Cesarean Risk Research Articles

Associations of maternal asthma severity and control with pregnancy complications

Objectives: To assess the associations of maternal asthma severity and control with pregnancy-induced hypertension (PIH), gestational diabetes and cesarean delivery. Methods: A cohort of 41 660 pregnancies from women with and without asthma who delivered between 1990 and 2002 was constructed by linking Québec’s administrative databases. Maternal asthma was defined by at least one asthma diagnosis and one dispensed prescription for an asthma medication in the 2 years before or during pregnancy. Asthma severity and control were assessed using validated indexes during the entire pregnancy to study cesarean delivery and 1-year prior to week 20 of gestation to study PIH and gestational diabetes. Generalized Estimation Equation models were used to obtain odds ratios (OR) for PIH, gestational diabetes and cesarean in association with maternal asthma severity and control. Results: Almost one-third of the women had uncontrolled asthma and up to 5% had severe asthma. Severe asthma increased the risk of cesarean delivery (OR = 1.35; 95% CI: 1.11–1.63) compared with mild asthma, but no association was found between asthma severity and the other outcomes. The level of asthma control was not associated with any of the outcomes, except for a near-significant increased risk of PIH among uncontrolled women (OR = 1.18; 95% CI: 0.97–1.42). Conclusions: The risk of gestational diabetes was not associated with asthma severity or control, and the risk of PIH was not associated with asthma severity. However, further studies are needed to clarify the association between asthma control and PIH. The increased risk of cesarean among women with severe asthma may be explained by the physician’s and patient’s concerns over the safety of normal delivery.

293: Gestational weight gain after the diagnosis of gestational diabetes: association with adverse outcomes

293: Gestational weight gain after the diagnosis of gestational diabetes: association with adverse outcomes

Term induction of labor and risk of cesarean delivery by parity

Objective: To evaluate the risk of cesarean delivery among both nulliparous and multiparous women undergoing a term induction of labor compared to women that present in spontaneous labor at term.Methods: We performed a retrospective cohort study of term (≥37 weeks) singleton pregnancies between 2005 and 2010 comparing women that had an induction to those that presented in spontaneous labor. Multiparity was defined as a prior delivery after 20 weeks’ gestation. Chi-square was used to compare categorical variables. Multivariable logistic regression was used to control for confounders. Analyses were stratified by parity.Results: 863 women were included in the analysis. There were 605 inductions (cesarean rate 23%) and 257 spontaneous labor (cesarean rate 7%), OR 3.4, 95% CI [2.1–5.4]. Stratified by parity, nulliparas undergoing induction had an increased cesarean rate compared to spontaneous labor (27% versus 11%, OR 3.13, 95% CI [1.76–5.57]) as did multiparas (13% versus 3%, OR 4.04, 95% CI [1.36–11.94]). This increased risk for cesarean after induction remained in both nulliparous and multiparous women even after controlling for confounders (aOR 2.90, 95% CI [1.60–5.25] and aOR 3.47, 95% CI [1.12–10.67], respectively). Neither starting cervical exam nor indication for induction altered this increased risk.Conclusions: The increased risk of cesarean in women undergoing an induction is present regardless of parity and indication for induction. This should be taken into account when counseling women regarding risks of induction, regardless of parity. Future studies should focus on other clinical characteristics of induction that may mitigate this risk.

Prior Cesarean Delivery and Risk of Conversion to Laparotomy During Laparoscopic Hysterectomy

Abstract Objective: The goal of this study was to test the hypothesis that a history of previous cesarean delivery does not increase the risk of conversion to laparotomy in patients undergoing laparoscopic supracervical hysterectomy (LSH) for benign gynecologic indications. Design: This was a retrospective cohort study. Materials and Methods: A retrospective cohort study was conducted of 799 patients who underwent LSH for benign gynecologic indications between January 2003 and December 2009. Results: There were a total of 16 (2%) conversions. The patients who underwent conversion were 5 times more likely to have a uterus that weighed ≥250 g (odds ratio [OR]: 5.2; 95% confidence interval [CI]: 1.8–17.4) and 3 times more likely to have had previous cesarean delivery (OR: 3.0; 95% CI: 1.1–8.0). These patients were also significantly more likely to need concomitant adhesiolysis in addition to the primary procedure (OR: 3.5; 95% CI: 1.2–9.8). However, after controlling for confounders (body mass index, blood l...

