Independent Risk Factor For Cesarean Delivery Research Articles

Validation of a Cesarean Delivery Risk Calculator in Women Undergoing Induction of Labor [39P

INTRODUCTION: Prior studies of risk factors for unsuccessful inductions are largely limited to nulliparous women with favorable cervices. Our objective is to validate a recent risk model for cesarean delivery (CD) after induction with an unfavorable cervix (Levine et al., AJOG 2018;218:254). METHODS: We performed an IRB-approved retrospective chart review of deliveries between March 2011–2019. Of 2,392 inductions, we analyzed a convenience sample of 1,050, identifying 582 full-term, singleton pregnancies with unfavorable cervices (modified Bishop score ≤6; ≤2 cm dilation). Using the Labor Induction Calculator, participants were grouped by predicted CD probability (Group 1: 0–19.9%; Group 2: 20–39.9%; Group 3: 40–59.9%; Group 4: ≥60%). Grouped analysis was performed to determine whether actual CD rates within risk groups matched the expected probability. Logistic regression was performed to determine whether higher predicted CD probability was associated with increased CD rates (STATA16.0, College Station, Texas). RESULTS: The rate of actual CD was less than predicted for our population overall (actual 19.1% v. predicted 28.3%) and for each group. In higher predicted risk groups, actual CD rates were less than predicted (Group 3: actual 36.7% vs. predicted 49.3%*; Group 4: actual 41.2% vs. predicted 66.6%*; *P<.001). Logistic regression using CD probability as an independent risk factor for CD identified an Odds Ratio of 1.05 (95% CI 1.03–1.06, P<.001). CONCLUSION: Our CD rates were lower than predicted by the model in all groups, with a particularly pronounced difference among higher risk groups. Prior to adopting risk prediction calculators, validation studies should be performed in specific populations where they will be employed.

Predictors for cesarean delivery in preterm premature rupture of membranes

Objective: To determine predictors for cesarean delivery (CD) in pregnancies complicated by preterm premature rupture of membranes (PPROM) with an intention for vaginal delivery.Materials and methods: A retrospective cohort analysis of all singleton, preterm deliveries (24 + 0 to 36 + 6 weeks) following PPROM (2007–2014). Exclusion criteria included: cases intended for CD prior to delivery; short interval from PPROM to delivery (<24 hours); cervical dilatation upon admission ≥4 cm; and major fetal anatomical/chromosomal abnormalities. Potential CD predictors were evaluated by univariate followed by multivariate regression analysis.Results: Overall, 465 deliveries met inclusion criteria. Of them, 53 (11.4%) ended with CD. Women in the CD group delivered at an earlier gestational age (34 versus 35 weeks) with lower birth weights (2115 versus 2386 grams), p < .05 for both. On univariate analysis, smaller cervical dilatation upon admission and prior to delivery, longer PPROM to delivery interval and delivery indication were the only significant determinants associated CD (p < .001 for all). On multivariable regression analysis, only la rger cervical dilatation prior to delivery remained an independent factor for lower rates of CD (aOR 0.15, 95% CI 0.08–0.28, p < .001).Conclusion: Small cervical dilatation prior to delivery is an independent risk factor for CD in pregnancies complicated by PPROM.

