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330 SPO Abstracts

THE IMPACT OF ALPHA ADRENERGIC STIMULATION ON UMBILICAL BLOOD FLOW. HENDRICKS S. BAKER E*, SLACK D* DEPARTMENT OF OB·GYN, UNIVERSITY OF WASHINGTON, SEATTLE

This study evaluates the potential effects of intranasal phenylephrine, an alpha adrenergic agonist used for respiratory congestion, on uteroplacental blood flow . This vasopressor has been shown to cause uterine artery constriction in animals. Ten subjects were recruited from the Women's Clinic. Inclusion criteria were maternal age >18 yr., singleton gestation, absence of medical illness and gestational age of 22-38 wks. 0.2 cc of phenylephrine (1 % aq) was applied to each nostril. Measurements of BP, pulse, umbilical and uterine artery velocimetry, and fetal heart rate were performed prior to drug administration and at 5, 15, 30, 45, and 60 min. after administration. Statistical analysis was performed by a repeated measures ANOYA at 95% significance. Age range was 22-37 yrs with GA range of 24-35 wks. All had normal baseline umbilical artery SID ratios. The diastolic flow velocity waveform decreased significantly at 15 min. and 30 min. compared to baseline. The findmgs at 30 min. were >2 SO from the mean in four subjects. There were no significant changes in maternal pulse, blood pressure, uterine artery velocirnetry and fetal heart rate. Two fetuses had a transient tachycardia. Conclusions: Umbilical Doppler showed velocity patterns consistent with vasoconstriction at 15 and 30 min. The use of over-the-counter alpha adrenergic agents may resull in decreased umbilical artery flow velocities, and in high risk pregnancies these medications may be contraindicated.

lL .u: lQ.: ~ UA SO 3.2±.95 4.1±2.2* 4 .7±2.2* 3.7±1.2

* Significant at 95% level compared with baseline, 5 and 60 minute intervals.

INTERRELATIONSHIP AND CLINICAL SIGNIFICANCE OF INCREASED RESISTANCE IN THE UTERINE ARTERIES IN PATIENTS WITH HYPERTENSION AND/OR PREECLAMPSIA Alexander D. Koflnas, M.D. , Mary Perry, R.N.ROMS', NIcolas V. S1111On, M.D., Melissa Swain, R. N.' Bo..",an Gray School of Medicine, Winston-Salem, NC and York Hospital, York, PA

We exami ned 123 pregnant women wi th chroni c hypertensi on and/or preeclampsia In the 3rd trimester of pregnancy. Umbi I ical artery (UA) and uterine artery (UtA) resistance was eva I uated by means of cant i nuous wave Ooppl er ultrasound . Placental location was determIned by real time ultrasound. Cllmcal outcomes were compared accordIng to UtA abnormalities. In patients with unilateral placenta (N=67) , the placental uterine artery (PUtA) .s a better predictor of poor outcome than the nonplacental artery (NPUtA) and the mean of the two arteries (MUtA). There is a moderate degree of carre I at i on between abnormal PUt A and abnormal MUtA (Pearson's r = 0.46, P < 0.001) while there is a strong carre I at i on of abnormal i ty between the NPUtA and MUtA (Pearson's r = 0.76, P < 0.0001). When the NPUtA is normal, the MUtA is normal in 96% of the patients. However, when PUtA is norma I, the MUtA is norma lin 70% and abnormal in 30% of the patients primarily because of an elevated NPUtA. With all other clInical characteristics being simIlar, the presence of uni I atera I placenta in hypertensi ve pati ents was associated WIth Increased neonatal morbidity (p < 0.05). ConclUSIons: (I) The PUt A is a better predi ctor of poor pregnancy outcome than the MUtA. (2) The NPUtA is a poor predictor of pregnancy outcome . (3) The degree of abnormality of MUtA is mostly affected by the NPUtA in patIents w.th unilateral placenta. (4) It is important to evaluate each vessel separately part.cularly in patients WIth unilateral placenta. (5) Un. lateral placenta is an addItional risk factor in patIents with hypertensIon.

.Jan liar} l YY l Am J Obstet G) newl

310 UMBILICAL VENOUS PULSATIONS ARE ASSO­CIATED WITH INFERIOR VENA CAVA FLOW VELOCITIES. Julie H. Indik,x Kathryn L. Reed, AZ Health Sciences Center, Tucson, AZ

311

Pulsations in umbilical venous Dopp­ler blood flow velocity with heart rate (VP) were examined in 21 fetuses with absent end-diastolic velocities in the umbilical artery. Reverse flow in the inferior vena cava (IVC) with atrial contraction was quantitated as a per­cent of forward flow (AK/FF).

VP+ VP-

n IVC AK/FF(%) Mortality(%) 11 27.5±14.0 55 10 7.5± 5.7 10

P < 0.001 p < 0.05 We conclude that umbilical venous pul­sations are associated with increases in reverse flow in the IVC with atrial contraction and increases in perinatal mortality. Venous pulsations, which are detectable using simpler techniques than fetal echocardiography, probably reflect alterations in cardiac hemody­namics in the fetuses examined, and may assist in the identification of fetuses who would benefit from more detailed evaluation.

PERINATAL OUTCOME FOLLOWING IMPROVEMENT OF ABNORMAL UMBILICAL ARTERY VELOCIMETRY Shyamashree Sengupta, M.D., J.T. Harrigan, M.D. J. Rosenberg~ R.D.M.S., R.A. Knuppel, M.D., M.P.H. UMDNJ-Robert Wood Johnson Medical School New Brunswick, New Jersey

Abnormal umbilical artery velocimetry was followed in 128 patients. A mean systolic diastolic (SiD) ratio > 4 was considered abnormal. All patients were monitored by biophysical profile and growth parameters and placed on rest in the left lateral position Sixty-six (51.5%) patients had improvement of the SiD ratio (SiD <.. 4) • The outcome in the improved group was compared to 62 (49.5%) patients with persistent abnormal flow. The improved group exhibited no fetal distress or perinatal mortality compared to 24% fetal distress and 13% perinatal mortality in the group with persistence of abnormal flow. The mean diagnosis to delivery interval 63+14 days and mean gestational age at delivery 37+2 weeks were significantly greater in the imprOVed group. It was concluded that abnormal doppler velocimetry improves with bedrest in a large number of patients (51%) and was associated with an improvement of perinatal outcome.