292 SPO Abstracts

15 FETAL HYPERTENSION AND CARDIAC HYPERTROPHY IN THE DISCORDANT TWIN SYNDROME. J.E.Tolosa. C Zoppini, A. Ludomirsky, V. Bhutani, S. R. Weil, J.C Huhta. MFM and Perinatal Cardiology Sections, Pennsylvania Hospital, Philadelphia, PA. OBJECTIVE: To describe the natural history of the discordant twin syndrome by fetal echocardiography. STUDY DESIGN: 11 pairs of discordant twins: >20% weight discordance (10/11), polyhydramnios in the large/oligohydramnios in the small (9/11), monochorionic/diamniotic (10/11), between 25-34 weeks gestation at birth (mean=28wks), were followed with serial 20, M-Mode and Doppler echocardiography measurements of CIT area ratio, left ventricular wall thickness (LVW), inferior vena cava Doppler (IVC) and umbilical vein Doppler; if present, using color and continuous wave Doppler the tricuspid regurgitation (TR) peak velocity was obtained and converted to a peak fetal ventricular pressure (VP), using the modified Bernoulli equation 4x(velocity)2. RESULTS: A consistent sequence of signs in the large twin were identified: heart size enlargement: crr area ratio>.33 (54%), myocardial hypertrophy: LVW >2S.D. (100%), reverse flow in the IVC (73%), TR peak velocity, 3.8-4.7 mis, equivalent to a VP (58-88 mm/Hg)- close to twice the normal for gestational age- (45%), and umbilical vein pulsations in (36%). Two fetuses (18%) showed hydrops. Neonatal hypertension in the large twin was present in the first 24 hrs in all cases. No consistent cardiovascular changes were observed in the small twin and all were normotensive at birth. Myocardial hypertrophy was always associated with neonatal hypertension and once present in utero was sequentially accompanied by tricuspid regurgitation or abnormal venous doppler signals. CONCLUSIONS: The natural history of the discordant twin syndrome has been characterized by simple fetal echocardiographic parameters. Fetal hypertension can be diagnosed by Doppler if TR is present. Myocardial hypertrophy in the large twin is associated with severe neonatal hypertension.

16 EVALUATION OF SUBTROPHOBLASTIC BLOOD FLOW (STBF) IN NORMOTENSIVE (NT) AND HYPERTENSIVE (HTN) WOMEN. T Harstad R. Kuhlmann, M. Meye?:' D. Cruikshank. Dept. Ob/Gyn, Medical College of Wisconsin, Milwaukee, WI. OBJECTIVE: STBF in NT women during weeks 5-9 of gestation has previously been characterized as high diastolic flow and low resistance. We studied STBF during weeks 8-12 of pregnancy. STUDY DESIGN: Thirteen NT, non·smoking women with uncomplicated pregnancies were studied by Doppler assessment of STBF by determining systolicldiastolic ratios (SID) and resistance index (RI) (mean of 2·4 measurments) with the aid of color Doppler. Seven had serial measurements while 6 had single measurements. Two other women with nontreated chronic HTN (diastolic BP '" 90 mm Hg) were studied serially. RESUL TS: STBF SID and RI decreased significantly during weeks 8-12 in NT women (p< .005 for SID and RI, 8 vs. 12 weeks) (t-test). Those with HTN did not demonstrate decreases in SID or RI. CONCLUSION: The diastolic component of STBF as measured by SID appears to increase progressively in normal pregnancies as a result of decreased resistance. These changes do not occur in women with HTN.

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II I.SSt.06 .460± .015 10 1.70"'.011 416±.069 11 1.76±.04 .42.7±.OI4 12 1.50±.05 .331 t.023

9 10 11 12 13 WEEKS GESTATION

January 1993 Am J Obstet Gynecol

17 ABSENT UMBILICAL ARTERY END DIASTOLIC VELOCITY: EFFECTS ON LONGTERM INFANT GROWTH AND DEVELOPMENT. EN KellyX, G Ryan, S InwoodX, D Farine, RJ Morro~, JWK Ritchie. Perinatal Unit, Mount Sinai Hospital, University of Toronto, Ontario, Canada.

OBJECTIVE: To evaluate the longterm growth and development of infants who were, identified with absent umbilical end diastolic velocity (AEDV) in utero. STUDY DESIGN: A prospective descriptive study of 62 infants enrolled in our neonatal follow-up programme. These were survivors from a total of 82 fetuses with AEDV. Two infants with Trisomy 21 were excluded and 4 others were lost to follow-up. Thus the study group comprises 56 infants, of whom all but two were followed to a minimum of 18 months. Mean gestation at delivery, birth weight and age at latest assessment were: 32.6 wks (SD 3.3), 1305 gm (SD 665) and 20.4 months (SD 6.5). RESULTS: Mean growth percentiles (+95%CI) were HC = 43.75 (36-51), Length = 42.5 (33-52), Wt = 24.8 (18-32). Five babies were microcephalic «3%),7 were of short stature «3%) and 14 had weights <3%ile. Neurologically, 4 were globally delayed, of whom one had CPo One cognitivelyintact child also had CPo None were deaf or blind. The mean Corrected Mental Developmental Index (CMDI) was 103 (95% CI=98-108). Eighty five percent (85%) were neurologically and cognitively normal. CONCLUSION: In most cases of AEDV, the longterm outcome in surviving children is normal.

18 VILLOUS ARTERY FLOW VELOCITY WAVEFORMS AND COLOR DOPPLER FLOW PATIERNS IN PLACENTAS OF GROWTH· RETARDED FETUSES. S. Rotmensch, M. Liberati! J.S. Luo.' Y. Gollin.', J.C. Hobbins, J. A. Capel. Dept. OB/GYN, Yale Univ., New Haven, CT. OBJECTIVE: To examine intraplacental color Doppler flow (JCDF) patterns and spectral Doppler flow velocity waveforms (FVW) of villous arteries in pregnancies with intrauterine growth retardation (JUGR). STUDY DESIGN: 138 uncomplicated and 22 IUGR pregnancies between 26 and 41 weeks gestation were examined in this cross­sectional study. lCDF findings and pulsatility indices (PI) of umbilical and villous arteries were correlated with the presence of lUGR, fetal distress and Apgar scores. Villous arteries were identified by their ICDF image and FVWs were obtained by superimposition of pulse-wave Doppler. RESULTS: 1. ICDF signals from 2 or more villous arteries were detected in 811138 normal pregnancies (100%), as compared to 16 of 22 IUGR fetuses (72.7%,p<0.0001). Within the IUGR group, fetal distress occurred in 2 of 16 (12.5%) cases with detectable ICDF as compared to 5 of 6 (83.3%,p<0.005) cases with undetectable ICDF. Perinatal death occurred in 0 of 16 (0%) and 1 of 6 (16.6%,p=NS), respectively. Median Apgar scores were 8 and 5 (p<0.05), respectively, at 1 minute, and 8 and 8 (p=NS), respectively, at 5 minutes. 2. Umbilical artery PI was abnormal (>95th percentile) in 9 of 22 IUGR cases (40.9%), but villous artery PI was abnormal in only in 1 of 16 cases (16,6%,p<0.04). CONCLUSIONS: 1. Failure to detect ICDF signals is associated with IUGR and fetal distress. 2. FVWs of detectable villous arteries are usually normal in lUGR, even in the presence of extremely abnormal umbilical artery FVWs.