Risk Factors For Cesarean Delivery Research Articles

Perinatal outcome of pregnancies complicated with extreme birth weights at term

Objective: The objective of this study is to investigate whether an abnormal birthweight at term, either small for gestational age (SGA, < 5th centile for gestational age) or large for gestational age (LGA, > 95th centile for gestational age), is a risk factor for perinatal complications as compared with birthweight appropriate for gestational age (AGA).Methods: A population-based retrospective cohort analysis of all singleton pregnancies delivered between 1991 and 2014 at Soroka Medical Center. Congenital malformations and multiple pregnancies were excluded. A multivariable generalized estimating equation regression model was used to control for maternal clusters and other confounders.Results: During the study period, 228,242 births met the inclusion criteria, of them 91% were AGA (n = 207,652), 4.7% SGA, and 4.3% LGA. SGA significantly increased the risk for perinatal mortality (aOR 5.6, 95%CI 4.5–6.8) and low 5-min Apgar scores (aOR 2.2, 95%CI 2.0–2.4), while LGA did not. SGA and LGA were both significant risk factors for cesarean delivery. LGA was significantly associated with shoulder dystocia and post-partum hemorrhage (aOR =13.6, 95%CI 10.9–17.0, and aOR 1.7, 95%CI 1.2–2.6, respectively).Conclusions: Extreme birthweights at term are significantly associated with adverse maternal and neonatal outcomes. As opposed to SGA, LGA is not independently associated with perinatal mortality.

Estimating Risk Factors for Cesarean Delivery in a Teenage Population [5K

INTRODUCTION: Factors such as advanced age, increased body mass index, extremes of neonatal birth weight among others are predictors of delivery via cesarean section. However, some of these predictors may not applicable to a teenage population. As such, our objective was to identify modifiable predictors for prevention of the primary cesarean delivery, in a nulliparous teen population of a tertiary care center. METHODS: We performed a retrospective cohort chart review of all teenage deliveries (≤19 years old) at one institution over a 2-year period. The inclusion criteria were all singleton births from July 2014 to July 2016 among mothers at term who delivered via non-elective cesarean section. Exclusion criteria included fetal malpresentation, presentation to prenatal care at gestational age &gt;20 weeks and pregnancies complicated by fetal anomalies. RESULTS: Of the 322 included deliveries, 14.6% delivered by non-elective C-section. The population was 90% Hispanic with a mean age of 17.7 years ± 1.31. Only neonatal birth weight was significantly associated with delivery via cesarean section in bivariate analysis and remained a predictor. Mothers of neonates with extremes of birth weights (&lt; 2500, &gt;4000 g) had higher odds of having a cesarean delivery, compared to neonates with normal birth weight (OR 4.7 95%CI 2.3 – 9.4 and OR 4.6 95% CI 1.1 – 19.4). CONCLUSION: Among adolescent nulliparous patients, birth weight of the neonate was found to be a risk factor that places the gravid teen at increased risk for cesarean delivery. Further research with a greater sample size over a 10-year period is under way.

Coding update of the SMFM definition of low risk for cesarean delivery from ICD-9-CM to ICD-10-CM

In 2015, the Society for Maternal-Fetal Medicine developed a low risk for cesarean delivery definition based on administrative claims-based diagnosis codes described by the International Classification of Diseases, Ninth Revision, Clinical Modification. The Society for Maternal-Fetal Medicine definition is a clinical enrichment of 2 available measures from the Joint Commission and the Agency for Healthcare Research and Quality measures. The Society for Maternal-Fetal Medicine measure excludes diagnosis codes that represent clinically relevant risk factors that are absolute or relative contraindications to vaginal birth while retaining diagnosis codes such as labor disorders that are discretionary risk factors for cesarean delivery. The introduction of the International Statistical Classification of Diseases, 10th Revision, Clinical Modification in October 2015 expanded the number of available diagnosis codes and enabled a greater depth and breadth of clinical description. These coding improvements further enhance the clinical validity of the Society for Maternal-Fetal Medicine definition and its potential utility in tracking progress toward the goal of safely lowering the US cesarean delivery rate. This report updates the Society for Maternal-Fetal Medicine definition of low risk for cesarean delivery using International Statistical Classification of Diseases, 10th Revision, Clinical Modification coding.

