proportion of neonates born to mothers with elevated EDS had an Apgar score less than 7 at 5 minutes (27.3% vs 12.1%, p-value50.1) although this was not statistically significant. No differences were noted in maternal weight gain or birth weight discordance. CONCLUSION: There is a trend toward an increased rate of preterm delivery and lower Apgar score in multiple gestations with a positive antepartum maternal EDS score. Further studies are needed to assess if treating these high-risk patients reduces their rate of preterm delivery. Financial Disclosure: The authors did not report any potential conflicts of interest. Fetal Maternal Size Disproportion: Explanation for the Racial Disparity of OASIS? [7R] Youngwu Kim University of Massachusetts Medical School, Worcester, MA Kasey Hebert, Jessica Masiero, Katherine Leung, MPH, Tiffany A. Moore Simas, MD, MPH, Med, and Heidi Leftwich, DO INTRODUCTION: Obstetric anal sphincter injuries (OASIS) are a significant complication of vaginal deliveries. Asian race is a known independent predictor of perineal trauma. Limited data demonstrate a plausible explanation of this racial disparity. We aim to assess the relationship between the fetal maternal size disproportion as measured by fetal birth weight to prepregnancy BMI ratio (BW:BMI) and OASIS in mothers of different race groups. METHODS: Retrospective cohort study of vaginal deliveries between 2006 and 2015. Demographics and obstetrical data were abstracted and compared. The significance of BW:BMI to OASIS was evaluated. Results adjusted for confounding factors. RESULTS: 16,024 vaginal deliveries were included. 28.5% had no lacerations, 64.6% had 1st or 2nd degree lacerations, and 6.9% had OASIS. Demographic factors associated with OASIS included Asian race, nulliparity, increased age, increased birth weight, episiotomy, trial of labor after cesarean, and operative vaginal deliveries. Although BMI was not an independent risk factor, BW:BMI showed a significant relationship with OASIS. For every 10 unit increase in BW:BMI, the adjusted odds of having an OASIS increased by 16% (p5, .001). After adjusting for BW:BMI, Asian race had higher OASIS rates. Interaction between race groups and BW:BMI was only significant for 1st and 2nd degree lacerations, not OASIS. CONCLUSION: This study verified known risk factors associated with OASIS. Increasing BW:BMI is associated with OASIS. However, BW:BMI does not provide insight into OASIS racial disparities; further investigations are needed to understand why Asian race is an OASIS risk factor. Financial Disclosure: The authors did not report any potential conflicts of interest. Fetal Doppler Evaluation and Perinatal Outcomes in the Absence of Fetal Growth Restriction [8R] Niamh Condon, DO Penn State Hershey Medical Center, Harrisburg, PA Francis Martinez, DO INTRODUCTION: Antepartum fetal surveillance techniques are used to assess fetal well-being in pregnancies complicated by preexist- ing maternal conditions, and pregnancies in which complications develop (1). The application of Doppler velocimetry to antepartum fetal assessment allows for evaluation of placental status and helps to determine the relative risk of sudden fetal deterioration (2). The purpose of this study is to determine whether patients with hyperten- sion or preeclampsia and normally grown fetuses yet abnormal Doppler studies are at an increased risk for adverse perinatal outcomes. METHODS: This is a retrospective review of 287 high-risk pregnancies with appropriate-for-gestational- age (AGA) fetuses who had ultrasound evaluations between January 2012 and December 2013. Ultrasound evaluation included fetal growth assessments every four weeks with umbilical artery (UA) and middle cerebral artery (MCA) Doppler interrogation. The control group always had normal Dopplers. The study group had at least one abnormal UA Doppler or one abnormal MCA Doppler. Perinatal outcomes were compared between the groups. RESULTS: Of the 287 high-risk AGA pregnancies evaluated, 12.5% (n536) had at least one abnormal UA or MCA Doppler. Pregnancies complicated by hypertension or preeclampsia had a statistically signif- icant increased risk of having an abnormal UA and/or MCA Doppler (p50.0013 and p50.0086, respectively), and were significantly more likely to deliver preterm (p50.0066 and p50.0001, respectively). CONCLUSION: Fetoplacental circulation may be altered in preeclamp- tic and hypertensive patients, yet the fetus may not be growth restricted. Abnormal umbilical and middle cerebral artery Dopplers in AGA pregnancies may identify those fetuses that are at risk for preterm delivery. Financial Disclosure: The authors did not report any potential conflicts of interest. Maternal Outcomes of Prolonged Induction of Labor [9R] Jourdan Triebwasser, MD, MS University of Michigan, Ann Arbor, MI Jamie VanArtsdalen, MD, Emily Kobernik, MPH, CPH, and Elizabeth Langen, MD INTRODUCTION: To safely reduce the number of cesarean deliv- eries (CD), the time allowed for induction of labor (IOL) has increased. There is little data regarding the safety of prolonged labor induction. METHODS: We performed a retrospective study of IOL from July, 2014 – June, 2016. Singletons, greater than 36 weeks, with initial cer- vical dilation 4 or less were included. Bivariate analysis was performed to compare maternal outcomes by induction length. Multivariable logistic regression identified independent predictors of CD and was subsequently stratified by parity. RESULTS: We included 2,032 inductions. For IOL less than 24 hours, 24 to 36 hours, and greater than 36 hours the CD rate was 14.9%, 24.5%, and 43.4% (p , .001) for nulliparous women and 5.5%, 11.2%, and 18.7% (p , .001) for multiparous women. After risk adjust- ment, the odds of CD were significantly higher for women age 30 or greater, (aOR51.83, 95%CI 1.42-2.38), BMI 35 or greater, (aOR 1.58, 95%CI 1.21-2.06), previous CD (aOR 12.06 95%CI 6.72-21.67), dura- tion of labor 24 to 36 hours (aOR 1.74 95%CI 1.25-2.42), and duration of labor greater than 36 hours (aOR 1.74 95%CI 1.25-2.42). When stratified, age, BMI, and duration of labor for nulliparous and prior CD and duration of labor for multiparous women were significant. Chorioamnionitis also increased by duration, 5.5%, 8.9%, and 14.6% for nulliparous women (p , .001), and 1.4%, 2.0%, and 9.2% for multiparous women (p5.001). CONCLUSION: As the length of IOL increases the risk of CD and infection increases. This data can be used to better inform patients of the risks of prolonged IOL. Financial Disclosure: The authors did not report any potential conflicts of interest. Maternal Risk Factors in a Cohort Study of Mexican Americans Living Near the U.S.-Mexico Border [10R] Divya Patel, PhD University of Texas System, Office of Health Affairs and University of Texas Health Northeast, Austin, TX Meliha Salahuddin, MBBS, MPH, Rose Gowen, MD, Susan Fisher- Hoch, MD, and Joseph McCormick, MD INTRODUCTION: Preterm and early term births are higher in border versus non-border regions of Texas, though the prevalence of maternal risk factors contributing to negative birth outcomes in this region is not well understood. METHODS: Weighted descriptive analyses were conducted on self- reported medical history and information on first pregnancy collected from 384 women ages 19-49 at enrollment into the Cameron County Hispanic Cohort, a prospective study of Mexican Americans residing in South Texas near the U.S.-Mexico border. VOL. 129, NO. 5 (SUPPLEMENT), MAY 2017 TUESDAY POSTERS 185S Copyright ª by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited.