Fetal aortic to middle cerebral artery resistance index ratio: An indicator of normal and pathologic arterial blood flow distribution

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FC2.21.03 PREGNANCY INDUCED HYPERTENSION (PIH) AND ALTERED FRACTAL CORRELATION BEHAVIOR IN FETAL HEART RATE (FHR) VARIABILITY J. Y. Lim , I. Noh, E. Song, M. Im, B. Lee, .I. Hwang*, M. Park*, M. Yom** Dept. OB/GYN, Inha University, Inchon, Korea. *Dept. OB/GYN, Hanyang University, Seoul, Korea. **Dept. Ped., Hanyang University, Seoul, Korea. Objectives: The aim of this study was to test whether the statistical, spectral irregular, and fractal correlation behaviors in FHR variability may be changed in the fetuses of PIH mothers. Study Methods: Sixty fetuses who aged over 30 weeks and were not associated intrauterine growth restriction and whose mothers had mild PIH were studied. Three hundred gestational age-matched normal control fetuses were also included. We selected 5000 points of their FHR and calculated the power spectrum, approximate entropy short-( a1 s 8Obpm) and long- (a2 > 8Obpm) term fractal scaling exponent. The approximate entropy, a1 and aZ reflect irregularity, short-term correlation and long-term correlation, respectively. Results: There were no significant differences in the mean (143bpmk0.4 vs 141.9bpml.l), variance (43.2bpmz*2.2 vs 47.8bpn&5.9), low(131.0msecz*.5.6 vs 138..5msecz*12.2) and high-(23.7msedkl.O vs 27.7mse&2.1) frequency power, and approximate entropy(0.71&0.011 vs 0.732*0.025) of the FHR between the mild PIH and the control group. However a1 of the PIH group was significantly lower than a1 of the control group (1.368*0.015 vs 1.481*0.006, pcO.0001) but aZ of the PIH group was significantly higher than aZ of the control group (0.926*0.022 vs 0.78&0.012, pcO.0001). Conclusions: Among the various heart rate variability indices, only short and long-term fractal scaling exponent showed significant differences between the FHR of fetuses of mild PIH mothers and that of normal fetuses. PIH makes FHR less temporally correlated on short-term scale and more temporally correlated on long-term scale.

FC2.21.04 FETAL AORTIC TO MIDDLE CEREBRAL ARTERY RESISTANCE INDEX RATIO: AN INDICATOR OF NORMAL AND PATHOLOGIC ARTERIAL BLOOD FLOW DISTRIBUTION J. Aranvosi, T. Major, .I. Zatik, P. Bettembuk, University Medical School of Debrecen, Hungary, POB.37, Debrecen, HBM, Hungary, H4012. Objective: To establish reference ranges for the resistance index ratio of fetal descending aorta and middle cerebral artery (ACRI) and to describe the perinatal outcome of high-risk pregnancies, where the abnormal ACRI was applied as an indication for labor induction. Patients, methods: 164 patients with uncomplicated pregnancies were recruited for the longitudinal assessment of Doppler indices in the fetal descending aorta and in the middle cerebral artery in order to establish the normal values of ACRI between the 28th and 41st weeks of gestation. A single cut-off value of 1.2 was calculated to separate normal and pathologic arterial blood flow distribution. The perinatal results of 78 high-risk pregnancies were described where the abnormal ACRI was used for labor induction. Results: The ACRI ratio of uncomplicated pregnancies is constant between 28 and 41 weeks. Increased incidence of meconium (24.3%), ominous cardiotocogram (62,8%), operative delivery for fetal distress (64.1%) and 5-minute Apgar scores <7 (10.3%) could be detected of the high-risk pregnancies with abnormal fetal ACRI ratio. Conclusion: While the constant value of ACRI during the third trimester of gestation reflects the normal fetal arterial blood distribution, the abnormal ACRI is associated with an increased incidence of suboptimal perinatal results. Abnormal ACRI may be considered as a potentially useful marker of impending fetal compromise