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

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. 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. 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 <3cm at hospital admission, fetal intolerance of labor, and dystocia. The indications for labor induction only explained 6.2%. 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.

Double-balloon catheter for induction of labour in women with a previous cesarean section, could it be the best choice?

IntroductionWe analysed the efficacy and safety of double-balloon catheter for cervical ripening in women with a previous cesarean section and which were the most important variables associated with an increased risk of repeated cesarean delivery.Materials and methodsWe designed an observational retrospective study of 418 women with unfavourable cervices (Bishop Score <5), a prior cesarean delivery, and induction of labour with a double-balloon catheter. Baseline maternal data and perinatal outcomes were recorded for a descriptive, bivariate, and multivariate analysis. A p value <0.05 was considered statistically significant.ResultsMost women improved their initial Bishop Score (89.5%) although only a 20.8% of them went into spontaneous active labour. Finally, 51.4% of the women achieved a vaginal delivery. Five cases of intrapartum uterine rupture (1.2%) occurred. After multivariate analysis, main risk factors for repeated cesarean section were dystocia in the previous pregnancy (OR 1.744; CI 95% 1.066–2.846), the absence of previous vaginal delivery (OR 2.590; CI 95% 1.066–6.290), suspected fetal macrosomia (OR 2.410; CI 95% 0.959–6.054), and duration of oxytocin induction period (OR 1.005; CI 95% 1.004–1.006). The area under the curve was 0.789 (p < 0.001).ConclusionsDouble-balloon catheter seems to be safe and effective for cervical ripening in women with a previous cesarean delivery and unfavourable cervix. In our study, most women could have a vaginal delivery in spite of their risk factors for cesarean delivery. A multivariate model based on some clinical variables has moderate predictive value for intrapartum cesarean section.

655: Variation in cesarean delivery rates among high-risk pregnancies across hospitals in the U.S

The rate of cesarean deliveries in the U.S. has peaked in the last decade, now reaching a level over double the upper limit deemed acceptable by the WHO. Studies have also described large unexplained variation in cesarean delivery rates between countries, states, hospitals, and physicians. Our study aims to evaluate the current variation in cesarean delivery rates between hospitals across the U.S., and to evaluate differences in hospital characteristics and high-risk pregnancy factors that could explain the higher cesarean delivery rates seen in certain hospitals. We conducted a retrospective population-based cohort study using the 2011 HCUP-NIS database. We identified all U.S. hospitals with delivery admissions and compared the hospitals with high cesarean delivery rates to those with low/mid rates, in terms of hospital and maternal characteristics, as well as neonatal and maternal outcomes. We used stratified regression to further evaluate the independent impact of each hospital characteristic and pregnancy high-risk factor on the observed disparity in cesarean delivery rates. The cesarean delivery rate in the U.S. rose steadily from 29% in 2003 to 34% in 2012. In 2011, 99% of U.S. hospitals have a cesarean delivery rate beyond 20%. The disparity in cesarean delivery rates between high and low-cesarean-delivery-rate hospitals remained after stratifying by individual hospital characteristics and individual pregnancy risk factor. Specifically, the likelihood of having a cesarean delivery in a woman with a high-risk pregnancy is two-fold (aOR 1.99, CI 1.92-2.06) if she is cared for in a hospital within the high-cesarean-delivery-rate group than in one within the low/mid-cesarean-delivery-rate group. Meanwhile, we found no significant difference in neonatal outcomes or maternal outcomes between patients delivered in a high vs. low-cesarean-delivery-rate hospital. Individual hospitals are in themselves independent risk factors for cesarean delivery, regardless of hospital location, payment source, teaching status and bed size, and regardless of patients’ pregnancy risks and characteristics. Choosing to give birth in a certain hospital can put patients at a two-fold risk of having a cesarean delivery, without benefits in maternal or neonatal outcomes.

