324 SPO Abstracts

83 EFFECT OF LOW DOSE ASPIRIN (ASA) ON MATERNAL RENAL ARCUATE ARTERY. J.C. Veille. K. Tatum', IC. Keller. Dept. Ob/Gyn, Bowman Gray School of Medicine, Winston-Salem, NC. OBJECTIVES: Administration of low doee ASA may decrease the incidence of hypertensM: disorders in high-risk pregnancies. Maternal renal vasculature may be affected by such treatment. The purp<ll!C of this study is to document the waveform of the maternal reoal arcuate artety U8ing color pult!Cd Doppler. STUDY DESIGN: Flfty-nine patients were studied during their pregnanciea. Thirty-two (32) patients were on low dooe ASA from the 12th week onward (A). A group of 1:1 normal patients were UI!Cd as control (N). All patients had the right renal arcuate artety identified using color pult!Cd Doppler. All studies were done with the patient in the left lateral decubitus. Three to six cycles were recorded on a strip chart at a speed of 100 mm/l!Cc, digitalized and averaged. Non-paired t-test was done for comparison. RESULTS: There was no significant correlation between gestational age and the SID ratio, PI, RI, PFV or 1VI of the maternal right renal arcuate artety.

Mean GA 1VI AC/ET SID PI

N (27) 28 ± 7 18.8 ± 7 0 .14 ± 0.04 4.5 ± 4 1.2 ± 0.3

ASA (32) 26 ± 6 16.5 ± 6 0 .16 ± 0.05 35 ± 3 1.3 ± 0.3 ..

P N NS NS NS NS

GA = gestational age (wks); 1VI = time velocity integral (cm); AC/ET = acceleration to ejection time; SID = systolic to diastolic ratio; PI = pullatility index. CONCLUSIONS: (1) Low dose ASA does not significantly affect the Doppler waveform of the ~ renal arcuate artety; (2) normal pregnancy does not seem to significantly alter the resistance of this particular maternal vascular bed. (Supported by Grant #HI..38296 from NIH, NIHLB).

84 ESTROGDt AND PIIOGISTIJIOftI RiCIPfORS I" TilE UTiRl1IE ARliRY

Of PRlGNAHr AND ItOIt-PRlGNAHr lIArs

J.I. Ltibtl'lllll, II. Wizni b.I', II.GIII'I'IIIII, B. f,ldun, J. --------------LtVII, Y. Sharoni. DI,. Ob I Gyn, Bioohtll. UnU, SOI'OU

Univ. Ho.,., BIn Gurian Univ., BIll' SlItn, lnul.

O&lICTlUI: tilt ai .. of tht .tudll IllS to u.us whtihtl' tht uill'ine vt.1",I is an ntl'O"n N.pon.itt tillUAt !Iv lIfuvin, n" Ilynlllie. of IStl'O"" anll '1'OII5t'l'On. Ne.,tOI'5 win, 'N!fJIaney.

STUD¥ DISIGH: Tilt .. i,ht 01 tilt utll'illl vt.1",I anel it. eont.nt 01 •• tl'O"n ind fl'O"st'l'Ont NC.,tOI'5 .. N MlUlINel Winy ,Ngnancy. Jht st'l'Oiel NC.,"I' cont.nt .as IItlSUl'tel • so in tht aOl't ••

mULfS: flit ut'l'inl vt.1",I .. i,M incNu.el lION than lourfolel in tilt lIiddl. of 'I'fgn",ey anel .vln Ivtlltl' tolflNs tht Inel 01 ,N!fJIaney. JM InCNlS. in "i,ht IllS PlI'lll.l to tilt ineNu, in tilt l.vII 01 ,llS" 1 -btta­estl'uiol. Durin, ,N!fJIanoy a clruatic ineNlS' .as dtt.ct.el in tilt nUMIIII' of ut'l'l"nl vt.1",I .sbo,.n I'fc.,tOI'5. tilt "tl'O,.n NO.,tOl' IVII IllS higllt.t at tel'll ,N!fJIancy anel ollo.in, bil'th dtcNlS.d to • 10. valu •• fM l.v.l 01 ,1'09I5t'l'On. NO.,tOH in tht ut'l'in. irt.1'Y incl'tlS.el lIOel.5tlYI thou,h Significantly clUI'iny ,NgnanclI, and I'OS' sttl, Y at pun,lI'iWt. No lIfanill"u ehU,fS "1'1 5t1n in tht &Ort ••