Diet or medically treated gestational diabetes: is there any difference for obstetrical and neonatal complications? A French cohort study

The aim of the present study was to determine specific obstetrical and neonatal complications associated with diet-treated gestational diabetes (DTGD) and medically treated gestational diabetes (MTGD). This is a prospective cohort study of women followed in the Robert Debré Hospital (France, Paris) and who have given birth between 1 January, 2004, and 19 November, 2010. Clinical, biological, maternal and neonatal data were reported in the maternity database. Associations between obstetrical and neonatal complications and gestational diabetes were evaluated by estimating odd ratios (ORs) and their 95% CIs, using a logistic regression model. 16,244 pregnancies were included in the study. 1515 (9.3%) women had gestational diabetes: 1108 (7.3%) had DTGD, 243 (1.7%) had MTGD. After full adjustment, MTGD was associated with an increased risk of nonscheduled cesarean (ORnonscheduled=2.3; 95% CI: 1.6-3.3; P<0.001) while DTGD was not (ORnonscheduled=1.0; 95% CI: 0.8-1.3; P<0.96). Clinical macrosomia was positively associated with DTGD (OR=2; 95% CI: 1.7-2.4; P<0.0001) or MTGD (OR=2.9; 95% CI: 2.1-3.9; P<0.0001). This study confirms that macrosomia is the main complication of DTGD. By contrast, DTGD was not associated with neonatal hypoglycemia and cesarean, while these complications were associated with MTGD.

Uterine leiomyomata and cesarean birth risk: a prospective cohort with standardized imaging

PurposeTo determine if women with leiomyomata detected using uniform ultrasound methods are at increased risk of cesarean birth, without regard to indication. MethodsWomen were enrolled in Right from the Start (2000–2010), a prospective pregnancy cohort. Leiomyomata were counted, categorized, and measured during first trimester ultrasounds. Women provided information about demographics and reproductive history during first trimester interviews. Route of delivery was extracted from medical records or vital records, if the former were unavailable. Generalized estimating equations were used to calculate risk ratios (RR) and 95% confidence intervals (CIs) for the risk of cesarean birth by leiomyoma presence and characteristics. ResultsAmong 2635 women, the prevalences of leiomyomata and cesarean birth were 11.2% and 29.8%, respectively. Women with leiomyomata, compared with those without, had a 27% increase in cesarean risk (RR, 1.27; CI, 1.17–1.37). The association was weaker following adjustment for maternal body mass index and age (adjusted risk ratio [ARR], 1.11; CI, 1.02–1.20). The adjusted risk was elevated for women with a single leiomyoma 3 cm or more in diameter (ARR, 1.22; CI, 1.14–1.32) and women with the largest total leiomyoma volumes (ARR, 1.59; CI, 1.44–1.76). ConclusionsWomen with leiomyomata were at increased risk for cesarean birth particularly, those with larger tumor volumes.

Quantification of risk of emergency caesarean during labour after one previous caesarean section

In its 2007 guideline, the Royal College of Obstetricians and Gynaecologists (RCOG) recommends vaginal birth after caesarean (VBAC) as safer than repeat elective caesarean sections. However, this document does not give details of risk of emergency caesarean section for women accepting VBAC. An emergency caesarean is associated with increased maternal and neonatal morbidity, and women do consider the eventuality of emergency delivery when deciding mode of delivery. We sought to quantify this risk by designing a retrospective cohort study in a consultant-led unit. While higher than average rates of successful planned VBAC were achieved, the odds of emergency caesarean delivery were increased in women undergoing VBAC (OR 3.0, 95% CI 1.2–7.6, p = 0.03). Odds of requiring a Category 1 emergency caesarean were markedly raised. Our data adds to the VBAC literature by quantifying the risk of Category 1 or 2 emergency caesarean section for women entering labour who have delivered by caesarean section once previously, giving the odds of emergency caesarean section on entering labour compared with women without a scar. This gives further information to those counselling women about birth after caesarean section.

