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Volume 168 l\umber 1. Part 2

fETAL HEART RATE (fHR) PATTERNS ASSOCIATED WITH MECONIlJ4 ASPIRATION M. Morel" M.S. Mikhail'. R. Stoessel'. A. Anyaegbunanl, Albert Einstein College of Medicine. Bronx. New York. OBJECTIVE: To evaluate FHR patterns associated with the presence thick meconium and meconium aspiration. STUDY DESIGN: We studied 3321 consecutive Singleton deliveries of cephal; c presentat; on. The ; nc i dence of thi ck meean; urn was 8% (253/3321). Intrapartum FHR tracings for. the 253 pregnancies with meconium were compared to 253 matched controls with clear amni at ic f1 ui d. Pregnanci es wi th meconi urn were further stratified into two groups based on presence or absence of meconium aspiration and frequencies of abnormal fetal heart rate patterns combi ned. RESULTS: Distribution of abnormal FHR patterns in the last Ihr. of labor ;n meconium and control pregnancies are given below. FHR Patterns in Last I hr. Meconi urn No Meconi urn

Basel ine FHR (bpm) Pro longed bradycardi a % Late decelerations % Variable decelerations % Decreased var; ab; 1 i ty % 'p<0.05.

n=253 n=253 138.4 + 10.4 139.3 + 12 10.7 - 2.8' -7.9 1.6' 49.4 50.6 8.3 1.9'

When FHR tracings in pregnancies with meconium aspiration (n=15) were compared to those without aspiration. (n=238) a Significantly (p<.05) higher frequency of FHR bradycardia (53.3%) vs. 2.9%; p<.05) was observed in the aspiration group. CONCLUSION: There is an increase in abnormal FHR patterns in pregnancies with thick meconium 'compared to those with clear amniotic fluid. In the presence of thick meconium. FHR prolonged bradycardia in the last one hour of labor is significantly associated with meconium aspiration.

MECONIUM-STAINED AMNIOTIC FLUID: WHAT'S REASSURING? M Berkus*, A. Samueloff'. E. Xenakis. N. Field, O. langer. Dept. Ob7GYil,lJTHSC. San Antonio, TX. OBJECTIVES: The purpose of this study was to determine the risk of abnormal neonatal outcome associated with meconium stained amniotic fluid (MEC) in the presence of a stringently defined normal fetal heart rate (FHR) tracing. STUDY DESIGN: The last 30 minutes of FHR tracings, prior to deliv· ery, from a cohort of 1857 consecutive, singleton, term pregnan· cies without infection or fatal malformations, were blindly coded by perinatologists. Group I consisted of FHR tracings stringently defIned as normal on the basis of having: a baseline of 120 160 bpm; variability>S bpm; accelerations~IS bpm; and no decel erations, Group II consisted of all others. Using MEC as a discrimi­nator. the groups were matched for pregnancy complications and were compared for abnormal outcome: row Apgar score; low cord pH; NICU admission; intensive respiratory support; or severe complications (ie .. hypotonia, IVH, neonatar death, convulsions). RESULTS: Outcome results (%) for each Group in the presence of moderate or thick MEC vs. none or thin MEC, are presented below: MECONIUM NO MECONIUM

rroup! rroup II) Group I Gro,p 1\ n=63 n=237 (n=417 (n=1 40

S"Apgar<7 0 3.4 a 0.7 pH < 7.2 13.1 26.3 6.9 14.9 pH<7.1S 4.9 12.3 1.5 5.6 pH<7.1 3.3 4.7 0.7 2.1 NICU 7.9 12.6 2.6 3.2 Respiratory support 7.9 8.0 2.6 2.6 Severe complications a 2.1 0.7 0.4 Fetuses in Group I with MEC had a similar risk of abnormal Apgar and cord pH as those in Group II with clear fluid or thin MEC, but more than 2-fold risk for subsequent adverse outcome. This risk for Group I with MEC increased 3·fold when associated with a pH <7.20, similar to that of Group II with MEC, but when the pH> 7.20, the risk of adverse outcome for Group I with MEC was the same as an~ tracings without MEC CONCLUSION: The presence of. and/or the conditions that lead to. meconium are the preeminent risk factor for abnormal outcome in term pregnancies. regardless of the FHR pattern. Even an absolutely normal FHR tracing requires further evaluation (scalp sampling or equivalent) to be sufficiently reassuring to allow labor to continue.