PHS148 - France-Spain Comparison of Hospital Delivery Mode Between 2006 And 2014 According Comorbidity Profiles of Patients

The aim of the study is to compare delivery mode in hospital (vaginal and cesarean) between two European countries, according to patient’s comorbidities as diabetes, age, multiple pregnancies, obesity, and prematurity. A retrospective cohort was performed from national PMSI (France) and CMBD (Spain) public databases 2006 to 2014. Multivariate regression was done to model cesarean delivery according to comorbidities. All of childbirth hospitalizations were extracted by selecting DRG. Comorbidities were identified according to each country diagnosis classification’s (ICD 10 for France and ICD-9 for Spain). The number of annual hospitalization for childbirth is stable in France around 800,000 stays (-2% between 2006 and 2014). In the public Spain sector, we observed a decrease of 12% between 2006 and 2014 with almost 330,000 stays in 2014. The cesarean rate in 2014 is 20% in France versus 22% in Spain and increased by 2% between 2006 and 2014 for France and decreased by 12% for Spain. The median age is 30 years in 2014 for France versus 32 years for Spain and has increased by one year between 2006 and 2014 in the two countries. The standardized caesarean rate is 1% higher in Spain and + 1.2% for prematurity, and + 0.3% for multiple births. Multivariate analysis of cesarean deliveries highlights a significance of all risk factors (age, prematurity, diabetes, obesity and multiple births). The multiple pregnancy is the first risk of cesarean delivery with an OR of 5.36 (5.10-5.63) for Spain versus 3.85 (3.72-3.98) in France. The second risk is the prematurity in France with an OR of 2.03(1.98-2.08) and the diabetes in Spain with an OR of 1.90(1.81-2.00). Multiple pregnancy is the most important risk factor for cesarean delivery for Spain and France. The second risk factor is obesity for Spain and prematurity for France.

Trends in the delivery route of twin pregnancies in the United States, 2006–2013

ObjectivesTo determine the trends of cesarean delivery rate among twin pregnancies from 2006 to 2013. Study designThis is a population-based, cross-sectional analysis of twin live births from United State birth data files of the National Center for Health Statistics for calendar years 2006 through 2013. We stratified the population based on the gestational age groups, maternal race/ethnicity, advanced maternal age (AMA) which was defined by age more than 35 years and within the standard birth weight groups (group 1: birth weight 500–1499g, group 2: birth weight 1500–2499g and group 3: birth weight >2500g). We also analyzed the effect of different risk factors for cesarean delivery in twins. ResultsThere were 1,079,102 infants born of twin gestations in the U.S. from 2006 to 2013, representing a small but significant increase in the proportion of twin births among all births (3.2% in 2006 versus 3.4% in 2013). The rate of cesarean delivery in twin live births peaked at 75.3% in 2009, and was significantly lower (74.8%) in 2013. The rate of the twin live birth with the breech presentation increased steadily from 26.3% in 2006 to 29.1% in 2013. For the fetus of the twin pregnancy presented as breech, the cesarean delivery rate peaked at 92.2% in 2010, falling slightly but significantly in the ensuing 3 years. The results demonstrated that the decrease in cesarean delivery rate was due to fewer cesareans in non-Hispanic white patients; all other ethnic subgroups showed increasing rates of cesarean delivery throughout the study. Gestational diabetes, gestational hypertension, previous cesarean delivery and breech presentation were all significant risk factors for cesarean delivery during the entire study period. Induction of labor and premature rupture of the membranes were associated with lower rates of cesarean delivery in twins. ConclusionThe recent decrease in the cesarean delivery rate in twin gestation appears to be largely attributable to a decline in cesarean among pregnancies complicated by breech presentation in non-Hispanic white women, and may reflect a health care disparity that deserves further research.

Outcome and risk factors of cesarean delivery with and without cesarean myomectomy in women with uterine myomatas.

