Volume 164 Number 1, Part 2

304 A PROSPECTIVE STUDY OF UMBILICAL VELO­CIMETRY AND P~RINATAL OUTCOME IN INTRA­PARTUM FETAL STRESS PATTERNS: DOTUN OGUNYEfn, MD*, MILTON LEE, rm, KINGI DREW MEDICAL CENTER, LOS ANGELES, CALIFORNIA.

Fetal umbilical artery waveform were determined on 57 intrapartum patients with late decelerations, variable de­celerations, decreased variability or complicated baseline changes. A mean SiD ratio of ~ 3 after 30 weeks gesta­tion was taken as abnormal. GROUP NORMAL SiD ABNORMAL SiD NO 46 11 low 1 min AP 3(6.5%) 6(54.5%) low 5 min AP 0 1(9%) ACIDOSIS 2 7(63~) SGA 0 2(18%) NICU 1(2.1%) 4(18%) HOSP days 2 3(6.5%) 9(81.8%) Neo morbidity 1(2.1%) 7(72.7%) Neo mortality 0 1(9%) MEC below cords 1(2.1%) 3(27%) Adverse outcome 5(10.8%) lO(90%)P~0.01 The sensitivity, specificity, positivp­and negative predictive values of SiD ratios were 66.6%,97.6%,90.9% and 89.l% respectively. This suggest that um­bilical velocimetry is helpful in de­termining true distress in labor.

305 UMBI LI CAL ARTERY SURVEI LLANCE IN Till N PREGNANCY

Beattie RB X. McDowell MJ X. Ritchie JIIK.

Mount Sinai Hospital, 600 University Avenue, Toronto Toronto General Hospital, 200 El izabeth Street, Toronto

Umbi 1 ical artery waveform survei llance has been reported to predict discordant growth in twin pregnancies. 188 twin pai rs were reviewed with regard to abnormal biophysical profi le score (BPS<8/8), discordant estimated fetal weight (dEFII>25%) abnormal or discordant unbi 1 ical artery SO ratio (dSD> .4) and subsequent feta 1 outcome in terms of di scordant birthweight (dBIIT>25%), hypoxia and perinatal mortal ity (PNM). Utilising data from 134 examinations within 2 weeks of del ivery, discordant EFII was the best predictor of subsequent di scordant bi rthwei ght. Neonata 1 hypoxi a (apgar <4 at 1 minute, <7 at 5 minutes) was well predicted by an abnormal SO ratio and abnormal BPS whi lst discordant SO ratios were poorly predictive of any of these outcome parameters.

OUte.., Test Prey Sig Sens Spec PPY NPY

Hypox a BPS .11 * .40 .90 .33 .92 Hypox a dEFIi .11 .40 .87 .29 .92 Hypox a dSD .11 ** .27 .98 .57 .91 PNM BPS .06 * .38 .89 .18 .96 PNM dEFIi .06 .50 .87 .20 .96 PNM dSD .06 NS dBIiT BPS .13 * .33 .90 .33 .90 dBIiT dEFIi .13 ** .61 .91 .52 .94 dBIiT dSD .13 * .17 .97 .43 .88

NS not s i gni f i cant, *p<. OS, **p<O. 001

spa Abstracts 329

306 A COMPOUND ANALYSIS OF UMBILICAL ARTERY VELOCIMETRY IN LOW RISK PREGNANCY. Beattie RB x, Hannah M, Dornan JC, Womens College Hospital, 96 Grenville St., Toronto, Ontario.

Umbilical artery velocity waveform analysis has been justified in the surveillance of high risk pregnancies. The effect of a higher prevalence of adverse outcome in high risk pregnancies invalidates the assumption that it is also of value as a screening tool in low risk pregnancies. To date there are only five prospective blinded studies of this technique as a screening tool in low risk pregnancies. We present a compound analysis of the available data in this field including our own study of 'lIYJ7 pregnancies. The outcome variables include intrauterine growth retardation based on birthweight « 10th, 5th, 3rd and 2.3rd centile), low ponderal index or skinfold thickness, polycythaemia, low Apgar score or cord artery pH and intervention for fetal distress. Prevalence independant likelihood ratios have been calculated in these studies for varied thresholds for defming an abnormal waveform and for each outcome parameter such that direct comparisons can be made between studies. It is clear from this critical analysis of the published literature that there is concurrent proof that umbilical artery velocity waveform analysis is of no value in the unselected/low risk population and it should therefore not be introduced into clinical practice as part of routine antenatal care.

307 IS DOPPLER VELOCIMETRY USEFUL IN PREDICTING ADVERSE FETAL OUTCOME IN PREGNANCIES COMPLICATED BY OLIGOHYDRAMNIOS? deVeclana M ,X Major,C A , Nageotte, M P , Univof Calif., IrVine Med Center and Memorial Medical Center of Long Beach, Caflfornia

OligohydramniOs (oligo) IS known to be associated With increased perinatal morbidity and mortality The purpose of thiS prospective study was to evaluate the usefulness of Doppler Veloclmetry(DV) as an adjunct to conventional antepartum testing In patients with oligo Umbilical artery DV measurements were routinely performed In a blinded fashion on all patients undergOing antepartum testing The criteria for admiSSion into thiS study were 1) ultrasound documentation of oligo (AFI<5 0) , and 2) doppler measurements Within 7 days of both the low AFI and delivery 49 patients met these criteria. The pallents were diVided Into 2 groups based on the results of their doppler SID ratios. Group 1 consisted of all patients With ratios >30 (N=13) Group 2 consisted of all patients With SID ratios <3.0 (N=36) AFI, GA at delivery, BW, intrapartum fetal distress, CIS rate for fetal distress and NICU admlssons were compared between the 2 groups. The 2 groups were found to have no statistically significant difference in GA at delivery or mean AFI There was a statistically Significant difference In BW(p<.005) , intrapartum fetal dlstress(p< 009). rate of CIS for fetal distress(p<.009) and NICU admissons(p< 005) The senslllvlty, speCificity, positive and negative predlcllve values of the NST, DV, and both tests combined in predicting intrapartum fetal distress are shown below'

~ ~ ill ·PV Nll 27% 100% 100% 76% DV 61% 85% 61% 80% Combined 33% 100% 100% 83% CONCLUSIONS: patients with oligo and an abnormal DV are more likely to have a low BW Infant, fetal distress in labor,and a CIS for fetal distress DV appears to be more accurate than an NST In Identifying pallents who Will have intrapartum fetal distress When both the DV and NST are normal or abnormal, the posilive and negative predictive values of the tests combined are Improved over 1he use of the tests independently Thus, the concurrent use of both tests may aid In Intrapartum management of patients with oligo.