354 SPO Abstracts

198 EARLY AND SIMPLE DETERMINATION OF ZYGOSITY OF MULTI FETAL GESTATIONS INTHE FIRST TRIMESTER BY HIGH FREQUENCY TRANSVAGINAL SONOGRAPHY. A. Monteagudo, I.E. Timor-Tritsch. Dept. Ob/Gyn, Columbia University, New York, NY OBJECTIVE: To evaluate the hypothesis that an early, high frequency transvaginal sonogram at 7-10 weeks correctly determines the number of chorions, amnions as well as the proximity of cord insertions in cases of multifetal gestations. STUDY DESIGN: One hundred forty-two multifetal pregnancies were evaluated by transvaginal ultrasound probes ranging from 5-7.5 MHz. All but four pregnancies were the result of induction by hormonal agents. In each pregnancy the following was assessed: the number of fetuses, the number of chorions and the number of amniotic sacs within each extraembryonic space as well as the exact site of the placental cord insertion. RESULTS: Two septuplet, 2 sextuplet, 14 quintuplet, 38 quadruplet, 70 triplet and 16 twin pregnancies were scanned. In all pregnancies, chorionicity and amnionicity was established. Two quadruplet, 3 triplet pregnancies had monochorionic diamniotic twins along with one or two other normal monochorionic, monoamniotic fetuses. Four twin pregnancies were monochorionic. One set of triplets was also found to be in the same chorionic sac. CONCLUSIONS: During the entire flfst trimester, the clarity of the imaged structures such as hyperechoic chorion, the thin amniotic sac surrounded by the extraembryonic coelom containing the yolk saclsacs and the ease of tracking the umbilical cords back to their placental insertion enable exact determination of chorionicity and amnionicity of the involved fetuses. Management of these cases in accordance with knowledge of zygosity can be planned early, in the flfst or very early second trimester. The early detection of zygosity is important at the planning of eventual multifetal reduction. If the pregnancy is continued, it will play an important role in the second and third trimester management of the fetuses.

199 ULTRASONOGRAPHIC PREDICTION 0.. FETAL LUNG MATURITY. J.R. Loret de Molax , N. Judge, C. EntsmingerX, M. DeVineyX, K. Muise, M. Duchon. Dept. Reproductive Biology, Case Western Reserve University and Dept. Ob/Gyn, Univ. Hospitals of Cleveland, Cleveland, OH. OBJECTIVE: To correlate fetal morphometrics with a mature amniocentesis. STUDY DESIGN: 91 patients undergoing amniocentesis for fetal lung maturity were examined prospectively. Fetal morphometrics were obtained prior to amniocentesis, including mean gestational age, biparietal diameter, head and abdominal circumference, femur length, distal femoral, proximal humeral and tibial ossification center size. Fetal evaluation included colonic and placental grades as previously described. Discriminate analysis was used to identify variables that were predictive of a mature LIS ratio and PG presence. RESULTS: 27 (29.6\) fetuses had a grade 3 colon, which was found to be 96.2\ sensitive and 69' specific for a mature amniocentesis. Discriminate analysis revealed that colon grade was the single best predictor of a mature amniocentesis (P<0.001). The distal femoral epiphysis was the next best predictor (p=O. 107) of mature amniocentesis. Fetal morphometrics did not predict a mature amniocentesis. CONCLUSIONS: These data suggest that a grade 3 colon is predictive of a mature amniocentesis, and may provide reassurance when amniotic fluid analysis is not feasible.

January 1993 Am J Obstet Gynecol

200 DOPPLER STUDY 0.. ACUTE HEMODYNAMIC E .... ECTS INDUCE~ BY CHORIONIC VILLUS SAMPLING. ~ zoppini, A. Donnenfeld, L. Goanilow, A. Ludanirsky, S. Weiner. MFM Section, Pennsylvania Hospital, Phila, PA. OBJECTIVE: To evaluate the effects of chorionic villus sampling (CVS) on the fetal umbilical artery pulsatility index (UAPI) and the maternal arcuate artery resistance index (AARI). STUDY DESIGN. Pulsed Doppler UAPI and AARI measure­ments were obtained prior to and ilIInediately following CVS in 35 patients. Results were cCXlpared to UAPI and AARI measurements obtained at the beginning and end of ultrasound examinations in a group of 35 gestational age-matched controls. CCXlparisons within groups were performed using paired T-tests, mean changes between groups used two-sample T-tests, and variance analysis between groups was performed using ,,-tests. RESULTS. The mean change (SO) in UAPI _s 0.07 (0.59) and 0.08 (0.37) for the CVS and control groups,respec­tively. Within groups these mean changes were not 8ta­stically different fran zero. Between groups, the mean UAPI changes were also not statistically different. However, the variance around the mean UAPI changes _8 2.5 times larger in the CVS group canpared to the control group ("z2.5, df=34,34 pcO.009). There was no significant difference in mean AARI change or variance around the mean AARI change between groups. CONCLUSIONS, The CVS procedure was associated with larger positive and negative changes in umbilical artery pulsatility index than in the control group. In contrast, CVS had no significant effect on maternal arcuate artery resistance index.

201 EFFECT OF POSITIVE COCAINE TOXICOLOGY ON UTERINE ARTERY DOPPLER VELOCIMETRY. Q, Ogunyemi", R. Cook", S. Beverly", P. Brown", T. Fukushima. Dept. OblGyn and Radiology, KinglDrew Medical Center, Los Angeles, CA. OBJECTIVE: To evaluate the effect of positive cocaine toxi­cology on uterine artery velocimetry in pregnant drug abusers, STUDY DESIGN: Twenty eight women at 28-32 weeks gesta­tional age had SID of right (RUP) and left (LUP) proximal, right (RUD) and left (LUD) distal uterine arteries calculated on Doppler velocimetry. Twelve women had positive cocaine screen, 11 were known drug abusers with negative screen, and S were normals. ANOVA and student Hest were used for statistical analysis. RESULTS: When compared to the other groups, the positive cocaine screen group showed significant elevation of the mean uterine artery SID (p<0.01)' RUP (p<O.OS)' and RUD (p < O.OS), but not LUP, Overall, there was a significant decrease in the RUD (SID = 2.17) as compared to RUP (SID = 2.61 [p < O.OS]), but no difference between LUD (SID = 2.4S) and LUP (SID = 2.S6). In the positive cocaine and drug abuser groups there was no difference between the proximal and distal uterine artery SID; however, LUD was higher than LUP in the positive cocaine patients. In normal patients RUP was significantly higher than RUD. CONCLUSION: This study suggests that cocaine may have an overall vasoconstrictive effect on the uterine vessel and may also diminish resistance gradient between proximal and distal segments of the uterine artery.