Volume 166 Number 1, Part 2

149 PROSPECTIVE ANALYSIS OF MALFORMATIONS DIAGNOSED BY ULTRASONOGRAPHY IN CHROMOSO­MALLY ABNORMAL FETUSES. B.R. Elejalde, xJ .M. Acufia, xM.M. de Elejalde, Medical Genetics Institute, S.C. Milwaukee, WI.

2,547 patients underwent prenatal diagnosis, 15 had a chromosomal abnor­mality other than trisomy 21. 6 had trisomy 18, 4 were 45,X, 2 were triploid­ies, 1 had trisomy 9, 1 was a trisomy 13 and 1 had a ring 14. 147 abnormal i ties were found by ultrasonography (US) before the karyotype was known. 203 abnor­malities were found postnatally. The 56 that were not found by US were divided into: 1) recognizable by US (9), 2) recognizable under special circumstances (14), 3) not recognizable by US (33) and 4) not recognizable postnatally (9). Out of 156 diagnosable by ultrasound, 147 (94.2%) were diagnosed. If those recog­nizable under specific circumstances are included, 147 out of 170 (86.5%) were diagnosed. Syndromic diagnosis, before karyotyping, was correctly done in 4 trisomies 18, 2 triploidies, 1 trisomy 13 and 3-45,X. The above distribution of abnormalities defines ultrasound resolu­tion and the bases for quality control

150 PROSPECTIVE STUDY OF THE ULTRASONOGRAPHIC RESOLUTION OF NORMAL FETAL CHARACTERISTICS. B.R. Elejalde, xM.M. de Elejalde. Medical Genetics Institute, S.C. Milwaukee, WI.

3,900 patients underwent 8,200 ul trasonographic examinations. Fifty one structures were measured, 68 ossification centers and 173 anatomical structures were scored as: seen, not clearly seen, not seen, not present and abnormal. Nineteen patterns of fetal activity were similarly recorded and their frequency scored. Only normal pregnancies 10 to 39 weeks were included. Descriptive statis­tical analysis was used for the analysis of each one of the 311 items per week. centiles 1st to the 99th were established for each measurement and week. A table including the characteristics for each week based on this analysis was con­structed and constitutes the bases to determine the mean and the range of expected results of the fetal ultraso­nographic examinations at weeks 10 to 39. They define the bases to determine the levels of ultrasound resolution. Resolu­tion is affected by the knowledge of the operator, obesity and fetal position.

SPO Abstracts 321

151 AMNIOTIC FLUID VOLUME ASSESSMENT IN HUMAN PREGNANCY:

152

COMPARISON OF SONOGRAPIIIC ESTIMATES VERSUS DIRECT MEASUREMENTS USING A DYE·DILU11ON TECHNIQUE. Gary Dildy, Nne Lirax, Kennelh Moi.<.c Jr, Gerry RiddlcX., Russell DCH...-rx , Department of Obstetrics and Gynecology, Baylor College of Medicine. Houston. Texas.

Abnormalities in amniotic fluid volume (AFV) arc associated with pOOl

perinatal outcomt.:. The purpose of this study was to compare the accuracy of indirct.:t n:al Lime sonographi':. techmques of AI'V assessment with a direct technique of AI;Y measurement. METHODS: A water-soluble dye (aminohippuratc sodium) was instilled into the amniotic sac of women undergoing amniocentesis for fetal lung maturation during the third trimester. Thlftcen distinct serrDquantital1ve sonographic techniques in both the :.upine and lateral recumbent po~iti()m, including the amniotic flUid index. (AFt), were performed. A sel-ond amniocentesIs wa~ pnformcd to determine dye conccntrdtion in order to calculate actual AFV. Optimal polynomial regression functions of sonographic measurements (independent variable) versus actual AFV (dependent variable) were determined. Predicted AFV was calculated by mtroducing the value of the sonographic measurement into the equation. The percent difference between the actual and predICted AFV was determined for each measurement, and the mean, standard deviation, and 95% range were calculated. The Student t-test, ANOVA, and F-lcst were used to determine dliTerenccs octwecn techniques, with p<O.05 considered significant. RESULTS: 50 pallents were enrolled into the study. Mean actual AFV as determined by the dye technique was 1066 ml (mngc 129 to 4444 mJ). Mean AH wa.<; 16.4 em (range 2.7 to 31.3 em). The fl'gression equation for the AFl technique was: y =

