201

334 spa Abstracts

FE:fAL INTRACARDIAL EFFECT OF MATERNAL INGFSTION OF LOW DOSE ASPIRIN (ASA). J.C. Veille, R. Hanson, M. Sivakotl, M. Swain, L Henderson, Dept. of Ob/Gyn, Bowman Gray School of Medicine, Winston-Salem, NC and CWRU, Cleveland, OH·.

Chronic maternal ingestion of low dose ASA may have significant effects on fetal intracardial blood flow velocity (lBI-V). Even though it has been assumed that no or minimal effects occur in the fetus, data are lacking. IIlI·V using pulsed Doppler was assessed at3 different gestational age (GA) periods: Group (GRP) 1= 12·23; II = 24·32; III = 3341 weeks) in fetuses exposed to ASA. Fetuses not exposed to ASA were used for control (C). A total of 230 studies (ggc; 51 ASA) were done. Results are as X.:t SEM. An ANOYA was used to assess any differences between each GRP.

GRP 1VIVI 1VIVI MVIVI MVIVI 4.4 ± 0.2 3.9 ± 0.3 4.9 ± 1.2 3.7 ± 0.2'

II 6.1 ± 0.2 6.5 ± 0.9

41.5 ± 2 37.4 ± 2 36.9±I' 33.9 ± I' 50.7 ± 2 45.7 ± 2 46.9 ± 12' 42.6 ± 8·

III 56.6 ± I 60.3 ± 3 46.7 ± I 43.5 ± 4

UJI < 0.0000 < 0.000 0.00 .0000

Legend: 1VJV1 = Tricuspid valve time velocity integral; MY = Mitral valve; PI-V = Peak flow velocity (cm/sec); C = control; ASA = Aspirin. Results: (1) PFY and TVI across the tricuspid valve t significantly with advanced GA in both the C and ASA. No difference within the groups was found. (2) MY TVI did not significantly t with GA in the C GRP. In the ASA, 1VI significantly t during the 2nd GA period. No difference was documented, however, within each GA group. (3) MVPFY significantly t in the C and ASA GRPS during the 1st to 2nd GA period. Conclusions: Even though major changes were seen in intracardial blood flow with advancing GA, NO DIHt:RENCE was documented between the C and ASA GRPS. (Supported by NIH Grant 11(38296).

202 LOW MIDDLE CEREBRAL ARTERY (MCA) RESISTANCE INDEX OF POURCELOT (RI) PREDICTS NEONATAL MORBIDITY IN POST·TERM PREGNANCIES. J. Shyk('n, S. Lieberman', A. Kivikoski', J. Smeltzer, Dept. OB/GYN, Washington Univ., St. Louis, MO

Uterine and umbilical artery vclocimctry has not proven useful in management of prolonged pregnancies. There is little information regarding the value of MCA Doppler for this purpose. Forty·seven well-dated pregnancies at 2:..41 weeks gestational age w(-'rc prospectively studied to define the relationship between fetal cerebrovascular resistance as measured by MCA-RI, umbilical artery pH, and occurrence of abnormal pregnancy outcomes. Two groups were identified: those with normal outcomes and those with neonatal morbidity (having two of the following: umbilical artery pll < 7.2, low 1 minute Of 5 minute Apgar score, or neonatal intensive care unit admission). Eight of 47 infants had significant neonatal morbidity. The n('rmals diITered from the abnormals only by mean MCA values (0.74 + .01 versus 0.64 + .oa, t=2.98, p<.005) and gestational age in ;:eeks (41.8 .:t .08 ~ersus 42.3 .:+:. 0.1, t=·2.58, P < .02). Gestational age and MCA·RI together clearly delineated those with neonatal morbidity from others by discriminant analysis. Cutoff values for MCA·RI and their corresponding systolic to diastolic ratios (SID) for each gestational age were calculated (using the formula RI = 0.14(gestational age) . 5.16) to obtain 100% sensitivity.

