447 FETAL SCALP NUCLEATED RED BLOOD CELL COUNTS IN PREGNAN-CIES WITH MECONIUM STAINED AMNIOTIC FLUID ASAF FERBER1,EBRAHIM SHAHIM1, ALINA WEISSMANN-BRENNER1, MICHAEL DI-VON1, 1Lenox Hill Hospital, OB/GYN, New York, NY

OBJECTIVE: The clinical significance of meconium stained amniotic fluid(MEC) is still debated. Recent studies suggested that nucleated red blood cell(NRBC) counts are elevated in neonates with meconium aspiration syndrome.Thus, we sought to determine the correlation between intrapartum NRBCcounts, pH values and MEC.

STUDY DESIGN: Fetal scalp capillary blood specimens were prospectivelycollected in laboring patients who underwent scalp sampling. Specimens wereevaluated for pH and NRBC counts. The presence and quality of meconium inthe amniotic fluid were noted. Statistical analysis included Student’s t-test andsimple regression.

RESULTS: 78 term, singleton pregnancies formed the study population.The mean gestational age was 39.7 ± 1.2 ( ± S.D.) weeks. The mean birthweight was 3493 ± 451 grams. Themean scalp pHwas 7.26 ± 0.05 and themeanNRBC per 100 WBC was 8.8 ± 8.3. Simple regression analysis revealed nosignificant correlation between fetal scalp pH and NRBC values (P = 0.94). 17patients had MEC. Scalp pH values in patients with and without MEC were7.25 ± 0.06 and 7.26 ± 0.05, respectively, P = 0.64. However, the NRBC countsin fetuses with MEC were significantly elevated (11.4 ± 10.6 vs. 7.4 ± 6.4,respectively, P = 0.031). Patients were further divided into clear fluid/thin MECvs. moderate/thick MEC. There were no scalp pH differences between groups(7.24 ± 0.07 vs. 7.26 ± 0.05, respectively, P = 0.27). However, the NRBC countsin the moderate/thick MEC group were significantly different (14.0 ± 13.1 vs.7.6 ± 6.2, respectively, P = 0.003).

CONCLUSION: Previous studies have established an association betweenNRBC counts and perinatal outcome. Our results indicate that fetal NRBCcounts are elevated in patients withmoderate/thick MEC. No such difference inpH values was noted. We speculate that scalp NRBC counts have the potential toeither predict neonatal meconium aspiration syndrome or identify pregnanciesthat may benefit from immediate treatment.

448 INTRAPARTUM ELECTRONIC FETAL MONITORING (EFM) AND CORDGAS ANALYSIS DO NOT IDENTIFY PRETERM FETUSES WITH FETALINFLAMMATORY RESPONSE SYNDROME (FIRS) ABIMBOLA AINA-MUMUNEY1, MAGGIE BLAKEMORE1, CYNTHIA HOLCROFT1, ERNESTGRAHAM1, 1Johns Hopkins University, Gynecology & Obstetrics, Baltimore,MD

OBJECTIVE: FIRS is associated with an increased risk of neonatalneurologic morbidity. EFM and cord gas analysis were introduced with theexpectation of identifying fetuses at risk for neurologic morbidity. We tried todetermine if these techniques could identify fetuses with FIRS.

STUDY DESIGN: From 6/99-9/02, 40 infants were born between 28 & 34weeks at our institution with histologically confirmed chorioamnionitis andfunisitis. 40 controls without inflammation were matched for gestational ageand mode of delivery. 2 hours of intrapartum fetal heart rate tracing from the

end of the 1st stage of labor for vaginal deliveries or immediately prior todelivery for cesareans were analyzed by 2 independent reviewers blinded to fetaloutcome.

RESULTS: Decelerations, when analyzed by sub-type (late, early, bradycar-dia, variables), were still not significantly different between the groups.

CONCLUSION: Fetuses with FIRS with histologically confirmedchorioamnionitis and funisitis usually have reassuring fetal heart rate tracingsand are not identifiable by EFM or cord gas. They exhibit a higher cord pH,baseline FHR, % reactivity, short term variability and accelerations that,although statistically significant, are not clinically significant. Infants atincreased risk of neurologic morbidity may not be identified by currentsurveillance techniques.

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Volume 189, Number 6Am J Obstet Gynecol

SMFM Abstracts S183

A REVIEW OF THE METHOD OF DELIVERY FOLLOWING ABNORMALFETAL BLOOD SAMPLES TOM WALSH1, MICHAEL O’LEARY1, MICHAELO’CONNELL2, DECLAN KEANE3, COLM O’HERLIHY4, 1National Mater-nity Hospital, Obstetrics & Gynaecology, Dublin 2, Ireland 2NationalMaternity Hospital, Dublin, Ireland 3National Maternity Hospital, Obstetricsand Gynaecology, Dublin 2, Ireland 4University College Dublin, Obstetricsand Gynaecology, Dublin 2, Ireland

OBJECTIVE: To determine the method of delivery and management of anabnormal fetal blood sample at the National Maternity Hospital in 2001.

STUDY DESIGN: A retrospective observational study looking atprimigravidae patients in labor who had an abnomal fetal blood sample lessthan 7.25 in labor. All patients were at term, cephalic presentation and were onoxytocin for induction or augmentation of their labor. Data collection were viapatients’ partograms and a computerized database. Parameters examinedincluded the abnormal fetal blood sample, cervical dilatation at that fetal bloodsample, repeat fetal blood sample 20 minutes post discontinuation of oxytocin,method of delivery, Apgar scores, cord PH post delivery.

RESULTS: In 2001, 3441 primigravidae delivered in the National MaternityHospital, Dublin. 49.4%had oxytocin either to induce or to augment their labor.There was total number of 1137 fetal blood samples performed on this group.126 patients (7.4%) had an abnormal fetal blood sample in the first stage oflabor, prior to full dilatation. 19.3% had an unassisted vaginal delivery, 38.7%had an instrumental delivery and 48.9% had a cesarean section. There were nocerebral dysfunction or perinatal deaths.

CONCLUSION: The judicious use of repeating a fetal blood samplefollowing discontinuation of oxytocin will lead to a substantial decrease in thecesarean rate in this group of patients.

IMPROVED INTRAPARTUM FETAL ASSESSMENT WITH ADDITION OFST-SEGMENT ANALYSIS OF FETAL HEART RATE (FHR) TRACINGS:TRIAL AMONG US CLINICIANS MICHAEL ROSS1, LAWRENCE DEVOE2,KARL ROSEN3, 1Harbor-UCLA Medical Center, Department of Obstetricsand Gynecology, Torrance, CA 2Medical College of Georgia, Department ofObstetrics and Gynecology, Agusta, GA 3Neoventa Medical, Gothenburg,Sweden

OBJECTIVE: Although FHR monitoring has not decreased the rate ofperinatal asphyxia, it has been associated with increased cesarean delivery. InEuropean (EUR) trials, the addition of fetal ECG ST segment analysis tostandard FHR interpretation improves the appropriateness of obstetric in-tervention. Our goal was to determine if US clinicians, once educated in the useof the ST, could perform FHR-based decision making similar to Europeancounterparts.

STUDY DESIGN: Experienced clinicians (n = 13) from 3US sites (Med Colof Georgia, Winthrop St Un Med Ctr, NY, Hosp St Raphael, Ct) assessed 51 FHRtracings (2 to 6 h). Among the 51 fetuses, 9 had UA pH 7.05-7.14 and 10 had UApH <7.05. Clinicians first read FHR tracings alone, after which they were trainedfor ST analysis (STAN, Neoventa Medical, Sweden). Tracings (random order)were re-read with FHR and ST-segment data. For each tracing, cliniciansdetermined the time at which intervention (ie, delivery) was required.

RESULTS: Unnecessary intervention occurred more often among USclinicians using FHR only as compared to EUR experts using FHR and ST (63 vs6%; p < 0.05). US clinicians accuracy improved (25 to 62%; p < 0.001) in non-acidotic cases with STAN, but remaining less than EUR experts (94%). Therewas similar accuracy for cases with UA pH< 7.14 among US clinicians using FHRwith and without ST (89 vs 84%; NS). Similarly, with the use of ST, US and EURexperts equally intervened for cases with pH< 7.05 (100 vs 89%, NS).

CONCLUSION: Similar to the results of EUR trials, US clinicians showedmarked improvement in the accuracy of intrapartum FHR assessment andclinical decision-making when ST data were added to standard intrapartum FHRtracings. Use of ST segment data offers the potential to reduce the rate ofunnecessary C-Sections in the US.