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www.AJOG.org Academic Issues, Antepartum Fetal Assessment, Genetics, Hypertension, Medical-Surgical Complications, Ultrasound-Imaging Poster Session V

Outcomes

� Uterineanomaly(n�203)

� Uterineanomaly(n�66,753)

Unadjustedrelativerisk (95%confidenceinterval)

Adjusted oddsratio (95%confidenceinterval) p value

TB�34 weeksn�1,974)

14.4% 3.0% 4.9 (3.5-6.8) 6.0� (4.0-9.1) � 0.01

..........................................................................................................................................................................................PTB�37 weeks(n�7,694)

40.1% 11.6% 3.5 (2.9-4.1) 5.1� (3.8-6.9) � 0.01

..........................................................................................................................................................................................PPROM(n�1,520)

7.0% 2.3% 3.0 (1.8-5.0) 3.1� (1.8-5.3) � 0.01

..........................................................................................................................................................................................Breechpresentation(n�2,049)

23.6% 3.0% 7.9 (6.1-10.1) 8.6� (6.2-12.0) � 0.01

..........................................................................................................................................................................................Cesareandelivery�

(n�8,784)

36.9% 16.4% 2.3 (1.7-2.9) 2.9 (1.9-4.3) � 0.01

..........................................................................................................................................................................................� Primary cesarean section only, and excluding those performed for breech presentation.

� Adjusted for prior preterm birth, preeclampsia, and black race. � Adjusted for prior pretermbirth, preeclampsia, black race, history of maternal renal disease, chronic hypertension,gestational diabetes, and history of IUFD. � Adjusted for prior preterm birth and black race.� Adjusted for parity and black race. Adjusted for history of preterm birth, history of IUFD,chronic hypertension, preeclampsia, and gestational diabetes.

865 Obstetrical and perinatal outcomes amongomen with gestational hypertension, mildreeclampsia, and chronic hypertension

Meredith Cruz1, Weihua Gao1, Heather Kim1, Judith U Hibbard1

1University of Illinois at Chicago, Chicago, ILOBJECTIVE: To compare maternal and neonatal outcomes with gesta-ional hypertension (GHTN), mild chronic hypertension (CHTN),nd mild preeclampsia (PRE) at delivery. Our hypothesis was thatutcomes would be similar among women with GHTN and PRE, butreater in women with CHTN.

STUDY DESIGN: The Consortium on Safe Labor electronic databaserom 19 hospitals across the United States on 228,668 deliveries 2002-008 was used to extract data on gravidas using standard definitionsith GHTN, PRE, or CHTN on no medication. Maternal predictorariables included race, parity, order, admitting BMI, admitting BP,A, past medical and social history. Maternal (MAT) outcomes were

CU admission, blood loss, cesarean rate, and length of stay (LOS);eonatal (NEO) outcomes were NICU admission, LOS, RDS, andEO deaths. Univariate analysis was performed using linear and lo-

istic regression, followed by multivariate logistic regression analysiso generate adjusted OR and 95% CI and multivariate linear regres-ion with parameter estimates and SE. Predictors included in the final

ultivariate model had been selected by backward elimination tech-ique.

RESULTS: There were 4,918 GHTN, 5274 PRE, and 2,531 CHTN. AllAT outcome variables on univariate analysis were significant; NICU

dmission and RDS were significant for NEO outcomes. On multi-ariate analysis, PRE and CHTN were less likely to require ICU ad-ission (aOR 0.3[0.16-0.54], 0.2[0.10-0.39]), but both groups hadore blood loss at delivery compared to GHTN (p�0.05). PRE wereore likely to have a CS compared to GHTN (aOR 1.2 [1.13-1.38]).

RE had the longest LOS (p�0.001). PRE infants were more likely toe admitted to the NICU (aOR 1.5 [1.3-1.74]), but less likely to haven infant with RDS compared to GHTN (aOR 0.7 [0.51-0.83]).

CONCLUSIONS: While GHTN were more likely to be admitted to ICU,RE overall had more maternal morbidity. NEO outcomes were notonsistently better in any group.