An Obstetrics Catastrophe Internal Bleeding Following Caesarean Section

The objective of this study was to find out the incidence ,indication of primary caesarean section, risk factor, place and expatriation of the primary surgeon and outcome of the cases suffering from internal bleeding following caesarean section in Chittagong Medical College Hospital. This is a prospective observational study carried out in the department of Obstetrics and gynaecology in Chittagong Medical College Hospital from September 2011 to Feb 2012. Over a period of September 2011-Feb 2012 total 11 cases were reported as internal bleeding. Among them 3 patient underwent primary surgery in this institution and 8 patient were referred from outside as internal bleeding following caesarean section. Relaparotomy was done in 10 cases after resuscitation. One patient died before operation. Abdominal cavity was full with huge clotted and non clotted blood in all cases. Bilateral broad ligament hematoma in 45.45% cases. Loosening and disruption of uterine incision in 27.27% cases. Sprouting vessel from mesentery in 9.09% cases. Bleeding from mesenteric vessels in 9.09% cases. Main surgeries performed were subtotal hysterectomy in 36.27% cases. Total abdominal hysterectomy were done in 18.11% cases. Exploration of haematoma and coagulation of sprouting mesenteric vessels with peritoneal toileting in 18.11% cases. Resuturing of uterine incision in 18.11% cases. 63.63% patients were needed ICU support. 45.45% patients died following internal bleeding after caesarean section due to irreversible shock. Though caesarean section is a common obstetrics practice now a days and a life saving procedure for the mother and child but sometimes it complicates as life threatening situation. Repeat laparotomy required in 10 cases within last 6 consecutive month in gynae unit-III in this institution. Case fatality rate was high 45.45%. Near miss mortality was also common. Majority of these were preventable. Identification of risk factor, adequate knowledge about pelvic anatomy, proper attention during primary surgery, expert decision, early diagnosis, prompt intervention and proper case management during laparotomy may improve the outcome. JCMCTA 2013; 24 (1):58-63

Racial and ethnic differences in primary, unscheduled cesarean deliveries among low-risk primiparous women at an academic medical center: a retrospective cohort study

BackgroundCesarean sections are the most common surgical procedure for women in the United States. Of the over 4 million births a year, one in three are now delivered in this manner and the risk adjusted prevalence rates appear to vary by race and ethnicity. However, data from individual studies provides limited or contradictory information on race and ethnicity as an independent predictor of delivery mode, precluding accurate generalizations. This study sought to assess the extent to which primary, unscheduled cesarean deliveries and their indications vary by race/ethnicity in one academic medical center.MethodsA retrospective, cross-sectional cohort study was conducted of 4,483 nulliparous women with term, singleton, and vertex presentation deliveries at a major academic medical center between 2006–2011. Cases with medical conditions, risk factors, or pregnancy complications that can contribute to increased cesarean risk or contraindicate vaginal birth were excluded. Multinomial logistic regression analysis was used to evaluate differences in delivery mode and caesarean indications among racial and ethnic groups.ResultsThe overall rate of cesarean delivery in our cohort was 16.7%. Compared to White women, Black and Asian women had higher rates of cesarean delivery than spontaneous vaginal delivery, (adjusted odds ratio {AOR}: 1.43; 95% CI: 1.07, 1.91, and AOR: 1.49; 95% CI: 1.02, 2.17, respectively). Black women were also more likely, compared to White women, to undergo cesarean for fetal distress and indications diagnosed in the first stage as compared to the second stage of labor.ConclusionsRacial and ethnic differences in delivery mode and indications for cesareans exist among low-risk nulliparas at our institution. These differences may be best explained by examining the variation in clinical decisions that indicate fetal distress and failure to progress at the hospital-level.

Elevated maternal lipids in early pregnancy are not associated with risk of intrapartum caesarean in overweight and obese nulliparous women

BackgroundMaternal overweight and obesity are associated with slower labour progress and increased caesarean delivery for failure to progress. Obesity is also associated with hyperlipidaemia and cholesterol inhibits myometrial contractility in vitro. Our aim was, among overweight and obese nulliparous women, to investigate 1. the role of early pregnancy serum cholesterol and 2. clinical risk factors associated with first stage caesarean for failure to progress at term.MethodsSecondary data analysis from a prospective cohort of overweight/obese New Zealand and Australian nullipara recruited to the SCOPE study. Women who laboured at term and delivered vaginally (n=840) or required first stage caesarean for failure to progress (n=196) were included. Maternal characteristics and serum cholesterol at 14–16 weeks’ of gestation were compared according to delivery mode in univariable and multivariable analyses (adjusted for BMI, maternal age and height, obstetric care type, induction of labour and gestation at delivery ≥41 weeks).ResultsTotal cholesterol at 14–16 weeks was not higher among women requiring first stage caesarean for failure to progress compared to those with vaginal delivery (5.55 ± 0.92 versus 5.67 ± 0.85 mmol/L, p= 0.10 respectively). Antenatal risk factors for first stage caesarean for failure to progress in overweight and obese women were BMI (adjusted odds ratio [aOR (95% CI)] 1.15 (1.07-1.22) per 5 unit increase, maternal age 1.37 (1.17-1.61) per 5 year increase, height 1.09 (1.06-1.12) per 1cm reduction), induction of labour 1.94 (1.38-2.73) and prolonged pregnancy ≥41 weeks 1.64 (1.14-2.35).ConclusionsElevated maternal cholesterol in early pregnancy is not a risk factor for first stage caesarean for failure to progress in overweight/obese women. Other clinically relevant risk factors identified are: increasing maternal BMI, increasing maternal age, induction of labour and prolonged pregnancy ≥41 weeks’ of gestation.