Estimated Fetal Weight by Ultrasound

Use of prenatal ultrasonography (US) has risen concomitantly with the increase in cesarean delivery (CD) rates. Sonographic overestimation of fetal macrosomia may be associated with a lower threshold for CD for labor arrest. If obtaining the US estimated fetal weight (US-EFW) near term increases the risk of CD, this could be a modifiable risk factor. This retrospective cohort study was undertaken to determine whether women with a US-EFW within 1 month of delivery are more likely to undergo CD compared with women without a US-EFW. The women had singleton live births; their demographic and delivery data were obtained from medical records, and the date, indication, and EFW were recorded. Patients were divided into those with a US-EFW within 1 month of delivery and women with no US-EFW. Logistic regression was used to analyze whether US-EFW was an independent risk factor for CD. The mode of delivery was the outcome variable. The statistical software package SPSS version 12.0 was used for all data analyses. Subsets created were groups at low risk, those with EFWs of less than 3000 g, those with EFWs greater than 3500 g, and those with actual birth weights of greater than 4000 g. This cohort included 2329 women with term pregnancies who met the inclusion and exclusion criteria, of whom 1168 (50.2%) had a US-EFW within 1 month of delivery. Of those with a US-EFW, 540 (46%), 276 (24%), 179 (15%), and 173 women (15%) had the US within 1 week of delivery and 1 to 2 weeks, 2 to 3 weeks, and 3 weeks to 1 month before delivery, respectively. The most common indications were “postdates” (19%), uterine size less than dates (17%), uterine size greater than dates (14%), and older maternal age (16%). Women with a US-EFW within 1 month of delivery were significantly older and more likely to be white, be cared for by a physician rather than a midwife, be obese, undergo labor induction, and deliver at slightly later gestational ages. No differences in parity, previous CD, or actual birth weight were found between the 2 groups. The unadjusted CD rates showed that women with a US-EFW were 55% more likely to have a CD (15.7% vs 10.2%; P < 0.01). The timing of US within the 1-month period before delivery had little impact. The CD rates were 16% with a US within 1 month of delivery and 16%, 15.5%, and 12% for a US within 3, 2, and 1 week(s) of delivery, respectively. The main indications for CD were failure to progress and nonreassuring fetal heart tracings in both groups. Of 17 CDs performed for presumed macrosomia, all in the US-EFW group, only 3 deliveries had an EFW of greater than 5000 g. When controlling for birth weight, maternal age, race, body mass index, previous CD, parity, gestational age, induction versus spontaneous labor, and provider group, US-EFW was a statistically significant independent risk factor for CD. Women with a US-EFW within 1 month of delivery were 44% more likely to have a CD. Other independent predictors of CD were birth weight, advanced maternal age, black or Hispanic race, nulliparity, obesity, previous CD, and faculty provider group. In the entire cohort, US-EFW was associated with increased odds of CD (odds ratio [OR], 1.44; 95% confidence interval [CI], 1.1–1.9). For those with fetuses of less than 3000 g, US-EFW was not associated with an increased risk of CD (OR, 0.97; 95% CI, 0.45–2.1). With EFW greater than 3500 g, the OR was greater and statistically significant (OR, 1.8; 95% CI, 1.3–2.7) and was stronger still for the population with an actual birth weight greater than 4000 g (OR, 3.1; 95% CI, 1.2–8.3). For women with a US-EFW within 1 month of delivery, the association between the US and CD seems to be due to provider concern over larger US-EFWs because the risk of CD was not increased if the US-EFW was less than 3000 g. However, for women with a US-EFW of greater than 3500 g, an 85% increased risk of CD was apparent with US-EFW determination. The rising CD rate is a great concern, but many of the known reasons contributing to the rise are not readily modifiable. These results indicate that provider knowledge of larger US-EFW may be associated with a higher rate of CD. Limiting the use of US to determine fetal weight near term may help to reduce the CD rate in the United States.

Maternal “isolated” obesity and obstetric complications

Objective: To investigate pregnancy outcomes, particularly cesarean delivery (CD), among women with “isolated” obesity (i.e. without additional comorbidities). Study design: We conducted a retrospective population-based study between the years 1988–2010. The pregnancy outcomes of obese (prepregnancy BMI ≥30 kg/m2) and nonobese patients were compared. Patients with chronic hypertension, pregestational diabetes mellitus, other preexisting chronic morbidities, multiple gestations, age above 40 years, grand multiparity (above 5 deliveries), lack of prenatal care, and following fertility treatments were excluded from the analysis. Stratified analyses, using multiple logistic regression models, were performed to control for confounders. Results: During the study period, a total of 173,628 deliveries met the inclusion criteria; 1605 (0.9%) occurred in patients with “isolated” obesity. Higher rates of CD were found among patients with “isolated” obesity (30.7% vs. 12.3%; odds ration [OR] = 3.2; p < 0.001). When controlling for possible confounders, using a multivariable model with CD as the outcome variable, the association between “isolated” obesity and CD remained significant (adjusted OR = 2.6; p < 0.001). No significant differences were found in the risks of perinatal complications including perinatal mortality, shoulder dystocia, congenital malformations, and low 5-min Apgar score. Conclusion: “Isolated” obesity, although not a risk factor for adverse perinatal outcomes, is an independent risk factor for CD.