G

Supplem

866 Two-step Bayesian model averaging processocuments gene-environment interactionsssociated with spontaneous preterm birth

Michael Kramer1, Ramkumar Menon1, Stephen Fortunato2

1Emory University, Atlanta, GA, 2The Perinatal Research Center of theomens Health Research and Education Foundation, Nashville, TN

OBJECTIVE: Identification of important gene-environment (GxE) in-eractions is necessary to advance prevention and treatment efforts forpontaneous preterm birth (sPTB). Complicating this search is thehallenge of identifying meaningful interactions in highly dimen-ional datasets. We report a novel method of testing GxE interactionso document risk association in sPTB.

STUDY DESIGN: Genetic data from 1442 SNPs from 130 candidategenes in sPTB pathophysiologic pathways and environmental riskvariables (smoking, BMI, socio-economic stress) in African American(AA) (n�266, cases�75) and Caucasian (C) (n�340, cases�146)mothers were used. A two-step Bayesian Model Averaging (BMA)algorithm was implemented to identify GxE interactions. BMA aver-ages parameter values across all-possible model combinations allow-ing for uncertainty in model specification. In Step 1 environmentalvariables were regressed on SNPs to identify those with the highestprobability of association. High probability SNPs were entered in Step2 BMA models as main and interacted effects with environmentalvariables. Results are summarized as the probability for each GxEcombination being significant.RESULTS: Step 1 BMA reduced potential SNPs from 1442 to 6 (smok-ng), 8 (BMI), and 11 (stress) candidates with posterior probability

10% of interacting with environmental variables. Step 2 BMA iden-ified 3 SNPs with moderately high probability of significant GxE in-eraction. A SNP in the angiotensin converting enzyme (ACE) genead 80% probability of interacting with stress increasing sPTB riskOR 1.30, 95%CI 0.98,2.36) in AA and C mothers. In AA mothers,NPs in the TLR7 and MMP2 genes had 83% and 70% probability ofnteraction with BMI and Smoking respectively.

CONCLUSIONS: This 2-step BMA allows examination of analytic com-lexities inherent in finding GxE interactions for sPTB. An interactionetween SNP in ACE gene and socio-economic stress increases theisk of sPTB regardless of race. Understanding such interactions andacial disparity will allow better modeling of sPTB risk.

867 Age at menarche, menstual caracteristicsnd the risk of gestational diabetes

Michal Dishi-Galitzky1, Daniel A Enquobahrie1, Dejene F Abetew1,iu Chun-fang1, Carole B. Rudra2, Michelle A. Williams1

1Swedish Medical Center, Seattle, WA, 2Departmentof Social and Preventive Medicine, Buffalo, NYOBJECTIVE: Early menarche and long or irregular menstrual cycles

ave been associated with higher risk of developing type 2 diabetesT2DM). Since gestational diabetes mellitus (GDM) shares severalisk factors with T2DM and women who experienced GDM are atncreased risk for developing T2DM, we examined associations of aget menarche and menstrual cycle characteristics with risk for GDM.

STUDY DESIGN: The study population (N�3,490) was selected fromarticipants of a prospective cohort study. Women attending prenatalare clinics were recruited prior to 16 weeks of gestation and followedntil delivery. GDM was diagnosed using the American Diabetes As-ociation (2002) guidelines. Information on age at menarche and

enstrual characteristics was collected using interviewer-adminis-ered questionnaires. Logistic regression was used to estimate oddsatios (OR) and 95% confidence intervals (CI). We also examinedhether pre-pregnancy obesity (body mass index �30kg/m2) and

adulthood weight gain (�5 kg) modified associations of age at men-arche and menstrual characteristics with risk of GDM.RESULTS: Among study participants, 185 (5.3%) developed GDM.

omen who had long menstrual cycles (�36 days) had higher risk of

DM compared with women who had normal cycle length (25-30

ent to JANUARY 2011 American Journal of Obstetrics & Gynecology S335