741 Estimating risk factors for developmentof preeclampsia in gravid teensArthur Baker1, Sina Haeri2

1Memorial Health University Medical Center, Obstetrics andGynecology, Savannah, GA, 2Baylor College of Medicine,Obstetrics and Gynecology, Houston, TXOBJECTIVE: Some population-based studies have implicated youngmaternal age as an independent risk factor for preeclampsia; however,data are lacking with respect to the specific maternal characteristicsrendering this group as high risk. Our objective was to estimate riskfactors for development of preeclampsia in pregnant teens.STUDY DESIGN: In a cohort study of all nulliparous teen (�18 yearsold) deliveries over a 4-year period at one institution, we identified allcases of preeclampsia using the National Working Group for Hyper-tension in Pregnancy diagnostic criteria. Group comparisons andanalysis was performed using Fishers exact, Student’s t-test, and lo-gistic regression modeling.RESULTS: Of the 730 included teen deliveries, 65 (9%) women devel-oped preeclampsia, and demonstrated a higher pre-pregnancy bodymass index (BMI) when compared with controls (32.9 vs. 30.3 kg/m2,p�0.002). Maternal obesity (BMI � 30 kg/m2, RR: 1.6, 95% CI: 1.0-2.8) and gestational weight gain above the Institute of Medicine(IOM) recommended levels (RR: 2.6, 95% CI: 1.5-4.4) were associ-ated with higher risk for development of preeclampsia. When evalu-ating by severity or onset of disease, weight gain above IOM recom-mended levels appeared as the single strongest factor associated withthe development of mild (n�58) or late onset (n�54) disease (RR:2.5, 95% CI: 1.4-3.4).CONCLUSION: Maternal obesity and higher than IOM recommendedgestational weight gain place the gravid teen at increased risk for pre-eclampsia. The modifiable nature of these risk factors permit the pos-sibility of intervention and prevention. The absence of obesity’s im-pact on early onset or severe disease in our cohort further supports arole for an underlying genetic predisposition in these women.

742 Pharmacodynamics of low-dose aspirin in pregnancyAvinash Patil1, Elizabeth Thames1, Andra James1

1Duke University Medical Center, Obstetrics and Gynecology, Durham, NCOBJECTIVE: Low-dose aspirin (LDA) is prescribed to reduce the risk ofpreeclampsia. Physiologic changes during pregnancy may limit aspi-rin’s effectiveness. The objective of this study was to assess the phar-macodynamic effects of LDA on platelet function throughout preg-nancy.STUDY DESIGN: A subset of subjects enrolled in a prospective study ofhemostatic factors in pregnancy who took LDA (81 mg daily) werecompared with the subjects who did not. Indications for LDA were ahistory of preeclampsia, poor reproductive outcome, or increased riskof thrombosis. None of the subjects continued LDA postpartum. Dur-ing the study, maternal blood samples were obtained at the end of thefirst and second trimester, and at 6 weeks postpartum (baseline). Theeffects of LDA on platelet function was assessed using light transmit-tance platelet aggregometry and an automated platelet function ana-lyzer (PFA-100). Platelet aggregometry was tested with four agonists:ADP, collagen, epinephrine, and arachidonic acid (AA). The PFA-100closure time was measured using both collagen/epinephrine and col-lagen/ADP cartridges. Kruskal-Wallis and Wilcoxon nonparametrictests were used to characterize platelet function at each timepoint.RESULTS: Of the 125 subjects enrolled, 5 received LDA during preg-nancy. Median maternal age and weight were similar between the twogroups. When the aspirin and no aspirin groups were compared, all 4agonists and the collagen/epinephrine PFA test detected a differencein platelet function (Table). Among subjects in the LDA group, therewas significant variance in aggregation between pregnancy and post-partum values with collagen (�2�0.01) and AA (�2�0.01), but notADP, epinephrine, or the PFA-100 tests. Individual timepoint com-

parisons revealed that platelet function was unchanged between thefirst and second trimester.CONCLUSION: Low dose aspirin has a consistent effect on platelet func-tion throughout pregnancy. Increased dosing of aspirin is not neces-sary to maintain its pharmacodynamic effects in pregnancy.