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FC2.21.05 AMNIOTIC FLUID INDEX FOR SCREENING LATE PREGNANCIES J.D. Seffah, J.O. Armah, Dept. OB/GYN, University of Ghana Medical School, Accra, Ghana Objective: To find out whether Amniotic fluid Index (AFI) could be used to screen late pregnancies which presented at the clinic for the first time for adverse outcome. Study Methods: Design: Retrospective study that compared patients with AFI zz5 with those with AFI ~5. Setting: Korle Bu Teaching Hospital, Accra Patients: 1 111 consecutive cases referred to the ultrasound unit for the first time after 36 weeks of pregnancy between l* January 1997 to 31* December 1997. Main outcome measurements: AFI and rate of induction, Caesarean Section; and incidence of fetal distress. Results: Out of the 1 111 patients, 350 had AFI <5 and 761 had AFI 25. The relative risk for induction and Caesarean Section were 6.08 and 3.38 respectively. The relative risk for developing fetal distress was 8.48. The sensitivity was 79.6% and the specificity 89.5% in using AFI <5 for predicting fetal distress. Conclusions: The results indicate that AFI <5 could be used to screen late pregnancies for fetal distress

FC2.21.06 EFFECT OF FOETAL MONITORING ON MODE OF DELIVERY AND PERINATAL OUTCOME. R.Misra. U.Barman, M.L.N.Medical college, 144/367 New Mumfordganj, Allahabad, U.P., India, 211002. Aims and objectives: To ascertain whether electronic foetal monitoring, bio physical scoring,and doppler blood flow studies had any effect on the caesarean section rate,when multiple factors that affected caesarean section frequency were taken into account simultaneously. To find out how foetal monitoring affected foetal salvage. Study methods: The study was carried out in the department of obstetrics and Gynaecology M.L.N.Medical College Allahabad,India on 500 patients where 400 patients formed Group1 who had electronic foetal monitoring and bio physical scoring done on 100 cases of High Risk pregnancy and lOOcases of Normal pregnancy .200cases of this group were emergency admissions and were not monitored. Group2 comprised of 100 patients where 50 patients were High Risk pregnancy who had doppler studies,and 50 patients had no doppler studies. Results: In the first group of patients ,caesarean section rate was 75% and 33% in monitored group, while it was 35.5% in unmonitored group.Therefore monitored group with no high risk factor had caesarean section rate equal to unmonitored group.Perinatal mortality was 5/1000 in monitored high risk and normal monitored group of patients, while it was 35/1000 in the unmonitored group. In group 2, fifty cases of high risk pregnancy had a caesarean section rate of 60% while in the group who had no doppler study the caesarean section rate was 36%.The foetal mortality was 4% in high risk group in two patients one of whom had severe diabetes and the other one developed eclampsia. Conclusion: The hospital caesarean rate was about 35% in both groups of unmonitored patients and 33%in normal monitored group of patients in group1 showing that foetal monitoring does not affect the caesarean section rate, whereas the rate was much higher in the monitored high risk group of patients(75&60%) However, foetal salvage was remarkable in the monitored group of patients.

FC2.21.07 COMPUTER EVALUATION OF INTERNAL VERSUS EXTERNAL FHR MONITORING IN THE MINUTES PRECEDING DELIVERY D. J. Bernardes, A. Reynolds, J.P. Saraiva, C. Santos, L. Pereira-Leite. Dep. Ginecologia e Obstetricia, Hospital S. Jofo, Dep. Bioestatistica e Inform6tica MBdica, Faculdade Medicina do Porte, Portugal. Objective: To evaluate, by means of a computer program for cardiotocogram analysis, the main differences between internal and external FHR signals obtained in the last 40-60 minutes before delivery. Study Methods: Seventeen consecutively enrolled women were monitored during the last 40-60 minutes of labor and until delivery of the fetus, using