Re: Predicting successful vaginal birth after Cesarean section using a model based on Cesarean scar features examined by transvaginal sonography. O. Naji, L. Wynants, A. Smith, Y. Abdallah, C. Stalder, A. Sayasneh, A. McIndoe, S. Ghaem-Maghami, S. Van Huf

Linked Comment: Ultrasound Obstet Gynecol 2013:41:672–678 In this issue of the Journal, Naji et al. suggest a prognostic model for the likelihood of successful VBAC, constructed using a single-center sample of 131 women with VBAC planned at ≥ 38 gestational weeks. The outcome measure for this model is successful vaginal delivery and the predictors comprised maternal age, prior successful VBAC, residual myometrial thickness (RMT) in the second trimester and change in RMT from the first to the second trimester (ΔRMT). The authors should be congratulated for having conducted a methodologically rigorous study using appropriate statistical analyses. However, the rationale for such a model and its construction is not obvious and several issues should be borne in mind when considering the take-home message(s) of this work. First, do we wish to predict the failure to deliver vaginally and the resulting morbidity of an emergency Cesarean section or the risk of acute uterine rupture and its undisputed morbidity and mortality for both the mother and newborn? The latter is quite rare and poorly reported in most studies, including the present one, in which uterine rupture was defined as a full-thickness separation of the uterine wall and overlying serosa observed at Cesarean section, regardless of the causal relationship of this finding with maternal and fetal distress. Naji et al. chose to predict VBAC, thereby questionably classifying emergency Cesarean section during labor as an adverse event, regardless of the cause. However, they cleverly investigated the impact of a physician or patient's level of tolerance to the risk of emergency Cesarean on the model-based decision using decision curves, suggesting overall superiority of a model-based decision with mode of delivery as the outcome of interest. Second, in routine obstetrics, a constant goal is to refine the appraisal of future risks. A model therefore aims to predict a complication that may occur, and the choice of covariates to predict this outcome is of crucial importance. In their article, Naji et al. suggest a model based upon first- and second-trimester measurements of RMT together with two simple demographic covariates as predictors for a successful VBAC. In their population, this model was strikingly discriminative, with an area under the model-associated receiver–operating characteristics curve of 0.96, indicating that one should be able to discriminate with very high confidence (i.e. with a very low false-positive rate) those patients who will eventually require a Cesarean section for any reason during labor. This result should be interpreted with caution, as it suggests that this set of covariates strongly determines the occurrence of any peripartum complication, such as arrested cervical dilatation and fetal distress. Moreover, in the final multivariable model, prior VBAC was found to be statistically non-significant, emphasizing the potential role of RMT as the sole determinant of successful VBAC. Although the quality of the scar tissue may be related to arrested dilatation and fetal distress, it cannot be expected that ultrasound scar characteristics in the first and second trimesters explain all possible complications that can occur during labor in VBAC attempts. Third, the interpretation and generalization of results does not depend solely on the choice of outcome, covariates and study population; it also depends on variations in local practice. For example, in the study of Naji et al., 17/121 (14%) women attempting VBAC were induced using prostaglandins, with a visible effect on the outcome, yielding 9/17 subsequent emergency Cesarean sections. Such practice is not universal and would be contraindicated in some centers. Conversely, as expected, successful VBAC was associated with spontaneous onset of labor. Similarly, breech presentation and low-lying placenta may be considered contraindications for VBAC, if not for vaginal birth altogether. Nonetheless, breech and placenta previa accounted for 10.7% of the Cesarean sections performed during labor in the present study. More subtle parameters, such as the opinion of the obstetrician regarding VBAC and elective repeat Cesarean section, are difficult to measure, but are likely to affect the results. These reasons make validation in external populations mandatory and might explain failure of the validation process if this were to occur. This work shows the potential impact on the outcome of VBAC of measurement of RMT by transvaginal ultrasound in the first and second trimesters. This finding adds to our understanding of the mechanisms that underlie obstetric complications in VBAC and, in the future, should help in refining the path of care of women with prior Cesarean section. However, as the authors themselves acknowledge, it would be inappropriate to implement this model in routine practice without further validation. Not only should the model itself be validated but also its impact on public health outcomes in large populations should be investigated in an evidence-based process. J. Stirnemann Obstetrics and Maternal Fetal Medicine, Hôpital Necker–Enfants Malades, AP-HP, Paris, France; Applied Mathematics, MAP5, UMR CNRS 8145 Université Paris Descartes, Paris, France (e-mail: j.stirnemann@gmail.com)

