission) among women who gave birth in custody. Regression models examined differences in outcomes between women who received enhanced pregnancy support-group prenatal education and one-on-one doula visits-and a historical control group of women who received standard prenatal care. RESULTS: Adverse maternal and neonatal birth outcomes in this sample were rare. No differences in outcomes were found between incarcerated women who received enhanced pregnancy support and the historical control group. CONCLUSIONS: Despite evidence for the benefits of enhanced pregnancy support in the general population, this study did not find differences in outcomes between incarcerated women who did and did not receive support. Integrated data from prison and hospital records are innovative, but effect measurement is limited by sample size. Future research should include primary data collection on maternal, neonatal, and dyadic outcomes longitudinally and across prisons.

Perinatal insurance coverage and behavioural health-related maternal mortality.

Increases in postpartum maternal deaths, including a substantial number associated with behavioural health conditions, are a public health crisis and have contributed to overall increases in maternal mortality. A leading hypothesis to explain this pattern suggests lack of availability or continuity of resources for behavioural health treatment after delivery, often secondary to lapses in insurance coverage. Extending postpartum Medicaid coverage through the first year postpartum could mitigate excess morbidity and mortality among postpartum individuals, particularly those with behavioural health conditions.

Racial and Ethnic Differences in Self-Rated Health Among Rural Residents.

This study examines racial and ethnic differences in self-rated health among rural residents and whether these differences can be explained by socio-demographic characteristics. We used data from the 2011-2017 National Health Interview Survey to assess differences in self-rated health by race and ethnicity among rural residents (living in non-metropolitan counties; n = 46,883). We used logistic regression analyses to estimate the odds of reporting fair/poor health after adjusting for individual socio-demographic characteristics. Non-Hispanic Black and American Indian rural residents reported worse self-rated health than their non-Hispanic White counterparts (25.8% and 20.8% reporting fair/poor health, respectively, vs. 14.8%; p < 0.001). After adjusting for socio-demographic characteristics, disparities remained for non-Hispanic Black rural residents (Adjusted Odds Ratio = 1.55; 95% CI 1.36, 1.76). This study suggests more attention is required to address inequities among rural people and to develop policies to address structural racism and improve the health of all rural residents.

Racial and Ethnic Diversity in the Nursing Workforce: A Focus on Maternity Care.

Racial and ethnic inequities in health are a national crisis requiring engagement across a range of factors, including the health care workforce. Racial inequities in maternal and infant health are an increasing focus of attention in the wake of rising rates of maternal morbidity and mortality in the United States. Efforts to achieve racial equity in childbirth should include attention to the nurses who provide care before and during pregnancy, at childbirth, and postpartum.

Practice Patterns of Physicians and Nurse Practitioners in Primary Care.

BACKGROUND: Primary care practices increasingly include nurse practitioners (NPs), in addition to physicians. Little is known about how the patient mix and clinical activities of colocated physicians and NPs compare. OBJECTIVES: To describe the clinical activities of NPs, compared with physicians. RESEARCH DESIGN: We used claims and electronic health record data from athenahealth Inc., on primary care practices in 2017 and a cross-sectional analysis with practice fixed effects. SUBJECTS: Patients receiving treatment from physicians and NPs within primary care practices. MEASURES: First, we measured patient characteristics (payer, age, sex, race, chronic condition count) and visit characteristics (new patient, scheduled duration, same-day visit, after-hours visit). Second, we measured procedures performed and diagnoses recorded during each visit. Finally, we measured daily quantity (visit volume, minutes scheduled for patient care, total work relative value units billed) of care. RESULTS: Relative to physicians, NPs treated younger and healthier patients. NPs also had a larger share of patients who were female, non-White, and covered by Medicaid, commercial insurance, or no insurance. NPs scheduled longer appointments and treated more patients on a same-day or after-hours basis. On average, "overlapping" services-those performed by NPs and physicians within the same practice-represented 92% of all service volume. The small share of services performed exclusively by physicians reflected greater clinical intensity. On a daily basis, NPs provided fewer and less intense visits than physicians within the same practice. CONCLUSIONS: Our findings suggest considerable overlap between the clinical activities of colocated NPs and physicians, with some differentiation based on intensity of services provided.

Characteristics of US Rural Hospitals by Obstetric Service Availability, 2017.