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SPO Abstracts 343

VIBROACOUSTIC STIMULATION (VAS) OF THE FETUS ENTERING SECOND STAGE OF LABOR, A. Anyaegbunam. A. Ditchil<'. R. Stoesser and M.S. Mikhair. Albert Einstein College of Medicine, Bronx, New York. OBJECTIVE: To evaluate the fetal heart rate response to VAS of fetuses entering the second stage of labor as a predictor of neonatal outcome. STUDY DESIGN: Three hundred and sixteen women and 316 matched controls were studied in the second stage of labor. All study women had VAS on entering the 2nd stage of labor using 5c electronic artificial larynx (AT&T). For control patients, the artificial larynx was not activated. The study patients were stratified into 3 groups based on the quality of FHR response R" acceleration (n = 124). R" acceleration/deceleration (n=120), R, no response, (n=72). RESULTS: Subsequent FHR accelerations and acceleration/decelerations were significantly higher in the study group compared to controls (77.2% vs. 15.2%, P < .05). The mean 5-minute Apgar score and mean umbilical cord arterial pH were not significantly different in Rl, when compared to R" and R, response groups. The incidence of nuchal cord was significantly higher for the group with R, response when compared to R, and R, groups (35.5% vs. 10.0% vs. 11.1%; p<.05). CONCLUSIONS: Vibroacoustic stimulation in the second stage of labor is associated with FHR reactivity but the quality of FHR response does not predict neonatal outcome. Acceleration/deceleration type response is suggestive of the presence of nuchal cord.

A PROSPECTIVE RANDOMIZED TRIAL OF INTRAPARTUM ELECTRONIC FETAL HEART RATE MONITORING VS.INTERMITTENT AUSCULTATION. AM Yintzjleos, AJ Antsaklis,' I Varvarigos,' P Karaiskakis,'1 Gazis,' C Pappas,' I Soratzis." JT Montgomery: Univ. or CT Health Center. Farmington, CT, Alexandra Hospital and Marika lIiadi Hospital, Athens. Greece. OBJECTIVE: To determine ir continuous intrapartum electronic retal heart rate monitoring (EFM) is associated with decreased perinatal mortality and morbidity as compared to intermittent auscultation (IA). STUDY DESIGN: The study was conducted simultaneously at two University hospitals in Athens, Greece (Alexandra and Marika lIiadi Hospitals) from 10/1/90·6/30/91. All patients with a singleton tiving fetus and gestational age 2. 26 weeks were eligible for inclusion in the study, The participants were ran­domized by flipping a coin to continous EFM or IA. Both groups were followed during labor according to ACOG guidelines (Technical 8ulletin:132,1989). Fetal scalp pH and crossover from one group to the other were not employed. The adequacy of the sample size was calculated based upon a perinatal mor· tality rate of 21/1000 (during 1989). Using an alpha statistic (error) of 0.05 and a power of 80%. a minimum of 2210 patients (1105 in each group) would be required to show a decrease in the perinatal mortality by two·thirds. RESULTS: A total of 1,428 patients were included in the interim analysis (EFM = 746 and IA = 682). There were no demographic or gestational age dif­ferences between the two groups. There was a higher incidence of nonreas· suring fetal heart rate (NR·FHR) patterns in the EFM group (23.4% vs 10.7%, p=0.0001) and therefore a higher rate of surgical intervention (11.2% vs 4.8%. p=0.0001); this difference pertained to the use of forceps (5.8% vs 2.4%, p=0.002), as well as cesarean section for NR·FHR (5.3% vs 2.3%, p=0.0005). There were no differences between the two groups in regard to any neonatal morbidity outcomes. There were 2 neonatal deaths in the EFM group (0.26%), none of which could have been prevented by EFM. There were 9 perinatal deaths in the IA group (2 intrapartum and 7 neonatal deaths). Of the neonatal deaths, 4 occurred in depressed (5·minute Apgar scores <7), acidotic (cord artery pH 57.13) infants. The perinatal death rate related to in· trauterine hypoxia was significantly less in Ihe EFM group (01746 or 0% vs 6/682 or 0.9%, p=O.03). CONCLUSIONS: Continuous intrapartum EFM decreases the number of peri· natal deaths due to intrauterine hypoxia but has no effect on neonatal morbid· ity.