Adverse obstetrical and neonatal outcomes in elective and medically indicated inductions of labor at term

Objective: To compare the adverse neonatal and maternal outcomes after medically indicated and elective labor induction. Both induction groups were also compared to women with spontaneous onset of labor.Method: Retrospective cohort study of 13 971 women with live, cephalic singleton pregnancies who delivered at term (from 1997 to 2007). Adverse maternal and neonatal outcomes were compared between women who underwent an induction of labor in the presence and absence of standard medical indications.Results: Among 5090 patients with induced labor, 2059 (40.5%) underwent elective labor inductions, defined as inductions without any medical or obstetrical indication. Risks of cesarean or instrumental delivery, postpartum hemorrhage >500 ml, prolonged maternal hospitalization >6 days, Apgar<7 at 5 min of life, arterial umbilical cord pH<7.1, admission in neonatal intensive care unit (NICU) and prolonged NICU hospitalization >7 days were similar between nulliparous who underwent elective and medical labor induction. Similar results were obtained for multiparous. All the above mentioned risks, but the Apgar<7 at 5 min of life, were significantly increased after induction in comparison to spontaneous labor.Conclusion: Elective induction of labor carries similar obstetrical and neonatal risks as a medically indicated labor induction. Thus, elective induction of labor should be strongly discouraged.

Caesarean delivery and risk of developing atopic diseases in children

Caesarean delivery and risk of developing atopic diseases in children

Caesarean Risk Factors in Northern Region of Bangladesh: A Statistical Analysis

Purpose: To explore the measurement of a scale of caesarean (C-section) risk factors and degree of risk contribution in different health facilities and to determine a suitable graphical representation (image) of caesarean cases.Methods: Based on seventeen indicators, a composite index was computed for each respondent and classified into three groups using Beta distribution of first kind. For the analysis of contribution of risk factors between private and public patients, principal component analysis (PCA) was also used. An attempt was made to visualise a suitable graphical representation of caesarean cases by independent component analysis (ICA).Results: The selected risk factors were more contributory to public hospital patients than to those in private hospitals on the basis of higher estimated value of range (R = 0.134) but a higher proportion of C-section occurred in private (93.4 %) than in public hospitals (30.3 %). On the other hand, PCAshowed that the contribution of selected risk factors accounts for approximately 60.0 % and 68.5 % in private and public hospitals, respectively. Furthermore, from the various graphical representation, thenumbers of private patients were more interlinked by ICA but not of the other graphical representations of PCA.Conclusion: We had expected the rate of C-section would be higher among public hospital patients than private hospital patients but the results obtained indicate the reverse. It seems that the combination of the propensity of private practice doctors to carry out C-section and the financial benefits on the part of private hospitals may be contributory factors to the caesarean section rates in private health facilities.Keywords: Caesarean risk factors, Composite index, Principal component analysis (PCA), Independent component analysis (ICA).

The prenatal diagnosis of isolated fetal varix of the intra-abdominal umbilical vein is associated with favorable neonatal outcome at term: a case series