To evaluate the outcome of a cesarean myomectomy (CM) versus a cesarean delivery (CD) alone in women with uterine myomas and the risk factors for adverse outcomes. A retrospective cohort study of all women undergoing CDs with uterine leiomyomatas and singleton pregnancies was performed. Patients with known risk factors for hemorrhage were excluded. Measured adverse outcome parameters included estimated blood loss, drop in hemoglobin levels (pre/postoperatively), operation time, and the use of additional uterotonics. Outcome parameters of women with CM were compared to women with CD alone. Possible risk factors for adverse outcomes were analyzed in a multivariate regression analysis. Evaluated risk factors for CM were according to localization and type of myomatas, the myoma size, BMI ≥30kg/m2, age ≥40years, fetal weight ≥4kg, repeat CD, and unplanned CD in the first stage of labor. The influence of localization and myoma type were further analyzed in a subgroup analysis. Of the 162 women with uterine myomatas during CD, 48 underwent CM and were analyzed. Overall, CM was not associated with adverse outcomes. Independent of a concomitant myomectomy, a large myoma size of ≥5cm was associated with an increased blood loss of ≥500ml (adj. OR 2.7 CI 95% 1.2-6.2, p=0.02), and women ≥40years of age had a significant postoperative drop in hemoglobin (adj. OR 2.4 CI 95% 1.0-5.4, p=0.04). In the univariate subgroup analysis, CM of multiple myomatas was associated with an increased blood loss and an increased operation time compared to women with multiple myomatas and CD alone. Prolonged operation times were also observed in women with pedunculated and subserosal myomatas with concomitant myomectomy. There were no cases of hysterectomy or blood transfusions. CM performed by an experienced obstetrician can be safe in selected patients who are without additional preexisting risk factors. Risk factors that are associated with increased blood loss in women with uterine leiomyomatas include a larger size of the leiomyoma (≥5cm) and a maternal age of ≥40years.

Indications for primary cesarean delivery relative to body mass index

Obesity is a known risk factor for cesarean delivery. Limited data are available regarding the reasons for the increased rate of primary cesarean in obese women. It is important to identify the factors leading to an increased risk of cesarean to identify opportunities to reduce the primary cesarean rate. We evaluated indications for primary cesarean across body mass index (kg/m(2)) classes to identify the factors contributing to the increased rate of cesarean among obese women. In the Consortium of Safe Labor study from 2002 through 2008, we calculated indications for primary cesarean including failure to progress or cephalopelvic disproportion, nonreassuring fetal heart tracing, malpresentation, elective, hypertensive disease, multiple gestation, placenta previa or vasa previa, failed induction, HIV or active herpes simplex virus, history of uterine scar, fetal indication, placental abruption, chorioamnionitis, macrosomia, and failed operative delivery. For women with primary cesarean for failure to progress or cephalopelvic disproportion, dilation at the last recorded cervical examination was evaluated. Women were categorized according to body mass index on admission: normal weight (18.5-24.9), overweight (25.0-29.9), and obese classes I (30.0-34.9), II (35.0-39.9), and III (≥40). Cochran-Armitage trend test and χ(2) tests were performed. Of 66,502 nulliparous and 76,961 multiparous women in the study population, 19,431 nulliparous (29.2%) and 7329 multiparous (9.5%) women underwent primary cesarean. Regardless of parity, malpresentation, failure to progress or cephalopelvic disproportion, and nonreassuring fetal heart tracing were the common indications for primary cesarean. Regardless of parity, the rates of primary cesarean for failure to progress or cephalopelvic disproportion increased with increasing body mass index (normal weight, overweight, and classes I, II, and III obesity in nulliparous women: 33.2%, 41.6%, 46.4%, 47.4%, and 48.9% [P < .01] and multiparous women: 14.5%, 20.3%, 22.8%, 27.2%, and 25.3% [P<.01]), whereas the rates for malpresentation decreased (normal weight, overweight, and classes I, II, and III obesity in nulliparous women: 23.7%, 17.2%, 14.6%, 12.0%, and 9.1% [P < .01] and multiparous women: 35.6%, 30.6%, 26.5%, 24.3%, and 22.9% [P < .01]). Rates of primary cesarean for nonreassuring fetal heart tracing were not statistically different for nulliparous (P > .05) or multiparous (P > .05) women. Among nulliparous women who had a primary cesarean for failure to progress or cephalopelvic disproportion, rates of cesarean prior to active labor (6 cm) increased as body mass index increased, accounting for 39.3% of women with class I, 47.1% of women with class II, and 56.8% of women with class III obesity compared to 35.2% for normal-weight women (P < .01). Similar to normal-weight women, the indication of cesarean for failure to progress or cephalopelvic disproportion was the major factor contributing to the increase in primary cesarean in obese women, but was even more prevalent with increasing obesity class. The rates of intrapartum primary cesarean prior to achieving active labor increased with increasing obesity class in nulliparous women.

Maternal obesity and Caesarean delivery in sub-Saharan Africa.