743 Hypertensive disease in pregnancy: an examinationof ethnic differences and the Hispanic ParadoxAvis Carr1, Maria Small2, Trace Kershaw3, Haywood Brown4

1Duke University School of Medicine, Duke University Department ofObstetrics and Gynecology, Durham, NC, 2Duke University Medical Center,Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, Durham,NC, 3Yale University School of Public Health, Epidemiology and PublicHealth, New Haven, CT, 4Duke University School of Medicine,Department of Obstetrics and Gynecology, durham, NCOBJECTIVE: The Hispanic Paradox refers to the epidemiological find-ing that Hispanics in the US have better health outcomes than theaverage population despite what their aggregate socioeconomic de-terminants would predict. The aim of this study was to evaluate ob-stetric outcomes for a multiethnic population with hypertensive dis-eases.STUDY DESIGN: We performed a retrospective review of parturientswith hypertensive disease delivering at Duke University Medical Cen-ter in 2007. We analyzed maternal sociodemographic characteristicsand ethnic differences in hypertensive disease types using Chi Square.We assessed the role of race and ethnicity on maternal and neonataloutcomes through a series of logistic regression analyses.RESULTS: 3,124 women delivered during the study period, and 9 %had hypertensive diseases in pregnancy. There were significant racialand ethnic differences in presentation (Chi-square� 39.11, p�.001)with gestational hypertension more common in Whites, chronic hy-pertension in African Americans, and mild preeclampsia in Hispan-

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ics. The overall incidence of preeclampsia was lower in Hispanics.However, severe preeclampsia rates were equal across groups. His-panics were more likely to be uninsured, younger, enter prenatal carelater, and least likely to complete high school. There was no significantdifference in smoking or parity. Stratified analyses by ethnicityshowed that the relationship between severe preeclampsia and co-morbidities (IUGR, LBW, ICN admission) were least pronounced inHispanics and strongest in African American women.CONCLUSION: Despite similar rates of severe preeclampsia and adversesociodemographic characteristics, Hispanics with severe preeclamp-sia had better pregnancy outcomes than African-Americans or Whiteswith the disease.

744 First trimester free total and fetal DNA in the maternalcirculation are not associated with preeclampsiaBob Silver1

1Eunice Kennedy Shriver National Institute of Child Health and HumanDevelopment, Maternal-Fetal Medicine Units Network, Bethesda, MDOBJECTIVE: Maternal free total and fetal DNA in the second trimester(possibly indicating abnormal placentation) has been associated withpreeclampsia. We tested the hypotheses that elevated cell-free fetaland total DNA in first trimester maternal plasma were associated withsubsequent development of preeclampsia.STUDY DESIGN: Nested case-control study of nulliparous women en-rolled in a preeclampsia prediction study comparing 175 women whodid and 175 who did not develop preeclampsia. DNA was extractedfrom maternal plasma obtained between 9-13 weeks gestation thathad been frozen at �70C. Quantitative real time PCR was used toamplify genes specific for RASSF1A (methylated in the fetus; free fetalDNA) and B-actin (control; free total DNA) genes with and withoutdigestion using methylation sensitive enzymes Hinp1I and HhaI.Standard curves were generated using serial dilutions of a knownDNA standard, samples were normalized, and free DNA levels ex-pressed as pg/ml.RESULTS: Women with and without preeclampsia were similar re-garding age, gestational age at phlebotomy, education, smoking andrace. Cases had higher systolic and diastolic BP and BMI at enrollmentthan controls. Total and fetal free DNA levels were similar betweenwomen with preeclampsia and controls (total: median 3.52 vs 3.74,p�0.96; fetal: 0.00 vs 0.00, p�0.69). Compared with Caucasians (me-dian [25-75 %ile] � 2.33 [0.03-13.1]), total free DNA was higher inAfrican American (6.15 [0.14-28.7], p � 0.024) and Hispanic (4.95[0.20-26.8], p � 0.037) women. Total free DNA levels also increasedwith increasing maternal BMI (p � 0.016). Even after adjustment forBMI and race, total and fetal free DNA levels were not associated withpreeclampsia.CONCLUSION: First trimester total or free fetal DNA levels in the firsttrimester were not associated with subsequent preeclampsia. Levels oftotal free DNA in the first trimester are increased in African Americanand Hispanic compared with Caucasian women, and these levels in-crease with increasing BMI.