Varix of the fetal intra-abdominal umbilical vein (VFIUV) has been reported to be associated with an increased risk of adverse perinatal outcome and especially with intra-uterine fetal demise (IUFD). Induction of preterm birth, as early as 32-34 weeks gestation has been suggested to minimize this risk. We aimed to evaluate our center experience with the antenatal diagnosis of VFIUV and review the relevant literature. This is a retrospective case series of all cases (between 2004 and 2009) where the sonographic antenatal diagnosis of VFIUV was registered at any gestational age (GA). Ultrasound, maternal and newborn electronic medical records were used. Descriptive statistics were employed as appropriated and correlation coefficient (r) calculated. We identified 24 women with fetuses, with isolated VFIUV (excluding one lost-to-follow-up). GA at diagnosis was 30.5 ± 4.4 weeks; 13 (56.5 %) cases were diagnosed <32 weeks. The mean VFIUV diameter was 13 ± 2.9 (range 9-20) mm and turbulent flow was reported in 7 cases (30.4 %). GA at birth was 37 ± 2.5 weeks. The small for gestational age rate was 4 % (1/23), while no case of IUFD occurred. The group induction of labor rate was 65.2 %, while 43 % (10/23) due to the diagnosis of VFIUV alone: 17 % (4/23) preterm and 26 % (6/23) at term. The cesarean rate was 17 % (4/23) and NICU admission was required for five neonates (21.7 %). The preterm induction of birth was related to a significantly increased risk for cesarean and neonatal morbidity (p = 0.015; p = 0.029, respectively). The mode of delivery was not associated with the GA at diagnosis, size/type of flow of VFIUV (r = 0.101; r = 0.727; r = 0.671, respectively) overall (r) = 0.4. All fetuses were live-born with normal follow-up at 2-60 months. Isolated VFIUV has a favorable perinatal outcome at term, unrelated to the structural and flow characteristics of VFIUV. We show that follow-up for growth abnormalities with no preterm induction of birth is a safe maternal and neonatal approach.

754: Post-cesarean maternal complications in patients with extreme obesity

754 Post-cesarean maternal complications in patients with extreme obesity David Stamilio, Molly Stout, George Macones, Christina Scifres Washington University School of Medicine, Obstetrics and Gynecology, St. Louis, MO, University of Pittsburgh School of Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, Pittsburgh, PA OBJECTIVE: Obesity is epidemic, representing a substantial disease burden. Although obesity is known to increase pregnancy complications, maternal post-operative risks among obese patients that require cesarean delivery are not well characterized. STUDY DESIGN: We performed a secondary analysis of a randomized controlled trial to estimate the effect of obesity on post-cesarean complications. The parent study was designed to estimate the effect of supplemental oxygen on post-cesarean infectious morbidity. Since study intervention had no effect, study groups were combined as a cohort. Exposure is obesity, stratified as normal/overweight (BMI 30 kg/m2), obese (BMI 30-45 kg/m2) or extremely obese (BMI 45 kg/m2). The primary outcome is a composite of wound infection and endometritis. Secondary outcomes include the composite components and wound opening, hematoma or seroma, and emergency department visit. We performed unadjusted and multinomial logistic regression analyses. Adjusted relative risk ratios (RRR) and 95% confidence intervals (CI) are reported. RESULTS: 585 women were included in the analysis. Infectious morbidity occurred in 10.4% of all patients. Rates of normal/overweight and obesity class I, II, and III were 25.1%, 30.1%, 14.9% and 29.9% respectively. Eighty-five patients (14.5%) had a BMI 45 kg/m2. Rates of black race, chronic hypertension, diabetes and gestational diabetes increased and operative duration increased with increasing obesity severity. Obese patients were more likely to undergo cesarean after labor and require a vertical skin incision or classical uterine incision. After controlling for relevant confounders, extremely obese patients had a 2-4 fold increase in postoperative complications. CONCLUSION: Maternal obesity is associated with a significant increase in post-cesarean wound complications. Risk is concentrated among class III obesity patients with BMI 45 kg/m2. These data can be used to counsel obese patients on operative risks and to target methods to reduce the risk of cesarean in extremely obese patients. 755 Impact of maternal obesity on perinatal infectious morbidity Michael Fassett, Deborah Wing, Darios Getahun Kaiser Permanente West Los Angeles Medical Center, Obstetrics and Gynecology, Los Angeles, CA, University of California Irvine, Obstetrics and Gynecology, Irvine, CA, Kaiser Permanente Southern California, Research and Evaluation, Pasadena, CA OBJECTIVE: Maternal obesity is an increasing public health problem. Studies have suggested that obesity increases placental inflammation. The aim of this study was to examine whether obesity is associated with increased risk of perinatal infectious morbidity. STUDY DESIGN: We conducted a retrospective cohort study using the 2006-2010 Kaiser Permanente Southern California medical record (n 154,275). ICD-9-CM codes from the maternally-linked hospitalizations and birth certificate data were used to examine the associations. Prepregnancy Body Mass Index (BMI, kg/m2) was defined as normal-weight (18.5-24.9), overweight (25-29.9), and obese ( 30).Odds ratio (OR) and 95% confidence interval (CI) were used to estimate the magnitude of associations after adjusting for potential confounders. RESULTS: Of the women in the study, 29 percent were overweight and 27 percent were obese. When compared to women of normal weight, overweight and obese women had a 1.31 -fold (95% CI 1.14, 1.51) and 2.11-fold (95% CI 1.86, 2.40) increased risk of surgical site infection and a 1.11-fold (95% CI 1.06, 1.16) and 1.28-fold (95% CI 1.22, 1.34) increased risk of urinary tract infection, respectively. Obesity was associated with increased risk of endometritis (OR 1.18, 95% CI 1.00, 1.41), GBS infection (OR 1.21, 95% CI 1.15, 1.27) and acute cystitis (OR 1.17, 95% CI 1.02, 1.33). CONCLUSION: The findings suggest that obese women are at increased risk for perinatal infectious morbidity and may benefit from interventions targeted at reducing infectious morbidity.

