The Consortium on Safe Labor L ATE PRETERM BIRTH (34 0 ⁄7 TO 36 6 ⁄7 weeks' gestation) accounts for 9.1% of all deliveries and three-quarters of all preterm births 1 in the United States and has been the focus of multiple investigations as well as a workshop in 2005. 2 Considerable evidence and expert opinion suggest that short-term morbidities are prevalent [2][3][4][5] and that the neonatal mortality rate is higher compared with those born at term. 6 However, much of the supporting data for these conclusions are derived from studies that are more than a decade old, are from outside the United States, or used administrative data such as birth certificate or International Classification of Diseases, Ninth Revision code data, and many were drawn from small populations. For example, Wang et al 3 studied neonates born at 35 to 36 6 ⁄7 weeks and found that a statistically higher proportion had respiratory distress syndrome (RDS) and clinical problems compared with term neonates. However, this case-control study included only 120 late preterm birth neonates. Rubaltelli et al 4 documented a 30.8% incidence of respiratory problems in neonates born at 34 to 36 weeks compared with less than 1% at term but also noted in another survey an incidence of respiratory problems of only 3% in late preterm birth. 5 Both surveys were performed 14 to 15 years ago in Italy.Given advances in obstetric and neonatal care over the last 20 years, we hypothesized that many published rates of morbidity may overestimate the clinical burden attributable to late preterm birth. We were interested in whether high rates of respiratory morbidity would be verified after careful chart review, controlling for possible confounding factors in a large cohort of late preterm infants. Thus, the purpose of this Consortium on Safe Labor members and their author affiliations are listed at the end of this article.

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.

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Context-Late preterm births (LPTB, 34 0/7-36 6/7 weeks) account for a growing proportion of prematurity-associated short term morbidities, particularly respiratory, that require specialized care and prolonged neonatal hospital stays.Objective-To assess short-term respiratory morbidity in LPTB compared to term births in a contemporary cohort of deliveries in the United States.Design, Setting, and Participants-Retrospective collection of electronic data from 12 institutions (19 hospitals) across the United States on 233,844 deliveries between 2002 and 2008. Charts were abstracted for all neonates with respiratory compromise admitted to a neonatal intensive care unit (NICU) and LPTB were compared to term births in regard to resuscitation, respiratory support and respiratory diagnoses. A multivariate logistic regression analysis compared infants at each gestational week controlling for factors that influence respiratory outcomes.Corresponding Author: Judith U. Hibbard, MD, Address: University of Illinois at Chicago, 820 South Wood Street, department of Ob/ Gyn, M/C 808, Chicago, IL 60612, Phone Number: 312 996-7300, Fax Number: 312 996-4135, jhibbar@uic.edu. * The Consortium on Safe LaborAll authors contributed to the study concept and design, acquisition of data, analysis and interpretation of data, drafting of the manuscript, critical revision of the manuscript for important intellectual content, statistical analysis, administrative, technical, or material support, and study supervision.Disclosures: All authors are without potential conflicts of interest, including specific financial interests and relationships and affiliations relevant to the subject of this manuscript. Respiratory distress syndrome decreased from 10.5% (390/3700) at 34 weeks to 0.3% (140/41,764) at 38 weeks. Similarly, TTN decreased from 6.4% (n=236) to 0.4% (n=155), pneumonia from 1.5% (n=55) to 0.1% (n=62), and respiratory failure from 1.6% (n=61) Conclusions-In a contemporary cohort, late preterm birth, compared with term delivery, was associated with increased risk for respiratory distress syndrome and other respiratory morbidity. NIH Public Access