To quantify maternal obesity as a risk factor for Caesarean delivery in sub-Saharan Africa. Multivariable logistic regression analysis using 31 nationally representative cross-sectional data sets from the Demographic and Health Surveys (DHS). Maternal obesity was a risk factor for Caesarean delivery in sub-Saharan Africa; a clear dose-response relationship (where the magnitude of the association increased with increasing BMI) was observable. Compared to women of optimal weight, overweight women (BMI 25-29 kg/m(2) ) were significantly more likely to deliver by Caesarean (OR: 1.54; 95% CI: 1.33, 1.78), as were obese women (30-34.9 kg/m(2) (OR: 2.39; 95%CI: 1.96-2.90); 35-39.9 kg/m(2) (OR: 2.47 95%CI: 1.78-3.43)) and morbidly obese women (BMI ≥40 kg/m(2) OR: 3.85; 95% CI: 2.46-6.00). BMI is projected to rise substantially in sub-Saharan Africa over the next few decades and demand for Caesarean sections already exceeds available capacity. Overweight women should be advised to lose weight prior to pregnancy. Furthermore, culturally appropriate prevention strategies to discourage further population-level rises in BMI need to be designed and implemented.

Cesarean Delivery in Adolescents

Rates of cesarean delivery among low risk women of all ages have risen markedly over the past two decades, and adolescents are not immune to this trend. In subsequent pregnancies, nearly 90% of these women will deliver by repeat cesarean, which carries significant risks of maternal and infant morbidity and mortality secondary to adhesive disease, abnormal placentation and uterine rupture. To date, understanding of risk factors for cesarean delivery in adolescents is limited, and we therefore sought to examine how adolescent maternal age affects indication for primary cesarean delivery in a cohort of nulliparous women delivering vertex presenting singletons at term. This was a retrospective cohort study in an urban academic tertiary care center evaluating age related risk factors for, and characteristics of, mode of delivery for nulliparous women delivering vertex-presenting singletons at term. Adolescents were half as likely to undergo cesarean delivery overall (OR=0.48; 95%CI 0.43, 0.54), and more than one third less likely to undergo cesarean delivery in labor (OR=0.59; 95%CI 0.53, 0.66). Adjustment for potential confounders did not alter the strength of these associations. Adolescents were half as likely to undergo cesarean delivery for failure to progress (OR=0.49, 95%CI 0.43-0.54). There was no difference in the odds of cesarean delivery for non-reassuring fetal status (OR=0.91, 95%CI 0.77-1.06), nor genital herpes (OR=1.44, 95%CI 0.57-3.68). Induction, macrosomia, oxytocin augmentation and any labor complication were all associated with increased risk of cesarean delivery. There was no difference in the duration of second stage for adolescents who delivered by cesarean delivery compared with adults (240.0 vs. 237.7 minutes, p=0.84), but those adolescents who delivered vaginally had a second stage that was one third shorter than adults (62.5 vs 100.3 minutes, p<0.001). Adolescents are half as likely to undergo primary cesarean delivery overall, and 40% less likely to undergo a primary cesarean delivery in labor, even after adjustment for multiple maternal, neonatal and labor characteristics. This difference is not explained by differences in the duration of the second stage of labor.

Investigating into whether systematic fetal weight estimation by ultrasound in the delivery room increases the risk of cesarean delivery

L’échographie est un précieux outil utilisé quotidiennement en salle de travail. Ses applications sont multiples. L’objectif est d’évaluer si le recours systématique à une estimation échographique du poids fœtal et en salle de naissances augmente le risque d’accouchement par césarienne. Etude de cohorte monocentrique. Nous avons inclus toutes les parturientes avec des grossesses monofœtales qui avaient accouché à un terme ≥ 39 SA. Nous avons exclu toutes les patientes avec une contre indication à l'accouchement par voie basse ainsi que celles chez lesquelles une Estimation échographique du poids fœtal (EEPF) le jour de l'accouchement était jugée nécessaire à la prise de décision obstétricale. Les parturientes ainsi retenues ont été réparties en deux groupes: - G1 : parturientes ayant systématiquement eu une EEPF - G2: parturientes n’ayant pas eu cette EEPF. Nous avons comparé le taux d’accouchement par césarienne avec ajustement sur les potentiels facteurs confondants selon la régression logistique. 838 parturientes ont été retenues pour ce travail. La primiparité, l'EEPF ainsi que le poids à la naissance étaient des facteurs de risque d'accouchement par césarienne. Après ajustement aux facteurs confondants, l'EEFP réalisée systématiquement dans G1 s'est révélé être un facteur de risque indépendant d'accouchement par césarienne avec un OR =3,8 (IC95% = [2,67-5,48]). Ce risque augmentait significativement avec le poids estimé (PFE): OR=2,27(IC95;1,15-4,47;p=0.018) pour 3500 < PFE< 4000g et OR= 10,64(IC95; 4,28-26,41;p<0.001) pour PFE>4000g. L’EEPF réalisée systématiquement en salle de naissances représente un facteur de risque indépendant et potentiellement modifiable d’accouchement par césarienne.

350: A fetal head circumference above the 90th centile is a significant risk factor for cesarean delivery and complicated labor: results from the prospective multi-center Genesis Study

350: A fetal head circumference above the 90th centile is a significant risk factor for cesarean delivery and complicated labor: results from the prospective multi-center Genesis Study

409: Increased fetal adiposity is a risk factor for cesarean delivery - Results of the national prospective Genesis Study

409: Increased fetal adiposity is a risk factor for cesarean delivery - Results of the national prospective Genesis Study

Predicting Cesarean Delivery After Induction of Labor Among Nulliparous Women at Term.

To identify independent risk factors for cesarean delivery after induction of labor and to develop a nomogram for predicting cesarean delivery among nulliparous women undergoing induction of labor at term. This is a retrospective cohort study including nulliparous women with singleton, term (37 0/7 weeks of gestation or greater), cephalic pregnancies undergoing induction of labor from July 1, 2006, through May 31, 2012, at a tertiary care academic center. Inductions were identified using International Classification of Diseases, 9th Revision codes. Demographic, delivery, and outcome data were abstracted manually from the medical record. Women with a contraindication to vaginal delivery (malpresentation, abnormal placentation, prior myomectomy) were excluded. Independent risk factors for cesarean delivery were identified using logistic regression. During the study period, there were 785 nulliparous inductions that met study criteria; 231 (29.4%) underwent cesarean delivery. Independent risk factors associated with an increased risk of cesarean delivery included older maternal age, shorter maternal height, greater body mass index, greater weight gain during pregnancy, older gestational age, hypertension, diabetes mellitus, and initial cervical dilation less than 3 cm. A nomogram was constructed based on the final model with a bias-corrected c-index of 0.709 (95% confidence interval 0.671-0.750). We identified independent risk factors that can be used to predict cesarean delivery among nulliparous women undergoing induction of labor at term. If validated in other populations, the nomogram could be useful for individualized counseling of women with a combination of identifiable antepartum risk factors. II.

Surgical Site Infection following Cesarean Delivery: Patient, Provider, and Procedure-Specific Risk Factors.

This study aims to identify risk factors for cesarean delivery (CD) surgical site infection (SSI). study design: Retrospective analysis of 2,739 CDs performed at the University of Pittsburgh in 2011. CD SSIs were defined using National Healthcare Safety Network (NHSN) criteria. Chi-square test and t-test were used for bivariate analyses and multivariate logistic regression was used to identify SSI risk factors. Of 2,739 CDs, 178 (6.5%) were complicated by SSI. Patients with a SSI were more likely to have Medicaid, have resident physicians perform the CD, an American Society of Anesthesiologists (ASA) class of ≥ 3, chorioamnionitis, tobacco use, and labor before CD. In multivariable analysis, labor (odds ratio [OR], 2.35; 95% confidence interval [95% CI], 1.65-3.38), chorioamnionitis (OR, 2.24; 95% CI, 1.25-3.83), resident teaching service (OR, 2.15; 95% CI, 1.54-3.00), tobacco use (OR, 1.70; 95% CI, 1.04-2.70), ASA class ≥ 3 (OR, 1.61; 95% CI, 1.06-2.39), and CDs performed for nonreassuring fetal status (OR, 0.43; 95% CI, 0.26-0.67) were significantly associated with CD SSI. Multiple patient, provider, and procedure-specific risk factors contribute to CD SSI risk which may be targeted in infection-control efforts.