Objectives. To describe characteristics of rural hospitals in the United States by whether they provide labor and delivery (obstetric) care for pregnant patients.Methods. We used the 2017 American Hospital Association Annual Survey to identify rural hospitals and describe their characteristics based on the lack or provision of obstetric services.Results. Among the 2019 rural hospitals in the United States, 51% (n = 1032) of rural hospitals did not provide obstetric care. These hospitals were more often located in rural noncore counties (counties with no town of more than 10 000 residents). Rural hospitals without obstetrics also had lower average daily censuses, were more likely to be government owned or for profit compared with nonprofit ownership, and were more likely to not have an emergency department compared with hospitals providing obstetric care (P for all comparisons < .001).Conclusions. Rural US hospitals that do not provide obstetric care are located in more sparsely populated rural locations and are smaller than hospitals providing obstetric care.Public Health Implications. Understanding the characteristics of rural hospitals by lack or provision of obstetric services is important to clinical and policy efforts to ensure safe maternity care for rural residents.

Midwife-led care and obstetrician-led care for low-risk pregnancies: A cost comparison.

OBJECTIVE: Low-risk pregnant women cared for by midwives have similar birth outcomes to women cared for by physicians, although experiencing fewer medical procedures. However, limited research has assessed cost implications in the United States. Using national data, we assessed costs and resource use of midwife-led care vs obstetrician-led care for low-risk pregnancies using a decision-analytic approach. METHODS: We developed a decision-analytic model of costs (health plan payments to clinicians) and use of medical procedures during childbirth (epidural analgesia, labor induction, cesarean birth, episiotomy) and outcomes of care (birth at preterm gestation) that may differ with midwife-led vs obstetrician-led care. Model parameters for obstetric procedures were generated using Listening to Mothers III data, a national survey of women who gave birth in US hospitals in 2011-2012 and other published estimates. Cost estimates came from published or publicly available information on health insurance claims payments. RESULTS: The costs of childbirth for low-risk women with midwife-led care were, on average, $2262 less than births to low-risk women cared for by obstetricians. These cost differences derive from lower rates of preterm birth and episiotomy among women with midwife-led care, compared with obstetrician-led care. Across the population of US women with low-risk births each year (approximately 2.6 million), the model predicted substantially fewer preterm births (167 259 vs 219 427 for midwife-led vs obstetrician-led care) and fewer episiotomies (170 504 vs 415 686, for midwife-led vs obstetrician-led care). CONCLUSIONS: A shift from obstetrician-led care to midwife-led care for low-risk pregnancies could be cost saving.

Amphetamine- and Opioid-Affected Births: Incidence, Outcomes, and Costs, United States, 2004-2015.

Objectives. To estimate trends in incidence, outcomes, and costs among hospital deliveries related to amphetamines and opioids.Methods. We analyzed 2004-to-2015 data from the National Inpatient Sample, a nationally representative sample of hospital discharges in the United States compiled by the Healthcare Cost and Utilization Project, by using a repeated cross-sectional design. We estimated the incidence of hospital deliveries related to maternal amphetamine or opioid use with weighted logistic regression. We measured clinical outcomes and costs with weighted multivariable logistic regression and generalized linear models.Results. Amphetamine- and opioid-related deliveries increased disproportionately across rural compared with urban counties in 3 of 4 census regions between 2008 to 2009 and 2014 to 2015. By 2014 to 2015, amphetamine use was identified among approximately 1% of deliveries in the rural West, which was higher than the opioid-use incidence in most regions. Compared with opioid-related and other hospital deliveries, amphetamine-related deliveries were associated with higher incidence of preeclampsia, preterm delivery, and severe maternal morbidity and mortality.Conclusions. Increasing incidence of amphetamine and opioid use among delivering women and associated adverse gestational outcomes indicate that amphetamine and opioid use affecting birth represent worsening public health crises.

Women's preference for vaginal birth after a first delivery by cesarean.

