457 Feasibility of implementing magnesium sulfatefor neuroprotection in a tertiary obstetric unitSusan Walker1, Amber Kennedy2,Lin Li Ow1, Elizabeth McCarthy1

1Mercy Hospital for Women, University Of Melbourne Departmentof Obstetrics and Gynaecology, Melbourne, Australia, 2MercyHospital for Women, University of Melbourne Dept ofObstetrics and Gynaecology, Melbourne, AustraliaOBJECTIVE: to determine whether research recommendations regard-ing magnesium sulfate for fetal neuroprotection can be successfullytranslated into clinical practice in a tertiary obstetric center.STUDY DESIGN: The clinical practice guideline Magnesium sulfate forprevention of cerebral palsy was developed and implemented atMercy Hospital for Women in October 2009. The study populationincluded all women admitted between 23 and 32 weeks gestation inthe following 12 months to determine the number of women triagedto receive magnesium sulfate, the proportion of infants who receivedmagnesium sulfate prior to delivery and the total number of doses(necessary and unnecessary) administered over the 12 month period.RESULTS: 330 women were admitted at a mean gestational age of 28.2weeks. 132/330(40%) were prescribed Magnesium sulfate, of whom123/132(93%) delivered. 142/191(73%) infants born at less than 32weeks gestation received Magnesium sulfate prior to delivery, with nosignificant differences seen by plurality or gestational age. Of the 145doses in 12 months, only 13 women received more than one dose, andonly 9/145 (7%) doses proved to be unnecessary (delivery never even-tuated prior to 32 weeks gestation). The median treatment durationwas 3 hours 58 minutes. The infusion was discontinued due to sideeffects in only 2% of patients.CONCLUSION: Research recommendations regarding administrationof Magnesium sulfate with neuroprotective intent can be successfullytranslated into clinical practice. Appropriate triaging of women athigh risk of imminent preterm birth is feasible, enabling a high level ofMagnesium sulfate coverage for infants that deliver prior to 32 weeks’gestation, with minimal toxicity and a low rate of unnecessary mater-nal exposure.

458 Recurrent preterm birth prevention in women receivingprophylactic 17P experiencing symptoms of preterm laborAndrei Rebarber1, Ashley Roman1, Nathan Fox1, Niki Istwan2,Debbie Rhea2, Cheryl Desch2, Daniel Saltzman1

1Carnegie Imaging for Women, Obstetrics and Gynecology, New York,NY, 2Alere Health, Department of Clinical Research, Atlanta, GAOBJECTIVE: Weekly injection of 17P is a prophylactic treatment thathas been shown to reduce the risk for recurrent spontaneous pretermbirth. The purpose of the present study was to compare rates of recur-rent preterm delivery (PTD) in women that while receiving 17P hadhospital evaluation for preterm labor (PTL) symptoms and upon dis-

charge were prescribed daily telephonic assessment vs. weekly homenursing visits.STUDY DESIGN: Women with current singleton gestation and historyof spontaneous PTD (SPTD), enrolled at 16-27.9 weeks in a weekly17P home administration program were identified. The study sampleconsisted of women hospitalized for evaluation of PTL symptoms at�34 weeks, who were subsequently discharged and continued to re-ceive 17P (n�1081). Rates of recurrent SPTD, and estimated charges(for 17P program, daily assessment and nursery) were comparedoverall and by gestational age (GA) at 17P start (16-20.9 weeks or21-27.9 weeks) for those women who continued 17P with weeklyhome nurse visits only to those that were prescribed daily telephonicassessment in addition to the weekly nurse visits.RESULTS: Overall 457 of 1081 women studied (42.3%) received addi-tional daily assessment after hospitalization for PTL. Maternal char-acteristics: �1 prior PTD, smoking, single parent, and presence ofcerclage were similar between groups. Women prescribed daily assess-ment were more likely to have a cervical length �25mm (10.5% vs.6.1%, p� 0.008). Initiation of 17P after 20.9 weeks occurred in 357women (33%). Outcomes presented in table. Rates of PTD at �34 and�32 weeks and total estimated charges were significantly lower in thedaily assessment group regardless if 17P was started at 16-20.9 weeksor 21-27.9 weeks.CONCLUSION: In women receiving 17P prophylaxis, initiation of dailynursing assessment following a hospitalization for evaluation of PTLsymptoms resulted in lower rates of early PTD and was cost-effectivethrough a reduction in nursery utilization. Ongoing patient educationand frequent assessment of PTL symptoms may be beneficial in thispopulation.

459 Racial differences in self-reported and biologicmeasures of chronic stress in pregnancyAnn Borders1, Kaitlin Wolfe2, Jie Peng3, Kwang-Youn Kim3, Jane Holl2, William Grobman1

1Northwestern University Feinberg School of Medicine, Obstetrics andGynecology, Chicago, IL, 2Northwestern University Feinberg School ofMedicine, Institute for Healthcare Studies, Chicago, IL, 3NorthwesternUniversity Feinberg School of Medicine, Preventive Medicine, Chicago, ILOBJECTIVE: Chronic stress has been associated with adverse pregnancyoutcomes such as preterm birth. Elevated chronic stress in African-American women may play a role in racial disparities in preterm birth;however, racial differences in maternal stress have not been consis-tently demonstrated. The objective of this study is to identify differ-ences in self-reported and biologic measures of chronic stress betweenAfrican-American and Caucasian pregnant women.STUDY DESIGN: African-American and Caucasian pregnant womenwere recruited at an urban university hospital between May 2008 andJuly 2009. Self-reported stress was measured from 14 to 22 weeksgestation. Blood samples, collected from 14 to 22 weeks and again

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S210 American Journal of Obstetrics & Gynecology Supplement to JANUARY 2012