racial differences in the frequency of echogenic intracardiac foci in second trimester fetuses

630 ANTENATAL ULTRASOUND PREDICTORS OF NEONATAL ABDOMINAL DEFECTOUTCOME GRAHAM ASHMEAD1, MARIE BLOSSOM1, JUDETTE LOUIS1, SAEID AMINI1,1MetroHealth Medical Center at CWRU School of Medicine, Maternal FetalMedicine, Cleveland, Ohio

OBJECTIVE: To determine ultrasound parameters of fetuses with abdominalwall defects related to neonatal outcome.

STUDY DESIGN: Retrospective chart review of fetuses delivered with anabdominal wall defect (gastroschisis or omphalocele) from 1990 to 2004.Adverse neonatal outcomes were death, more than one surgical procedure,neonatal hospital stay over 50 days and sepsis. Antenatal ultrasound parameterswere bowel diameter and thickness, fetal weight, other anomalies and amnioticfluid index (AFI). Prenatal ultrasound measurements (except in 3 fetuses) wereprospective. One reviewer evaluated all images.

RESULTS: Gastroschisis was diagnosed in 37 fetuses and omphalocele in 11.One fetus in each group was lost to follow up. One of 36 (2.8%) fetuses followedfor gastroschisis was found at birth to have an omphalocele and died in theneonatal period. 5/10 (50%) of the fetuses followed with omphalocele died(P = .02). 3 of the the omphalocele fetuses that died had Trisomy 18. 12 of thegastroschisis fetuses required more than one surgery, 11 had sepsis and 8 hada prolonged hospital stay. Omphalocele fetuses had lower birthweight correctedfor gestational age than gastroschisis (P = .05). 7/10 fetuses with omphaloceleand 18/37 (48%) with gastroschisis delivered by cesarean. 4/18 (22%) fetuseswith gastroschisis delivered by elective cesarean. Increased bowel dilation wasassociated with increased sepsis and length of stay. All gastroschisis fetuses witha neonatal stay less than 50 days had an antenatal bowel dilation less than 12mm. Increased bowel dilation was associated with more than one surgicalprocedure with gastroschisis (P = .026).

CONCLUSION: Accurate antenatal diagnosis of gastroschisis versus ompha-locele is predictive of outcome. Antenatal bowel dilation was the best predictorof neonatal outcome with gastroschisis. Antenatal fetal bowel thickness, fetalweight and AFI were not predictive of gastroschisis outcome. Future studies areneeded to determine if prenatal management based on antenatal ultrasoundevaluation can improve gastroschisis outcome.

631 THE USE OF MRI AND SONOGRAPHIC CERVICAL LENGTH IN THE POSTTERMPREGNANCY JULIE GAINER1, J. M. ALEXANDER1, MICHAEL ZARETSKY1,DONALD MCINTIRE1, DIANE TWICKLER2, KENNETH LEVENO1, 1University of TexasSouthwestern Medical Center, Obstetrics and Gynecology, Dallas, Texas,2University of Texas Southwestern Medical Center, Department of Radiology,Dallas, Texas

OBJECTIVE: To determine whether MRI and sonographically derived cervicallength predicts labor outcomes in postterm pregnancies scheduled for induction.

STUDY DESIGN: From July 2003 to April 2004, nulliparous women scheduledfor a postterm induction were asked to participate in a cervical imaging study.The EGA at the time of imaging was 41-42 weeks. Those who consentedunderwent a sonographic and MRI determination of cervical length usingpreviously described techniques. Cervical length was correlated with laboroutcomes including, need for induction of labor or augmenation, length oflabor, and rate of vaginal delivery compared to cesarean for dystocia.

RESULTS: 101 women were enrolled in the study and had both an MRI andsonogram. MRI data was available on all women but only 93 had interpretablesono data available for analysis. MRI and sonographically obtained cervicallengths were significantly correlated with one another, however, the correlationcoefficient was only 0.49. The range of cervical lengths was 0 to 46 mm by MRIannd 0 to 40 mm by sonogram. Both techniques were significantly associatedwith some of the labor outcomes studied. Spontaneous labor occured in 38 of101 woman. Women who had a cervical length of !1 cm by either techniquewere more likely to labor spontaneously and less likely to require induction (P!.05) . Women who underwent induction and had a cervical length of !3 cm byeither technique had a shorter admit to delivery time (P ! .05, c2 analysis). 21women required cesarean delivery for dystocia. We did not find an associationbetween cervical length and cesarean delivery for dystocia.

CONCLUSION: MRI and sonographically obtained cervical length areassociated with spontaneous labor and length of induction. Cervical lengthobtained using MRI or sonography was not associated with need for cesareanfor dystocia. Neither modality was superior to the other in predicting laboroutcomes.