OP04.03: Mid‐pregnancy cervical length as a risk factor for Caesarean delivery in twin pregnant women

OP04.03: Mid‐pregnancy cervical length as a risk factor for Caesarean delivery in twin pregnant women

Hospital variation in cesarean delivery rates: contribution of individual and hospital factors in Florida

Primary cesarean deliveries are a major contributor to the large increase in cesarean delivery rates in the United States over the past 2 decades and are an essential focus for the reduction of related morbidity and costs. Studies have shown that primary cesarean delivery rates among low-risk women in the United States vary 3-fold across hospitals and are not explained by differences in patient case-mix. However, the extent to which maternal vs hospital characteristics contribute to this variation remains poorly understood because previous studies were limited in scope and did not assess the influence of factors such as maternal ethnicity subgroups or prepregnancy obesity. We assessed the contribution of individual- and hospital-level risk factors to the hospital variation in primary cesarean delivery rates among low-risk women in Florida. Our population-based retrospective cohort study used Florida's linked birth certificate and hospital discharge records for the period of 2004-2011. The study population was comprised of 412,192 nulliparous, singleton, vertex, live births with labor at 37-40 weeks gestation in 122 nonmilitary delivery hospitals. Data were analyzed with logistic mixed-effects regression with cesarean delivery as the outcome. This approach provided adjusted risk estimates at an individual and hospital level and the estimated percent of hospital variation statewide that was explained by these factors. The primary cesarean delivery rate in the study population was 23.9%, with hospital-specific estimates that ranged from 12.8-47.3%. Leading risk factors for cesarean delivery were maternal age ≥35 years (adjusted relative risk, 2.22), prepregnancy obesity (body mass index, ≥30 kg/m(2); adjusted relative risk, 1.73), medical risk conditions (adjusted relative risk, 1.72), labor induction (adjusted relative risk, 1.52), and delivery in hospitals located in Miami-Dade County (adjusted relative risk, 1.73). Hospital geographic location was a significant effect modifier for prepregnancy obesity, medical conditions, and labor induction (P < .05), with a tendency towards lower adjusted relative risks for these factors in Miami-Dade County relative to other Florida regions. Conversely, Miami-Dade County had an increased prevalence of higher-risk ethnic subgroups, such as Cuban or Puerto Rican mothers, and also substantially higher adjusted relative risks that were associated with practice-related factors, such as delivery during weekday hours. Whereas hospital geographic location contributed to 39.6% of the observed variation statewide, the estimated contribution of maternal ethnicity ranged from 1.6-15.7% among Florida regions. Hospital geographic location contributes to hospital variation in primary cesarean delivery rates among low-risk women in Florida. In contrast to previous studies, our findings suggest that individual level risk factors such as maternal ethnicity also contribute to some of this variation, with differing extent by region. These individual factors likely interact with practice factors and add to the variation. This study was limited by not including maternal Bishop score before induction or obstetrics provider in the analysis. These were not available on the dataset but likely contribute to the variation. Our findings suggest potential issues to consider in quality improvement efforts, such as the need for future qualitative research that focuses on mothers in higher-risk ethnic subgroups and providers in high-rate hospitals, particularly those in Miami-Dade County. These studies may help to identify potential cultural differencesin maternal beliefs and expectations for delivery and maternal reasons for differences in obstetrics practices.

Influence of obesity on route of delivery in a population of African descent in Martinique.

To determine whether obesity is an independent risk factor for cesarean delivery in Martinique. A retrospective study was performed using data for deliveries that occurred at the University Hospital of Fort de France between January and September 2010. Women were divided into four groups on the basis of body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters; < 25 [group 1], 25-29 [group 2], 30-39 [group 3], and ≥ 40 [group 4]). Independent risk factors for cesarean delivery were identified through multivariate analysis. Overall, 1286 women were included. Mean weight gain was lower in groups 2 (9.9 kg, 95% CI 9.2-10.7), 3 (5.7 kg, 4.7-6.7), and 4 (1.0 kg,-1.5 to 3.5), than in group 1 (12.3 kg, 11.9-12.7; P < 0.001 for all). In univariate analysis, cesarean deliveries were more frequent among nulliparous women in group 2 (P = 0.007) and group 3 (P = 0.053) than among those in group 1. In multivariate analysis, BMI was not associated with cesarean delivery (BMI 25-29: adjusted odds ratio 0.64, 95% CI 0.33-1.25; BMI ≥ 30: 0.61, 0.29-1.39). Obesity was not an independent risk factor for cesarean delivery. Weight control and a positive attitude towards trial of labor in obese women could have led to the findings.