Objective-To describe contemporary cesarean delivery practice in the U.S.Study Design-Consortium on Safe Labor collected detailed labor and delivery information from 228,668 electronic medical records from 19 hospitals across the U.S., 2002 -2008. Results-The overall cesarean delivery rate was 30.5%. 31.2% of nulliparas were delivered by cesarean section. Prelabor repeat cesarean delivery due to a previous uterine scar contributed 30.9% of all cesarean sections. 28.8% of women with a uterine scar had a trial of labor and the success rate Corresponding author: Dr. Jun Zhang, Epidemiology Branch, NICHD, National Institutes of Health, Building 6100, Room 7B03, Bethesda, MD 20892, Tel: 301-435-6921, zhangj@mail.nih.gov. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public Access Author ManuscriptAm J Obstet Gynecol. Author manuscript; available in PMC 2011 October 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript was 57.1%. 43.8% women attempting vaginal delivery had induction. Half of cesarean for dystocia in induced labor were performed before 6 cm of cervical dilation.Conclusion-To decrease cesarean delivery rate in the U.S., reducing primary cesarean delivery is the key. Increasing VBAC rate is urgently needed. Cesarean section for dystocia should be avoided before the active phase is established, particularly in nulliparas and in induced labor.

Objective-To use contemporary labor data to examine the labor patterns in a large, modern obstetric population in the United States.Methods-Data were from the Consortium on Safe Labor, a multicenter retrospective study that abstracted detailed labor and delivery information from electronic medical records in 19 hospitals across the United States. A total of 62,415 parturients were selected who had a singleton term gestation, spontaneous onset of labor, vertex presentation, vaginal delivery, and a normal perinatal outcome. A repeated-measures analysis was used to construct average labor curves by parity. An interval-censored regression was used to estimate duration of labor stratified by cervical dilation at admission and centimeter by centimeter. Results-Labor may take over 6 hours to progress from 4 to 5 cm and over 3 hours to progress from 5 to 6 cm of dilation. Nulliparas and multiparas appeared to progress at a similar pace before 6 cm. However, after 6 cm labor accelerated much faster in multiparas than in nulliparas. The 95 th percentile of the 2 nd stage of labor in nulliparas with and without epidural analgesia was 3.6 and 2.8 hours, respectively. A partogram for nulliparas is proposed.Conclusion-In a large, contemporary population, the rate of cervical dilation accelerated after 6 cm and progress from 4 to 6 cm was far slower than previously described. Allowing labor to continue for a longer period before 6 cm of cervical dilation may reduce the rate of intrapartum and subsequent repeat cesarean deliveries in the United States.

Objective To use contemporary labor data to examine the labor patterns in a large, modern obstetric population in the United States. Methods Data were from the Consortium on Safe Labor, a multicenter retrospective study that abstracted detailed labor and delivery information from electronic medical records in 19 hospitals across the United States. A total of 62,415 parturients were selected who had a singleton term gestation, spontaneous onset of labor, vertex presentation, vaginal delivery, and a normal perinatal outcome. A repeated-measures analysis was used to construct average labor curves by parity. An interval-censored regression was used to estimate duration of labor stratified by cervical dilation at admission and centimeter by centimeter. Results Labor may take over 6 hours to progress from 4 to 5 cm and over 3 hours to progress from 5 to 6 cm of dilation. Nulliparas and multiparas appeared to progress at a similar pace before 6 cm. However, after 6 cm labor accelerated much faster in multiparas than in nulliparas. The 95th percentile of the 2nd stage of labor in nulliparas with and without epidural analgesia was 3.6 and 2.8 hours, respectively. A partogram for nulliparas is proposed. Conclusion In a large, contemporary population, the rate of cervical dilation accelerated after 6 cm and progress from 4 to 6 cm was far slower than previously described. Allowing labor to continue for a longer period before 6 cm of cervical dilation may reduce the rate of intrapartum and subsequent repeat cesarean deliveries in the United States.

Objective To identify whether prenatal depression is a risk factor for fetal growth restriction. Methods Midgestation (18-20 weeks GA) estimated fetal weight and urine cortisol and birth weight and gestational age at birth data were collected on a sample of 40 depressed and 40 non-depressed women. Estimated fetal weight and birthweight data were then used to compute fetal growth rates. Results Depressed women had a 13% greater incidence of premature delivery (Odds Ratio (OR) = 2.61) and 15% greater incidence of low birthweight (OR = 4.75) than non-depressed women. Depressed women also had elevated prenatal cortisol levels (p = .006) and fetuses who were smaller (p = .001) and who showed slower fetal growth rates (p = .011) and lower birthweights (p = .008). Mediation analyses further revealed that prenatal maternal cortisol levels were a potential mediator for the relationship between maternal symptoms of depression and both gestational age at birth and the rate of fetal growth. After controlling for maternal demographic variables, prenatal maternal cortisol levels were associated with 30% of the variance in gestational age at birth and 14% of the variance in the rate of fetal growth. Conclusion Prenatal depression was associated with adverse perinatal outcomes, including premature delivery and slower fetal growth rates. Prenatal maternal cortisol levels appear to play a role in mediating these outcomes.