-713 + 258x. -17.1x.2 + 0.437x3; R2:::: 72.1%. mean percent error:::: 11.5%, standard deviation of percent error = 53.0%, and 95% range of percent error was -51.7 to 103.7(10 . Among the 13 tf.:chniqucs. there were n,-) ddfercnces in mean error as detnmined by ANOY A. Four of the ll.chniqucs show..:d a stali~I.J("a1ly

slgnific,lIlt [l;(Juctwn in sL.lIldruJ de\ lation or error a:-. ddermined by the i'-lest, whcn compared to the AH CONCl.USIONS The AH ll\'cn~stin1dtcd the actual AI;V by as much <l." lO4 % at Inw rangc!> and undcre~timJ.tcd the actual Al-'V by a." much as 52 %, esptTlally dl higher rangcs. Although there were statistically signifi.cant rcductions in measurement CITOT arrx)Jlg ~t:vera1 or the sonographic methods eompan'd to the AI-I. these differences did not appear sufticitnt to ~commL:nd ch,mgcs in current clinical practice.

SERIAL HWRLY FETAL URINE PRWUCTlOII IN FETUSES IIITH BILATERAL HYDRONEPHROSIS. SJ Carlan, 0 Adkins', M Gore', 0 Mastroglannls, Depts Ob/Gyn U of S FL,TarTl'a, FL, ORMC, orlando_

Since some ultrasound detected fetal hydronephro::.is,(H), cases are not present after birth, it is possible that this finding my be functional and related to the greater urine production in the fetus c~ared to the neonate. The purpose of this study \.las to compare hourly fetal urine production (HFUP) in fetuses with bi LateraL H to a group of normaL fetus­es. Fourteen normal fetuses and five fetuses wi th bi -lateral H were scanned seriaLLy from 20 \.Ik.s untiL delivery, and HFUP measurements were attempted. All fetuses with H had major calyceal system dilatation with kidney longitudinal Length\ coL Lecting system Length ratios >30% for both kidneys through­out gestation. There were no detectible cases of hydroureter or extrarenal anomal i es in ei ther group. There was n:J di ffer­ence in fetal kidney length or AFl during gestation. GLucose screens were performed on al l women, and there were no mater­nal disorders il1 either group. There was no significant dif­ference in maternal age, GTPAL, smok i n9 or C- sect i on rate. Mean BU was 2979 and 3569 for the H group and normaL group respec­tively. NeonataL urologic workup in the H group was normal in all cases except one infant with persistent hydronephrosis (this fetus aLso demonstrated minor calyceal dilatationL

WKS 20 22 24 26 28 30 32 34 36 38 40

N 5 5 5 5 5 4 4 4 3 3

SERIAL HFUP cc/hr (MEAN ,1SO) Bi lateral H N Normal 3.6 t 1.J 14 4.1t1.9 4.8 ± 1.2 14 5.0 ± 1.7 9.8 ± 2.7 14 8.3 ± 2.7 12.2 4.1 14 10.6 ± 3.6 12.4 ± 3.0 14 15.5 ± 4.2 20.5 ± 4.6 13 23.6 ± 4.7 24.7 ± 4.1 13 28.9 ± 5.6 24.6 ± 3.8 13 37.3 ± 12.2 37.1 ± 7.7 13 43.8 13.9 39.2 ± 8.3 8 58.3 ± 21.9

o 8 47.9 ± 12.9

NS NS NS NS NS

NS NS NS NS NS

Ue conclude that fetuses \.11th uLtrasound detec.ted biLateraL H have simi lar HFUP as fetuses wi thout bi lateral hydronephrosis.