BACKGROUND: Nearly 90% of United States pregnant women with a prior cesarean give birth by repeat cesarean. Public health goals encourage greater use of vaginal birth after cesarean (VBAC), but there is little prospective data on predictors of women's preference for VBAC. We characterized predictors of women's preferred mode of delivery after a first cesarean and thematically categorized reasons for their preference. METHODS: Data were from a cohort of 3006 women whose first childbirth was in Pennsylvania in 2009-2011. The analytic sample included women who had their first birth by cesarean and reported mode of delivery preference for their next delivery at 12 months postpartum (n = 616). Associations with future birth mode preference were assessed using multivariate logistic regression, and reasons for preference were categorized using content analysis. RESULTS: At 12 months postpartum, 45% of women who delivered by cesarean in their first birth wanted to have their next delivery vaginally. Independent predictors of VBAC preference were Black race/ethnicity, nonrecurrent indication for the first cesarean, planning three or more additional children, and difficulty recovering from the first cesarean. The most common reason for preferring a vaginal birth was wanting the experience of vaginal birth; the most common reason for preferring cesarean birth was that the first birth was by cesarean. CONCLUSION: Nearly half of respondents preferred VBAC in future births, but national estimates indicate that only about 12% of women with prior cesareans have a VBAC. This suggests a need to ensure greater access to VBAC for women who want it.

Area-level deprivation and preterm birth: results from a national, commercially-insured population.

BACKGROUND: Area-level deprivation is associated with multiple adverse birth outcomes. Few studies have examined the mediating pathways through which area-level deprivation affects these outcomes. The objective of this study was to investigate the association between area-level deprivation and preterm birth, and examine the mediating effects of maternal medical, behavioural, and psychosocial factors. METHODS: We conducted a retrospective cohort study using national, commercial health insurance claims data from 2011, obtained from the Health Care Cost Institute. Area-level deprivation was derived from principal components methods using ZIP code-level data. Multilevel structural equation modeling was used to examine mediating effects. RESULTS: In total, 138,487 women with a live singleton birth residing in 14,577 ZIP codes throughout the United States were included. Overall, 5.7% of women had a preterm birth. In fully adjusted generalized estimation equation models, compared to women in the lowest quartile of area-level deprivation, odds of preterm birth increased by 9.6% among women in the second highest quartile (odds ratio (OR) 1.096; 95% confidence interval (CI) 1.021, 1.176), by 11.3% in the third highest quartile (OR 1.113; 95% CI 1.035, 1.195), and by 24.9% in the highest quartile (OR 1.249; 95% CI 1.165, 1.339). Hypertension and infection moderately mediated this association. CONCLUSIONS: Even among commercially-insured women, area-level deprivation was associated with increased risk of preterm birth. Similar to individual socioeconomic status, area-level deprivation does not have a threshold effect. Implementation of policies to reduce area-level deprivation, and the screening and treatment of maternal mediators may be associated with a lower risk of preterm birth.

Cesarean Delivery Rates and Costs of Childbirth in a State Medicaid Program After Implementation of a Blended Payment Policy.

BACKGROUND: Nearly half of US births are financed by Medicaid, and one-third of births occur by cesarean delivery, at double the cost of vaginal delivery. With the goal of reducing unnecessary cesarean use and improving value, in 2009 Minnesota's Medicaid program introduced a blended payment rate for uncomplicated births (ie, a single facility or professional services payment regardless of delivery mode). OBJECTIVE: We evaluated the effect of the blended payment policy on cesarean use and costs for Medicaid fee-for-service births. METHODS: We identified births in Medicaid Analytic Extract files from 3 years before and after the 2009 payment change in Minnesota and in 6 control states. We used a quarterly interrupted time series approach to assess policy-related changes in study outcomes, comparing Minnesota to control states. Outcomes included cesarean delivery, childbirth hospitalization costs, and maternal morbidity. RESULTS: Minnesota's prepolicy cesarean rate (22.8%) decreased 0.27 percentage points per quarter after the policy for a total decrease of 3.24 percentage points, compared with control states (P=0.01). The cost of childbirth hospitalizations in Minnesota dropped by $425.80 at the time of the policy. Postpolicy, childbirth hospitalization costs continued to decrease in Minnesota relative to prepolicy by $95.04 per quarter, and declined more than control states (P<0.001). There were no significant policy effects on maternal morbidity. CONCLUSIONS: Implementation of a single, blended payment to facilities and clinicians for uncomplicated births mitigated trends toward greater use of cesarean and rising costs of childbirth hospitalization, without adverse effects on maternal morbidity.

Paid Maternity Leave in the United States: Associations with Maternal and Infant Health.