Estimated fetal weight by ultrasound: a modifiable risk factor for cesarean delivery?

The purpose of this study was to investigate whether knowledge of ultrasound-obtained estimated fetal weight (US-EFW) is a risk factor for cesarean delivery (CD). Retrospective cohort from a single center in 2009-2010 of singleton, term live births. CD rates were compared for women with and without US-EFW within 1 month of delivery and adjusted for potential confounders. Of the 2329 women in our cohort, 50.2% had US-EFW within 1 month of delivery. CD was significantly more common for women with US-EFW (15.7% vs 10.2%; P < .001); after we controlled for confounders, US-EFW remained an independent risk factor for CD (odds ratio, 1.44; 95% confidence interval, 1.1-1.9). The risk increased when US-EFW was >3500 g (odds ratio, 1.8; 95% confidence interval, 1.3-2.7). Knowledge of US-EFW, above and beyond the impact of fetal size itself, increases the risk of CD. Acquisition of US-EFW near term appears to be an independent and potentially modifiable risk factor for CD.

833: Should gestational weight loss be encouraged for obese women?

be encouraged for obese women? Saju Joy, Niki Istwan, Debbie Rhea, Cheryl Desch, Gary Stanziano Carolinas Medical Center, Maternal-Fetal Medicine, Charlotte, NC, Alere Health, Department of Clinical Research, Atlanta, GA OBJECTIVE: The current pregnancy weight gain recommendation of 11-20lbs for obese women, regardless of obesity class, continues to be debated. We sought to examine pregnancy outcomes in obese women according to gestational weight gain and level of obesity. STUDY DESIGN: Women with an obese pre-pregnancy body-mass index (BMI) and current singleton pregnancy enrolled in a maternity risk screening and education program at 20w were identified. Women with a pre-pregnancy diagnosis of diabetes were excluded. Data were classified according to reported pregnancy weight gain (losing weight, under-gaining, within target, and over-gaining) and by obesity class (Class 1 BMI 30-34.9, Class 2 35-39.9, Class 3 40-49.9, Class 4 50). The recommended range of 11-20lbs for pregnancies with gestational age at delivery (GAD) 37w was used to determine weight gain group. To control for GAD 0.51/w over-gaining. Pregnancy outcomes were compared by weight gain group overall and within obesity class using Pearson’s chi-square test statistics. RESULTS: Of the 27,898 women studied, 4.4% were losing weight (mean weight change: 13.1 / 12.5lbs), 10.0% were under-gaining (mean change: 5.8 / 3.4lbs), 20.4% were gaining within target (mean change: 16.2 / 3.0lbs) and 65.2% were over-gaining (mean change: 36.8 / 12.8lbs). Pregnancy outcomes (see Table) were similar for the weight loss and under-gaining groups. Excessive weight gain was associated with adverse outcomes. These results were also observed within obesity classes 1, 2, and 3. However, for women in obesity class 4 no differences were observed between weight gain groups. CONCLUSION: Compared to women gaining weight within established guidelines, weight loss during pregnancy was associated with lower rates of macrosomic and LGA infants, but higher rates of preterm delivery and SGA infants. A reduction in cesarean delivery or gestational HTN/preeclampsia was not observed for women under-gaining or with weight loss. These data do not support recommending weight gain below current guidelines, although excessive weight gain should be discouraged for obese gravidas. 834 “Isolated” obesity: still an independent risk factor for cesarean delivery Shimrit Yaniv Salem, Ruslan Sergienko, Gershon Holcberg, Eyal Sheiner Soroka University Medical Center, Ben-Gurion University of the Negev, Department of Obstetrics and Gynecology, Faculty of Health Sciences, Beer-Sheva, Israel, Ben Gurion University of the Negev, Faculty of Health Sciences, Ben-Gurion University of the Negev Epidemiology and Health Services Evaluation Department, Beer Sheva, Israel, Soroka University Medical Center, Ben-Gurion University of the Negev, Department of Obstetrics and Gynecology, Beer-Sheva, IL, Israel, Soroka University Medical Center, Ben-Gurion University of the Negev, Department of Obstetrics and Gynecology, Beer-Sheva, Israel OBJECTIVE: To investigate pregnancy outcome among women with “isolated” obesity (i.e. without additional co-morbidities) and specifically the correlation between “isolated” obesity and cesarean delivery (CD). STUDY DESIGN: A population-based study was performed comparing all pregnancies of obese (maternal pre-pregnancy body mass index [BMI] of 30 kg/m2 or more) and non-obese patients, between the years 1988 and 2010. Patients with chronic hypertension, pre-gestational diabetes mellitus, other preexisting chronic morbidities, multiple gestations, patients older than 40 years old, grand-multiparity (above 5 deliveries), patients lacking prenatal care, and patients following fertility treatments were excluded from the analysis. Stratified analyses, using multiple logistic regression models were performed to control for confounders RESULTS: During the study period there were 173,628 deliveries meeting the inclusion criteria, of which 1605 (0.9%) occurred in patients with “isolated” obesity. Conditions significantly associated with maternal “isolated” obesity, using a multivariable model are presented in the table. Higher rates of CD were found among patients with “isolated” obesity (30.7% vs. 12.3%; OR 3.2; 95% CI 2.8, 3.5; P 0.001). When controlling for possible confounders, using another multivariable model with CD as the outcome variable, the association between “isolated” obesity and CD remained significant (adjusted OR 2.6; 95% CI 2.3-3.0, P 0.001). No significant differences were noted between the groups regarding perinatal complications such as perinatal mortality, congenital malformations, shoulder dystocia and low Apgar scores at 5 minutes. CONCLUSION: “Isolated” obesity, although not a risk factor for adverse perinatal outcomes is an independent risk factor for CD www.AJOG.org Academic Issues, Antepartum Fetal Assessment, Genetics, Hypertension, Medical-Surgical-Disease Poster Session V