721: Impact of gestational weight gain by BMI class on cesarean delivery in nulliparous women

Nancy West, Anne Lynch, Jan Hart, Anusha Streubel, Robert McDuffie University of Colorado, Epidemiology, Aurora, CO, University of Colorado, Obstetrics and Gynecology, Aurora, CO, University of Colorado, Pediatrics, Aurora, CO, Kaiser Permanente Colorado, Obstetrics and Gynecology, Denver, CO OBJECTIVE: To construct updated birthweight reference standards using a large, contemporary, and race/ethnically diverse sample in Colorado in order to: 1) provide clinicians with an updated tool for fetal growth assessment and 2) provide updated norms for determination of smalland large for gestational age (SGA and LGA). STUDY DESIGN: In this cross-sectional study, weight-for-gestational age curves for neonates were constructed from birthweight measurements of 57,826 singleton infants (48.6% female). Neonates were born between 20 and 42 weeks gestation during 1999-2010 in the Denver metropolitan area. Gestational age was based on the best obstetrical estimate, which included ultrasound examination in the majority of cases. Sex-specific and combined-sex growth charts were constructed using the 10th, 25th, 50th, 75th, and 90th percentiles. A locally-weighted regression procedure was applied to the empirical weight-forgestational age percentiles. To investigate trends in intrauterine growth, we compared our data to the Lubchenco growth data (Lubchenco, Pediatrics, 1963), which were derived from birthweights of infants born during 1948-1961 in Denver, CO. RESULTS: The updated curves are presented in the figure. On average, male neonates weighed 3284 grams and females weighed 3181 grams. For gestational ages 24-28 weeks, contemporary neonates weighed 182 grams less than the historical neonatal population. Birthweights for gestational ages 29 and 30 weeks were similar between the two populations. For gestational ages 31-42 weeks, contemporary neonates weighed 282 grams more than the historical population. CONCLUSION: We demonstrate changes in birthweights during the past 5 decades in Colorado, including a lower mean weight at early gestational ages and a higher mean weight at later gestational ages. Use of historical growth standards will likely increase misclassification of SGA and LGA in contemporary neonates. These updated norms for intrauterine growth can facilitate monitoring of fetal growth. 721 Impact of gestational weight gain by BMI class on cesarean delivery in nulliparous women Nicole Marshall, Donna Halloran, Judith Chung, Jonathan Snowden, Yvonne Cheng, Kathryn Melsap, Elliot Main, William Gilbert, Aaron Caughey Oregon Health & Science University, Obstetrics and Gynecology, Portland, OR, St. Louis University, Pediatrics, St. Louis, MO, California Maternal Quality Care Collaborative, California Maternal Data Center, Stanford, CA, University of California, San Francisco, Obstetrics and Gynecology, San Francisco, CA OBJECTIVE: The cesarean rate in the United States continues to rise, as does maternal pre-pregnancy weight. While it is clear that obese women have higher rates of cesarean, the impact of gestational weight gain on cesarean rates by body mass index (BMI) group is unclear. The objective of this study was to determine the impact of various amounts of weight gain during pregnancy on cesarean rates by BMI category. STUDY DESIGN: This is a retrospective cohort study of birth records linked to hospital discharge data for all live born singleton infants 37-41 weeks gestation born to nulliparous California residents in 2007. Maternal BMI was determined from self-reported maternal height and prepregnancy weight. The World Health Organization BMI categories were followed including underweight, normal, overweight, and obese. RESULTS: There were 171,382 births meeting study criteria. While increasing maternal BMI was significantly associated with cesarean delivery, rising gestational weight gain increased the rate of cesarean delivery within each BMI group. Normal weight women who gained over 60 lbs and overweight women who gained 40-59 lbs faced a similar rate of cesarean as obese women who gained less than 20 lbs during pregnancy ( 35-40% in all 3 groups). Obese women who gained over 60 lbs had the highest risk of cesarean at 52.5%. CONCLUSION: Gestational weight gain is significantly associated with increased rate of cesarean in nulliparous women of all BMI categories, although the rate remains strongly associated with prepregnancy BMI. By moderating weight gain, women may be able to decrease their rate of cesarean. Figure Figure www.AJOG.org Clinical Ob, Epidemiology, ID, Intrapartum Fetal, Operative Ob, Med-Surg-Diseases, Ob Quality & Safety, Public & Global Health Poster Session V