Objectives The United States is one of only three countries worldwide with no national policy guaranteeing paid leave to employed women who give birth. While maternity leave has been linked to improved maternal and child outcomes in international contexts, up-to-date research evidence in the U.S. context is needed to inform current policy debates on paid family leave. Methods Using data from Listening to Mothers III, a national survey of women ages 18-45 who gave birth in 2011-2012, we conducted multivariate logistic regression to predict the likelihood of outcomes related to infant health, maternal physical and mental health, and maternal health behaviors by the use and duration of paid maternity leave. Results Use of paid and unpaid leave varied significantly by race/ethnicity and household income. Women who took paid maternity leave experienced a 47% decrease in the odds of re-hospitalizing their infants (95% CI 0.3, 1.0) and a 51% decrease in the odds of being re-hospitalized themselves (95% CI 0.3, 0.9) at 21 months postpartum, compared to women taking unpaid or no leave. They also had 1.8 times the odds of doing well with exercise (95% CI 1.1, 3.0) and stress management (95% CI 1.1, 2.8), compared to women taking only unpaid leave. Conclusions for Practice Paid maternity leave significantly predicts lower odds of maternal and infant re-hospitalization and higher odds of doing well with exercise and stress management. Policies aimed at expanding access to paid maternity and family leave may contribute toward reducing socio-demographic disparities in paid leave use and its associated health benefits.

Association Between Loss of Hospital-Based Obstetric Services and Birth Outcomes in Rural Counties in the United States.

Importance: Hospital-based obstetric services have decreased in rural US counties, but whether this has been associated with changes in birth location and outcomes is unknown. Objective: To examine the relationship between loss of hospital-based obstetric services and location of childbirth and birth outcomes in rural counties. Design, Setting, and Participants: A retrospective cohort study, using county-level regression models in an annual interrupted time series approach. Births occurring from 2004 to 2014 in rural US counties were identified using birth certificates linked to American Hospital Association Annual Surveys. Participants included 4 941 387 births in all 1086 rural counties with hospital-based obstetric services in 2004. Exposures: Loss of hospital-based obstetric services in the county of maternal residence, stratified by adjacency to urban areas. Main Outcomes and Measures: Primary outcomes were county rates of (1) out-of-hospital births; (2) births in hospitals without obstetric units; and (3) preterm births (<37 weeks' gestation). Results: Between 2004 and 2014, 179 rural counties lost hospital-based obstetric services. Of the 4 941 387 births studied, the mean (SD) maternal age was 26.2 (5.8) years. A mean (SD) of 75.9% (23.2%) of women who gave birth were non-Hispanic white, and 49.7% (15.6%) were college graduates. Rural counties not adjacent to urban areas that lost hospital-based obstetric services had significant increases in out-of-hospital births (0.70 percentage points [95% CI, 0.30 to 1.10]); births in a hospital without an obstetric unit (3.06 percentage points [95% CI, 2.66 to 3.46]); and preterm births (0.67 percentage points [95% CI, 0.02 to 1.33]), in the year after loss of services, compared with those with continual obstetric services. Rural counties adjacent to urban areas that lost hospital-based obstetric services also had significant increases in births in a hospital without obstetric services (1.80 percentage points [95% CI, 1.55 to 2.05]) in the year after loss of services, compared with those with continual obstetric services, and this was followed by a decreasing trend (-0.19 percentage points per year [95% CI, -0.25 to -0.14]). Conclusions and Relevance: In rural US counties not adjacent to urban areas, loss of hospital-based obstetric services, compared with counties with continual services, was associated with increases in out-of-hospital and preterm births and births in hospitals without obstetric units in the following year; the latter also occurred in urban-adjacent counties. These findings may inform planning and policy regarding rural obstetric services.

Beyond Clinical Complexity: Nonmedical Barriers to Nursing Home Care for Rural Residents.

We conducted a qualitative content analysis of barriers to nursing home admission for rural residents. Data came from semi-structured interviews with 23 rural hospital discharge planners across five states (Georgia, Idaho, Minnesota, Pennsylvania, and Wisconsin). From those, we identified four themes around nonmedical barriers to rural nursing home placement with particular salience in rural areas: financial issues, transportation, nursing home availability and infrastructure, and timeliness. We also identified policy and programmatic interventions across four themes: loosen bureaucratic requirements, improve communication between facilities, increase rural long-term care capacity, and address underlying social determinants of health.