Objective To characterize potentially modifiable risk factors for third- or fourth-degree perineal lacerations and cervical lacerations in a contemporary U.S. obstetric practice. Methods The Consortium on Safe Labor collected electronic medical records from 19 hospitals within 12 institutions (228,668 deliveries from 2002 to 2008). Information on patient characteristics, prenatal complications, labor and delivery data, and maternal and neonatal outcomes were collected. Only women with successful vaginal deliveries of cephalic singletons at 34 weeks of gestation or later were included; we excluded data from sites lacking information about lacerations at delivery and deliveries complicated by shoulder dystocia; 87,267 and 71,170 women were analyzed for third- or fourth-degree and cervical lacerations, respectively. Multivariable logistic regressions were used to adjust for other factors. Results Third- or fourth-degree lacerations occurred in 2,516 women (2,223 nulliparous [5.8%], 293 [0.6%] multiparous) and cervical lacerations occurred in 536 women (324 nulliparous [1.1%], 212 multiparous [0.5%]). Risks for third or fourth-degree lacerations included nulliparity (7.2-fold risk), being Asian or Pacific Islander, increasing birth weight, operative vaginal delivery, episiotomy, and longer second stage of labor. Increasing body mass index was associated with fewer lacerations. Risk factors for cervical lacerations included young maternal age, vacuum vaginal delivery, and oxytocin use among multiparous women, and cerclage regardless of parity. Conclusion Our large cohort of women with severe obstetric lacerations reflects contemporary obstetric practices. Nulliparity and episiotomy use are important risk factors for third- or fourth-degree lacerations. Cerclage increases the risk for cervical lacerations. Many identified risk factors may not be modifiable.

Objective-To assess body mass index (BMI) effect on cesarean risk during labor.Study Design-The Consortium on Safe Labor collected electronic data from 228,668 deliveries. Women with singletons ≥37 weeks and known BMI at labor admission were analyzed in this cohort study. Regression analysis generated relative risks for cesarean stratifying for parity and prior cesarean while controlling for covariates Results-Of the 124,389 women, 14.0% had cesareans. Cesareans increased with increasing BMI for nulliparas, multiparas with and without a prior cesarean. Repeat cesareans were performed in >50% of laboring women with a BMI >40kg/m 2 . The risk for cesarean increased as BMI increased for all subgroups, p<0.001. The risk for cesarean increased by 5%, 2%, and 5% for nulliparas, multiparas with and without a prior cesarean, respectively, for each 1kg/m 2 rise in BMI.Conclusion-Admission BMI is significantly associated with delivery route in term laboring women. Parity and prior cesarean are other important predictors.

OBJECTIVE-We sought to determine maternal and neonatal outcomes by labor onset type and gestational age.STUDY DESIGN-We used electronic medical records data from 10 US institutions in the Consortium on Safe Labor on 115,528 deliveries from 2002 through 2008. Deliveries were divided by labor onset type (spontaneous, elective induction, indicated induction, unlabored cesarean). Neonatal and maternal outcomes were calculated by labor onset type and gestational age.RESULTS-Neonatal intensive care unit admissions and sepsis improved with each week of gestational age until 39 weeks (P < .001). After adjusting for complications, elective induction of labor was associated with a lower risk of ventilator use (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.28 -0.53), sepsis (OR, 0.36; 95% CI,, and neonatal intensive care unit admissions (OR, 0.52; 95% CI, 0.48 -0.57) compared to spontaneous labor. The relative risk of hysterectomy at term was 3.21 (95% CI, 1.08 -9.54) with elective induction, 1.16 (95% CI, 0.24 -5.58) with indicated induction, and 6.57 (95% CI, 1.78 -24.30) with cesarean without labor compared to spontaneous labor.Presented orally at the 30th Annual Meeting of the Society for Maternal-Fetal Medicine, Chicago, IL, Feb. 1-6, 2010. The racing flag logo above indicates that this article was rushed to press for the benefit of the scientific community.Reprints not available from the authors. NIH Public Access Author ManuscriptAm J Obstet Gynecol. Author manuscript; available in PMC 2011 March 1. Over the last few years, evidence for poorer neonatal outcomes at <39 weeks has been published. [2][3][4][5] In light of these data, clinicians should counsel patients on the increased risks to the neonate of a scheduled delivery <39 weeks. However, with few data available, it has been difficult to counsel patients about the maternal risks of elective induction in comparison to other labor onset types.The studies on early term neonatal outcomes have been from single centers or used administrative data that lacked some clinical detail. Tita et al 4 published a nationally representative multicenter study based on abstracted medical records. That study showed neonatal outcomes were worse in babies delivered <39 weeks, but it only looked at repeat cesarean deliveries.The Consortium on Safe Labor is a National Institutes of Health multicenter collaborative study designed to characterize labor and delivery in a contemporary group of women experiencing current obstetric clinical practices. By design, study hospitals had to have obstetric electronic medical records (EMR) that coded data into prespecified fields that would allow for data to be abstracted and combined into a uniform dataset for subsequent analysis of patient-specific risk factors and maternal and neonatal outcomes. Unlike electronic administrative data, EMRs are a direct clinical source and are rich in clinical and demographic details. These data offer the advantages of a large national sample size while maintaining the clinical detail of a single...

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