333: Admission pulse pressure is a novel predictor of fetal heart rate abnormalities following initial dosing of a labor epidural: a retrospective cohort study

have an Apgar of 7 at 5min (p 0.5), a cord pH of 7.1 (p 0.5) or require admission to the neonatal unit (p 0.47) regardless of onset of labor. CONCLUSION: This study represents robust and reliable data relating to IOL in multiparous twin pregnancies. Women who were induced were more likely to be older, and deliver larger infants. IOL did not carry an increased risk of Cesarean or instrumental delivery. There was also no evidence of increased maternal or neonatal morbidity associated with IOL.

Gestational weight gain and adverse pregnancy outcomes in a nulliparous cohort

Excessive gestational weight gain (GWG) is an important contributing factor to the obesity epidemic in women and is associated with pregnancy complications. We investigated the relationship between GWG and caesarean delivery in labour, large for gestational age (LGA), small for gestational age (SGA) infants and pregnancy-induced hypertension by maternal pre-pregnancy body mass index (BMI) in a contemporary nulliparous cohort. Using 2009 Institute of Medicine guidelines, participants in the SCOPE study (from Cork, Ireland, Auckland, New Zealand and Adelaide, Australia) were classified into GWG categories (low, normal and high) according to pre-pregnancy BMI. Maternal characteristics and pregnancy outcomes were compared between weight gain categories. SGA and LGA were defined as <10th and >90th customised birthweight centile. Multivariable analysis adjusted for confounding factors that impact on GWG including BMI. Of 1950 participants, 17.2% (n=335) achieved the recommended GWG, 8.6% (n=167) had low and 74.3% (n=1448) had high GWG. Women with high GWG had increased rates of LGA infants [adjusted OR 4.45 (95% CI 2.49-7.99)] and caesarean delivery in labour [aOR 1.46 (1.03-2.07)]. SGA was increased in women with low GWG [aOR 1.79 (1.06-3.00)]. Three quarters of participants had high GWG, which was associated with an independent risk of LGA infants and caesarean in labour. Low GWG was associated with SGA infants. These adverse outcomes are potentially modifiable by achievement of normal GWG, which should be an important focus of antenatal care.

Indications for First Caesarean and Delivery Mode in Subsequent Trial of Labour

A previous caesarean delivery is no longer an indication per se for a subsequent, planned caesarean. We performed this study to identify women suitable for trial of labour after caesarean (TOLAC), investigating the association between the indication for the first caesarean and the risk of unplanned caesarean in the second pregnancy. We identified women with their first two pregnancies registered in the Swedish Medical Birth Registry 1992-2007. The indications for caesarean in the first pregnancy were determined using a previously published hierarchical system. For each indication group, the rate of caesarean among women with a first caesarean (n = 59 643) and a TOLAC in the second pregnancy was compared with that of primiparae (parity 0) (n = 354 053). The TOLAC rate was 69.5%. Among women with TOLAC, the uterine rupture rate was 1.1%. The success rate of TOLAC varied substantially based on the indication for the first caesarean (range 51-83%). Multiple births, breech presentation, and placenta praevia in the first pregnancy were associated with marginally increased odds of unplanned caesarean in the second pregnancy when compared with primiparae (adjusted OR 1.27 [95% CI 1.10, 1.48], 1.42 [1.34, 1.51], and 1.65 [1.17, 2.31]; OR, odds ratio; CI, confidence interval). The indications based on complications during labour/delivery, macrosomia, and maternal diabetes, were associated with substantially increased OR: 3.87 [3.70, 4.06], 4.15 [3.74, 4.61], and 4.62 [3.79, 5.63], respectively. Considering the indications for caesarean in the first pregnancy before recommending a TOLAC or a planned caesarean in the second pregnancy may help to lower the rate of unplanned caesarean deliveries.