745 Increase in TLR protein in preeclamptic patientsdoes not correlate with a correspondingincrease in TLR gene expressionBritta Panda1, Alexander Panda2, Vikki M. Abrahams3, ErrolNorwitz4, Aleksandar K. Stanic5, Jeffrey L. Ecker5, Bo R. Rueda5

1Massachusetts General Hospital, Vincent Obstetrics & Gynecology, MaternalFetal Medicine, Boston, MA, 2Yale University, Infectious Diseases, NewHaven, CT, 3Yale University, Ob/Gyn & Reprod Sci., New Haven, CT, 4TuftsUniversity School of Medicine, Obstetrics & Gynecology, Boston, MA,5Massachusetts General Hospital, Obstetrics & Gynecology, Boston, MAOBJECTIVE: Toll-like receptors (TLRs) are central components of theinnate immune system that recognize not only microbial ligands butalso endogenous ligands such as RNA, DNA and other proteins gen-erated in the context of cell damage or death. Data from epidemiologicstudies and animal models suggest that inappropriate activation of the

immune system plays a critical role in the development of preeclamp-sia (PE). We have previously shown that maternal dendritic cells(DCs) isolated from the circulation of patients with PE express higherprotein levels of select TLRs (3, 4, and 9) and produce more pro-inflammatory cytokines (IL-1�, TNF�) compared with healthy con-trols. In this study, our objective was to investigate whether the in-crease in TLR protein levels in women with PE is due, at least in part,to increased gene expression.STUDY DESIGN: We used RT-qPCR to evaluate gene expression ofTLR-1, 2, 3, 4, 8 and 9 in primary DCs isolated from 30 patients withPE (gestational age 37-41 weeks) and 30 gestational age-matchedhealthy controls. Total RNA was harvested from purified myeloid DCand plasmacytoid DC using the RNeasy mini kit. The expression levelof each gene in each sample was determined in duplicate, and resultswere normalized to �-actin.RESULTS: Despite differences observed at the protein level, TLR geneexpression was similar in patients with PE versus normal healthy con-trols. Additionally, amongst patients with PE, gene expression of TLR3, 4 and 9 was not statistically different than gene expression of theother TLRs.CONCLUSION: While maternal DCs from PE individuals express higherlevels of select TLRs (3, 4, and 9) and produce more pro-inflammatorycytokines compared with healthy controls, our data suggests that thiseffect is not mediated at a transcriptional level. These findings provideevidence to suggest that the elevated TLR proteins observed in DCsfrom PE patients is due in part to protein stabilization. Whether or notthe stabilization of TLR protein is a direct cause and/or consequenceof increased cytokine production in DCs remains to be determined.

746 Risk factors for and clinical courseof late postpartum preeclampsiaCatherine Bigelow1, Jennifer Cohen2, Amber Warmsley2, ChloeGetrajdman2, Erin Moshier3, Julia Paris1, Joanne Stone4

1Mount Sinai School of Medicine, OBGYN, New York, NY, 2Mount SinaiSchool of Medicine, OBGYN, New York, NY, 3Mount Sinai Schoolof Medicine, Preventive Medicine, New York, NY, 4Mount SinaiSchool of Medicine, Maternal Fetal Medicine, New York, NYOBJECTIVE: Almost no studies exist on the unique entity of late post-partum preeclampsia (LPP). We sought to evaluate risk factors(RF)for development of LPP and differences in disease course and severity.STUDY DESIGN: Between 2006-10, there were 30,476 deliveries at ourinstitution. An OB database was used to identify all patients (pts) withthe diagnosis of preeclampsia(PE), n�1,165. Charts were reviewedfor data abstraction. LPP was defined as an admission for PE followingPP discharge. Four groups of pts formed the comparison groups.Group 1 consisted of all pts with intrapartum(IP) PE and readmissionfor LPP. Group 2 included pts with only IP PE while Group 3 consistedof all pts without IP PE but with readmission for LPP. Group 4 con-stituted a matched control group of pts without IP PE or LPP. RF for

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