Mode of delivery and other pregnancy outcomes of patients with documented scoliosis

The aim of this study was to explore whether scoliosis is a risk factor for adverse obstetric outcomes and specifically for cesarean delivery (CD) and labor dystocia. Association between scoliosis and pregnancy outcome was studied before. Confounding conclusions prevent proper counseling of patients. Appropriate statistical analysis of a suitable cohort is helpful in resolving this issue. A retrospective population-based study comparing all singleton pregnancies of women with and without documented scoliosis was conducted. Deliveries occurred between the years 1988 and 2009. Multiple logistic regression models were used to control for confounders. Out of 229,116 patients which were included in our cohort, 0.043% (n = 98) had a documented scoliosis. These patients had higher rates of fertility treatments (7.1% vs. 1.6%; p < 0.001). Scoliosis was found to be significantly associated with labor induction (36.7% vs. 26.3 %; p = 0.02) and cesarean deliveries (21.4% vs. 13.1%; p = 0.014). Using multiple logistic regression models, with CD as the outcome variable, controlling for confounders such as nulliparity, labor induction and maternal age, scoliosis was not found to be an independent risk factor for CD (OR = 1.56, 95% CI 1.9–2.7; p = 0.121). Scoliosis is not a risk factor for adverse pregnancy outcome, and specifically for labor dystocia.

Symphysiolysis as an independent risk factor for cesarean delivery

Objectives. To investigate whether symphysiolysis during pregnancy is a risk factor for cesarean delivery (CD).Methods. A retrospective population-based study comparing all singleton pregnancies of women with and without symphysiolysis was conducted. Deliveries occurred between the years 2000 and 2007. Multiple logistic regression models were used to control for confounders.Results. Out of 80,898 patients, 0.2% (n = 154) were diagnosed with symphysiolysis during pregnancy. Patients with symphysiolysis were significantly older as compared to the comparison group. These patients had higher rates of mild pre-eclampsia, gestational diabetes mellitus (GDM) and labor induction as compared to patients without symphysiolysis. Higher rates of CD were noted in pregnancies complicated by symphysiolysis [22.1% vs. 15.9%; Odds ratio (OR) = 1.5, 95% confidence interval (CI) 1.02–2.2; P = 0.036]. Using multiple logistic regression model, with symphysiolysis as the outcome variable, controlling for labor induction, mild pre-eclampsia and GDM, symphysiolysis was noted as an independent risk factor for CD (weighted OR = 1.7, 95% CI 1.1–2.5; P = 0.009). Perinatal outcomes such as low Apgar scores (<7) at 1 and 5 min and perinatal mortality were comparable between the groups.Conclusions. Symphysiolysis is an independent risk factor for CD.