Health Care Engagement and Follow-up After Perceived Discrimination in Maternity Care.

BACKGROUND: Negative experiences in the health care system, including perceived discrimination, can result in patient disengagement from health care. Four million US women give birth each year, and the perinatal period is a time of sustained interaction with the health care system, but potential consequences of negative experiences have not been examined in this context. We assessed whether perceived discrimination during the birth hospitalization were associated with postpartum follow-up care. METHODS: Data were from the Listening to Mothers III survey, a nationally drawn sample of 2400 women with singleton births in US hospitals in 2011-2012. We used multivariate logistic regression to estimate adjusted odds of having a postpartum visit in the 8 weeks following birth by perceptions of discrimination due to (1) race/ethnicity; (2) insurance type; and (3) a difference of opinion with a provider about care. RESULTS: Women who experienced any of the 3 types of perceived discrimination had more than twice the odds of postpartum visit nonattendance (adjusted odds ratio=2.28, P=0.001), after adjusting for socioeconomic and medical characteristics. CONCLUSIONS: The postpartum visit is an opportunity for a patient and clinician to address continuing health problems following birth, discuss contraception, and screen for chronic disease. Forgoing this care may have negative health effects. The findings from this study underscore the need to reduce discrimination and improve maternity care experiences.

Prenatal attitudes toward vaginal delivery and actual delivery mode: Variation by race/ethnicity and socioeconomic status.

OBJECTIVES: Researchers documenting persistent racial/ethnic and socioeconomic status disparities in chances of cesarean delivery have speculated that women's birth attitudes and preferences may partially explain these differences, but no studies have directly tested this hypothesis. We examined whether women's prenatal attitudes toward vaginal delivery differed by race/ethnicity or socioeconomic status, and whether attitudes were differently related to delivery mode depending on race/ethnicity or socioeconomic status. METHODS: Data were from the First Baby Study, a cohort of 3006 women who gave birth to a first baby in Pennsylvania between 2009 and 2011. We used regression models to examine (1) predictors of prenatal attitudes toward vaginal delivery, and (2) the association between prenatal attitudes and actual delivery mode. To assess moderation, we estimated models adding interaction terms. RESULTS: Prenatal attitudes toward vaginal delivery were not associated with race/ethnicity or socioeconomic status. Positive attitudes toward vaginal delivery were associated with lower odds of cesarean delivery (AOR=0.60, P < .001). However, vaginal delivery attitudes were only related to delivery mode among women who were white, highly educated, and privately insured. CONCLUSIONS: There are racial/ethnic differences in chances of cesarean delivery, and these differences are not explained by birth attitudes. Furthermore, our findings suggest that white and high-socioeconomic status women may be more able to realize their preferences in childbirth.

Labor induction and cesarean delivery: A prospective cohort study of first births in Pennsylvania, USA.

BACKGROUND: Mode of delivery at first childbirth largely determines mode of delivery at subsequent births, so it is particularly important to understand risk factors for cesarean delivery at first childbirth. In this study, we investigated risk factors for cesarean delivery among nulliparous women, with focus on the association between labor induction and cesarean delivery. METHODS: A prospective cohort study of 2851 nulliparous women with singleton pregnancies who attempted vaginal delivery at hospitals in Pennsylvania, 2009-2011, was conducted. We used nested logistic regression models and multiple mediational analyses to investigate the role of three groups of variables in explaining the association between labor induction and unplanned cesarean delivery-the confounders of maternal characteristics and indications for induction, and the mediating (intrapartum) factors-including cervical dilatation, labor augmentation, epidural analgesia, dysfunctional labor, dystocia, fetal intolerance of labor, and maternal request of cesarean during labor. RESULTS: More than a third of the women were induced (34.3%) and 24.8% underwent cesarean delivery. Induced women were more likely to deliver by cesarean (35.9%) than women in spontaneous labor (18.9%), unadjusted OR 2.35 (95% CI 1.97-2.79). The intrapartum factors significantly mediated the association between labor induction and cesarean delivery (explaining 76.7% of this association), particularly cervical dilatation <3 cm at hospital admission, fetal intolerance of labor, and dystocia. The indications for labor induction only explained 6.2%. CONCLUSIONS: Increased risk of cesarean delivery after labor induction among nulliparous women is attributable mainly to lower cervical dilatation at hospital admission and higher rates of labor complications.