Weeks Gestation RI SID 41 < .58 2.:J8 42 ~.72 :1.57 4a <.86 7.14

For these cutoff values, sensitivity -;as 100%, specificity 74.4(}(}, and positive predictive value of 44.4%. Further, MCA·RI predicted umbilical artery pH (R2 =0.22, p=.G.1). CONCLUSION: MCA Doppler indices are helpful in the management of post· dates pregnancies, and low RI values as ind~catcd portend neonatal morbidity.

January 1992 Am J Obstet Gynecol

203 UTERINE ARTERY DOPPLER mOCIMETRY, PLACENTAL PATHOLOGY AND PERINATAl OUTCOME. E. Ferrazzi " G.P. £ulfamante " A. Barbera', A. Pavesi " and G. Pardi. Dept. Db/Gyn, Dept. Pathology, San Paolo Biomedical Science Institute, University of Milan, Italy.

The placental morphology ~as analyzed In 21 pregnancies ~Ith abnormal longitudinal uterine doppler SID ratio (abn. SID) and in 15 pregnancies ~ith normal uterine SID ratio (nor. SID). Nine patients ~1th abn. SID developed pregnancy Induced hypertension (PIH). All fetuses ~ith abn. SID ~ere gra~th retarded in utero (!UGR). 3 fetuses only ~ith nor. SID me !UGR (see Table-top). In the normal pregnancy-nor. SID group, only -'8l of the placentas showed haematoma and III had trophoblastic hischemic lesions. IUGR fetuses with nor. SID sho~ed similar normal placentas. In the IUGR group with abn. SID, placentas sho~ed Similar lesions to those observed in IUGR-PIH group ~ith abn. S/D.: large infarcts (4U vs.55l), abruptio placenta (8l vs m), placental hematoma (15l vs m) and trophoblastiC hlschemic changes (83l vs 100l). Table-body shows the perinatal results in the 4 groups:

PREGNANCY NORMAL IUGR IUGR UTERINE SID NOR. NOR. ABN. N. CASES 11 3 11 ABN.UMBILICAL PI 7 FETAl DISTRESS 5 P.N. DEATH I DELIVERY WEEK 38(1) 39(1) 33(3) CESAREAN SECT. 11 NEWBORN WEIGHT 3195(456) 1323(1301 1581(545)

!UGR - PIH ABN. 9 7 3 2

19(1) 7

896( 376). !UGR with abn. SID are at greater risk of placental lesions and related abnormal outcome.

204 THE PERINATAL SIGNIFICANCE OF ABSENT END DIASTOLIC FLOW IN DISCORDANT TWINS . .fi.....JlWr,x J. Crowley,X K. H-WiUces,x M. D'Alton, Dept. of MFM, St. Margaret's Hospital, Tufts University, Boston, MA

Over two years 50 pairs of twins demonstrated discordant fetal growth by ultrasound with intrapair estimated fetal weight difference of at least 20%. All sets had serial growth scans and wnbilical artery Doppler studies. Of the 50 pairs 37 had DOrmal Dopplers. 13 pairs demonstrated absent eud diastolic flow (AEDF) in the smaller twin (4 with dichorionic and 9 with monochorionic placentation.) AEDF did not dictate delivery; however, intensive fetal surveillance with daily NST's AND BPP's were suggested by the perinatal team. The average gestational age at delivery was comparable between the groups with and without AEDF (33.0 wks. vs 33.8 wks.) There was no significant difference between disconIancy at delivery in the group with AEDF (26% ± 13%) and the groups with nonnal Doppler studies (25% ± 9%.) The overall perinatal survival was 94/100 (94%.) There were 6 perinatal deaths (4 IUFD's and 2 neonatal deaths) in the twins with AEDF compared with no deaths in the group of discordant twins with normal Doppler flow (p<0.001.) An additional 2 cases demonstrated multicystic encephalomalacia and seizures in the neonatal period. No serious neonatal morbidity occurred in the group with DOnnal Doppler flow. In conclusion AEDF identifies a subset of discordant twins who are at significant risk for perinatal death and adverse neonatal omcome.