SMFM Abstracts S177

632 RACIAL DIFFERENCES IN THE FREQUENCY OF ECHOGENIC INTRACARDIAC FOCI INSECOND TRIMESTER FETUSES CRYSTAL JOHNSON1, LISA HOLLIER1, JOANMASTROBATTISTA1, 1University of Texas Health Science Center at Houston,Obstetrics, Gynecology, and Repro Sci, Houston, Texas

OBJECTIVE: To determine the prevalence of echogenic intracardiac foci (EIF)in a racially diverse population in second trimester fetuses who are both at lowrisk and high risk for aneuploidy.

STUDY DESIGN: Our ultrasound (US) database was queried from May 2003to May 2004, for obstetric US examinations from 14 to 22 weeks gestation. Allexams were performed transabdominally, and only one exam per fetus wasutilized. Multiple gestations and cases without documented ethnicity wereexcluded. Maternal race was determined by the attending physician and patientself-assignment into the following categories: Caucasian, Hispanic, AfricanAmerican, and Asian (Vietnamese, Chinese, Filipino, Japanese, Eastern Indian/Pakistani). Maternal age, gravidity and parity, and the presence of EIF wereevaluated. The prevalence of EIF was compared between different racial groups.Statistical analyses included Student’s t test for continuous variables, c2 forcategorical variables, and multivariate logistic regression.

RESULTS: 4762 US exams were reviewed; 168 (3.5%) fetuses with EIFs wereidentified. Significant differences in the percentage of EIF were demonstratedbetween ethnic groups: African American-5.5%, Asian-4.0%, Caucasian-2.5%,and Hispanic-2.3% (P ! .001). The odds of EIF were increased for AfricanAmericans compared to the other ethnic groups (OR 2.3, 95% CI 1.7, 3.2). EIFwere found in 3.9% in women !35 years of age (low risk population) and in2.6% in women R35 years (high risk population) (P = .03). Median gravidity(P! .001) and parity (P = .04) differed between cases and controls. Adjustmentfor age and parity did not change the odds of EIF for African Americans.

CONCLUSION: EIF prevalence varies in different ethnic groups. A greaterproportion of EIFs were found in the African American and Asian populations.Variations in the frequency of soft US markers, such as EIF, among ethnicgroups may be important in risk counseling.

633 THE ROLE OF FETAL CARDIAC AXIS IN THE ANTENATAL DETECTION OF STRUCTURALCARDIAC ABNORMALITIES ELISA GIANFERRARI1, ELIZABETH MILEWSKI1,ALAN BOLNICK1, CAROLYN ZELOP2, ADAM BORGIDA3, JAMES EGAN1, 1University ofConnecticut, Obstetrics and Gynecology, Farmington, Connecticut, 2SaintFrancis Hospital & Medical Center, Hartford, Connecticut, 3HartfordHospital, Obstetrics and Gynecology, Hartford, Connecticut

OBJECTIVE: The four-chamber view of the fetal heart does not image outflowtracts. It detects structural cardiac abnormalities (SCA) in the inlet portion ofthe heart. The addition of an abnormal cardiac axis may increase the range ofSCA detected. We sought to determine the efficacy of fetal cardiac axis in theantenatal detection of fetal SCA.

STUDY DESIGN: We reviewed our obstetrical ultrasound database from Jan1999 to June 2004 for all singleton pregnancies between 16-24 weeks gestation. Acardiac axis measurement of 27 to 59 degrees was considered normal. SCA wereidentified by fetal echocardiogram. We excluded those cases with arrhythmias orisolated echogenic foci. Sensitivity (Sens), false positive rate (FPR), positivepredictive value (PPV), and negative predictive value (NPV) were calculated.

RESULTS: There were 7279 fetuses with cardiac axis measurements. Therewere 83 fetuses with SCA. Of these, 54/7279 (0.7%) had an abnormal cardiacaxis and 21/54 (38.9%) had SCA. The efficacy is seen in Table 1. The followingcardiac defects were associated with an abnormal cardiac axis: VSD 6/30 (20%);ASD 1/5 (20%); aortic stenosis 1/1 (100%); atrioventricular canal defect 3/4(75%); dextrocardia 6/6 (100%); hypoplastic left heart 3/3 (100%); mesocardia1/1 (100%). Coarctation of the aorta 0/1, pericardial effusion 0/3, cardiomegaly0/1, and truncus arteriosus 0/1 were not associated with an abnormal axis in ourseries.

CONCLUSION: In our large referral population an abnormal cardiac axismeasurement was associated with 25% of SCA. The PPV, which is a more usefulmeasure of clinical relevance, was 38%. There is a strong NPV (99%) associatedwith a normal axis. The majority of lesions associated with an abnormal axiswould not typically be identified on a four-chamber view.

Efficacy of cardiac axis for structural cardiac abnormalities

Cardiac axis n Sens (%) FPR (%) PPV (%) NPV (%)

Abnormal 54 25 0.5 39 99