Pregnancy Outcome Among Obese Women: A Prospective Study

We investigated pregnancy outcome among obese women using a prospective cohort study comparing consecutive deliveries of obese and nonobese patients. Stratified analysis, using the Mantel-Haenszel technique, was done to assess the association between obesity and the risk for cesarean delivery (CD) while controlling for confounding variables. Complete data were abstracted for 376 women, of whom 21% ( N = 79) were obese. CD rate was significantly higher among obese women (32.9% versus 18.9%; P = 0.006). Maternal obesity was associated with multiparity (odds ratio [OR] 2.97, 95% confidence interval [CI] 1.27 to 6.97; P = 0.012), fertility treatments (OR 11.3, 95% CI 2.84 to 44.89; P = 0.001), insulin-treated gestational diabetes (OR 24.55, 95% CI 2.28 to 264.08; P = 0.008), and hydramnios (OR 20.46, 95% CI 2.17 to 192.89; P = 0.008). When controlling for possible confounders, the association between maternal obesity and CD remained significant (weighted OR 2.2, 95% CI 1.2 to 4.1; P = 0.018). No significant differences were noted between the groups regarding neonatal complications. Both first and second stages of labor were longer in obese women. Obesity is a risk factor for developing gestational hypertension, insulin-treated gestational diabetes, and hydramnios. Moreover, maternal obesity is an independent risk factor for CD. Additional independent risk factors for CD were fertility treatments, insulin-treated gestational diabetes, and hydramnios. However, neonatal outcome of obese women is comparable to women with normal prepregnancy body mass index.

Familial Mediterranean fever during pregnancy: An independent risk factor for preterm delivery

Objective To investigate pregnancy outcome of patients with Familial Mediterranean fever (FMF). Study design A population-based study comparing all pregnancies of women with and without FMF between the years 1988 and 2006 was conducted. Stratified analyses, using the Mantel–Haenszel procedure and multiple logistic regression models, were performed to control for confounders. Results During the study period there were 175,572 deliveries, of which 239 occurred in patients with FMF. Using a multivariable analysis, the following conditions were significantly associated with FMF: preterm delivery (PTD, <37 weeks) (odds ratio (OR) = 1.5; 95% confidence interval (CI) 1.1–2.2), fertility treatments (OR = 2.5; 95% CI 1.4–4.4), recurrent abortions (OR = 2.2; 95% CI 1.5–3.2), labor induction (OR = 1.9; 95% CI 1.5–2.5) and malpresentations (OR = 1.8; 95% CI 1.2–2.8). Patients with FMF were more likely to deliver by cesarean delivery (CD) as compared to the comparison group (18.0% vs. 12.8%; P = 0.017). However, while controlling for possible confounders such as malpresentations, labor dystocia and failed induction, using multivariable analysis with CD as the outcome variable, FMF was not found as an independent risk factor for CD (adjusted OR = 1.2; 95% CI 0.8–1.8, P = 0.388). No significant differences were noted between the groups regarding perinatal outcomes such as low Apgar scores (<7) at 1 and 5 min (2.4% vs. 4.3%, P = 0.153 and 0.4% vs. 0.6%, P = 0.692; respectively), congenital malformations (5.2% vs. 4.9%, P = 0.838), or perinatal mortality (0.8% vs. 1.4%, P = 0.445). Stratified analysis, using the Mantel–Haenszel technique, was used to assess the association between FMF and PTD while controlling for possible confounders such as iatrogenic labor induction, fertility treatments, recurrent abortions and placental abruption. None of those variables explained the higher incidence of PTD in the group of patients with FMF. Conclusion Familial Mediterranean fever is an independent risk factor for preterm delivery. Nevertheless, perinatal outcome is comparable to the general population.