COtICLUSIOlt: lilt chan •• s ill tht "tl'09I11 Mel 'l'O"stel'OD' Ne.,tGl' 1.v.1s in tilt 1'.' utnill' vt'N WiA' anel alt.1' ~gnaney, su".st that tlltl •• tlroid aor.ea.s have a ~clOlllllant . 1'01. In tht 9JIO.th 01 tilt utll'in. vt.1",I win. p,.t.hon, and that tht N.t utll'in. vttl",l i •• tll'9tt tissul rol' 'Itl'09ln actlOll.

January 1993 Am J Obste t G ynecol

85 ASSESSMENT OF DIFFERENCES BE1WEEN FETAL AND NEONATAL HEART RATE V ARIABILI1Y BY POWER SPECTRAL ANALYSIS. R.M. Lewjnsky", S. Pansky", L.W. Oppenheimer", M.Sharf". Dept. Ob/Gyn Bnai Zion Med Center, Haifa, Israel and Ottawa General Hospital, Ottawa, Canada. OBJECTIVE: To compare patterns of spontaneous heart rate fluctuations in neonates and fetuses by employing power spectral analysis (PSA) of the ECG. SroDY DESIGN: The ECG of 12 term fetuses was recorded during labor and repeated within 48 hours from delivery. PSA of heart rate variability was done by applying a Fast Fourier Transform smoothed by a Hanning window to groups of 256 consecutive beats and was analyzed for the very low (0-0.05 Hz), low (0.05-0.15 Hz) and high (0.15-0.25 Hz) frequency bands. Results were Compared by paired t test. RESULTS: Total power was significantly higher in neonates when compared to fetuses (286 ± 178 vs 51 ± 27 msec'; p < 0.05). This difference correlated with (R'=0.576; p<O.OI) the higher amplitude of beat to beat fluctuations of the R-R intervals in neonates when compared to fetuses (67 ± 38 vs 29 ± 16 msec; p=0.03). Total power also correlated with the mean R·R interval (R2 = 0.432; p<O.OI). The distribution o( power was similar in fetuses and neonates (64 ± 20% vs 60 ± 21%; 26 ± 16% vs 31 ± 19%; 9 ± 7% vs 7 ± 5%) for the very low, low and high frequency bands respectively. CONCLUSIONS: PSA is a powerful and precise technique for the assessment of heart rate variability and shows that the early neonatal period is characterized by increased beart rate variability when compared to the intrapartum fetal state.

86 THE EFFECT OF AMNIOTIC FLUID ON PLATELET FUNCTION. KS Puder,x SM Berry, RS Alshameerix, HM Wolfe, SF Bottoms, Y Sorokin, and EF Mammenx. Department of OblGyn, Wayne State University, Hutzel Hospital, Detroit, MI. OBJECTIVE: Platelet counts obtained by cordocentesis are the basis for important clinical decisions. Our aim was to determine how amniotic fluid alters platelet function. SI'UDY DESIGN: The effects of amniotic fluid from 11 healthy gravidas at 23-39 weeks were compared to those of saline in this pilot study. Spontaneous and stimulated platelet aggregation in whole blood was measured using impedance. Primary platelet plug formation was evaluated using the Thrombostat 4000e ,an in vitro assay of bleeding time • RESULTS: There was no spontaneous platelet aggregation. Stimulated platelet aggregation increased with addition of amniotic fluid, but remained in the normal range

Difference p Platelet collagen 2.9±3.5 < 0.02 Aggregation ADP 4.4±3.0 < 0.001 (ohms) arachidonic acid 0.77±3.0 N.S. Thrombostatin 50% amniotic fluid > 168±oo < 0.01 Time 30% amniotic fluid 76.5±80.8 < 0.05 (seconds) 20% amniotic fl)lid 37.6±70.3 N.S.

CONCLUSION: The findmg that aauuotlC flUid markedly increased Thombostatin times with minimal effect on platelet aggregation implies decreased platelet adhesion. These results form the basis upon which to study the effects of amniotic fluid on fetal platelet function.