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426 The use of fetal echocardiography for predicting intrapartum fetal distress in the postterm pregnancy
364
SPO Abstracts
426 rHE USE OF FETAL ECHOCARDIOGRAPHY FOR PREDICTING
NTRAPARTUM FETAL DISTRESS IN THE POSTTERM PREGNANCY Janet Horenstein. M.D, Greggory R. DeVore, M.D., and Lawrence D. Platt, M.D., LAC/USC Womens Hospital, Los Angeles, CA and Salt Lake City, UT. The purpose of this study was to determine whether fetal echocardiography would identify postterm fetuses at risk for intrapartum fetal distress Seventy-five postterm fetuses underwent antepartum testing [non-stress test (NST); umbilical artery Doppler velocimetry (UAD); and Amniotic flUid index (AFI)) and M-mode echocardiography in which the right and left ventricular dimensions (RVID, LVID), the biventncular outer dimension (BVOD), and the RVID/LVID were measured. Each fetus was examined for the presence or absence of a pericardlal effusion (PE). Fetal distress was defined as abnormal intrapartum heart rate tracings associated with physician Intervention (02 administration, fetal scalp sampling, emergent delivery) Emergent delivery was defined as cesarean section or Instrumented vaginal delivery for fetal distress. Group I (N=32) had no fetal distress In labor, Group II (N =23) had fetal distress in labor not requiring emergent delivery, and Group III had fetal distress In labor requiring emergent delivery Comparing Groups I with Groups II and III demonstrated the NST and UAD not to predict intrapartum fetal distress or emergent delivery. However, there were significant differences between Groups I and II for RVID, RVID/LVID, and PE. There were significant differences between Groups I and III for the above as well as LVID, BVOD and AFI Linear logistic regression analYSIS (Groups I, II, III), identified RVID/LVID, LVID and PE as significant variables for predicting fetal distress In labor BVOD and AFI were predictive for fetal distress associated with emergent delivery The results of the study suggest that in fetuses who develop fetal distress in labor (Group II. III). there initially is dilatation of the right ventricle which may be aSSOCiated with a pericardlal effusion, followed by dilatation of the left ventricle. Cardiomegaly (BVOD) and an abnormal AFI are late changes but predlcitlve of fetal distress requiring emergent delivery
427
CORRELATION OF THE AMNIOTIC FLUID INDEX AND THE NON-STRESS TEST IN THE PRE TERM PREMATURE RUPTURED PATIENT JA Harding, ON Jackson, OF Lewis, CA Major, MP Nageotte, T Asrat University of California, Irvine, Long Beach MemoriaL Medical Center The amniotic fluid index (AFI) has been investigated in the preterm premature ruptured membranes (PPROM) patient and felt to have a potential association with latency period and outcome. 50 patients were prospectively collected from 1989 to 1990 with PPROM and followed expectantly with daily one hour Non-Stress Tests (NST) and blinded daily AFI exam. A total of 422 AFI values were obtained and compared to daily uterine activity and presence of decelerations on the NST prior to the actual onset of labor_ The average AFI was 5_9 + 2_1 cm (Range 1_3 to 16_0) and the daily relative rate of change in AF I was 0 _1 !. _5 cm/day (Range 0-20)_ Nonlaboring uterine activity was not found to have a statistically significant correlation with the daily alteration in the AFI regardless of the fetal position, gestational age or parity (p=.11). A slightly lower AFI (5.3!. 1.7 cm vs. 6.2!. 2.2 cm) was associated with a statistically significant increase in fetal decelerations (p<.001). However, this difference is beyond the standard error of the AFI measurement. We conclude that in the PPROM patient the AFI is a variable quantity on a daily basis, nonlaboring uterine activity does not alter the AFI value signifIcantly, and subtle AFI variations are associated with fetal heart rate deceleration patterns. The daily NST provldes a more sensitive marker for development of clinically s;gniflcant changes in fluid volumes than the daily AFI in the PPROM patient and should remain a mainstay in the expectant management of these patients.
,J.ltlll.ln
19~1
Am J Obstet (;, newl
428 DELAYED MORBIDITY WITH ABNORMAL NONSTRESS
x TESTS. '!1. Blessed , and S Bottoms. Wayne State University, Hutzel Hospital, Detroit, MI. An abnormal (nonreactive or suspicious) nonstress test (NST) is usually further evaluated with biophysical profile, contraction stress test, or repeat NST. If these are normal, the NST is often considered falsely abnormal. To evaluate this interpretation, we studied 644 pregnancies followed with NST's, using only results occurring at least 7 days before delivery. Of these, 40 had at least one abnormal NST (ANST), but whose pregnancy was allowed to continue for at least 7 days based on follow-up testing. This group was compared to the 604 patients with all normal NST's (NNST). Gestational age at delivery (GA-DEL), birth weight, and a morbidity score (M-SCORE) based on meconium, cesarean delivery, low Apgar score, and NICU admission were analyzed with ANOVA, controlling for gestational age at NST (GA-NST), and using only one NST per pregnancy. GA-DEL GA-NST NNST ANST 30-31 37.8 36.8 32-33 38.4 37.4 34-35 38.9 37.8 36-37 39.5 38.9 38-39 40.3 39.7 40-41 41.6 41.0
BIRTHWEIGHT NNST ANST 3380 2620 3150 2990 3200 3110 3320 2950 3410 3850 3670 2990
M-SCORE NNST ANST 0.49 1.55 0.01 0.49 -0.10 0.03 -0.12 0.60 -0.04 0.57 -0.27 2.21
Patients with an abnormal NST deliver earlier (p
429 NST
-EXPERT: AN "INTELLIGENT" APPROACH TO THE NONS TRESS TEST (NST). L. Devoe, A. AlonsO. V. Moret~E. Ramos:B. Banias~ D. Sherline, J. Searle~Depts of OBGYN and Biomedical Engineering. Medical College of Georgia, Augusta, GA. We have developed an expert system, NST EXPERT, in IQ LISP, to aid evaluation and utilization of the NST. It uses selected demographic data and risk factors to assess significance of NST results, suggest further management and predict infant outcome (risks of death, fetal distress, 5-Apgar < 7 or acidosis). Prospective system validation used 177 consecutive tested high risk pregnancies; 4 perinatologists and NST-EXPERT assessed each case independently. Ranges of agreement among the perinatologists and those between NSTEXPERT and each perinatologist were, respectively, for NST evaluation: 80%-94% and 80%-93% ; for clinical management: 73%-93% and 80%-94%; for outcome predicted: 80%-100% and 83%-93%. The agreement between all outcomes predicted and obtained was 80%87% for perinatologists and 85% for NST-EXPERT; for bad outcomes predicted and obtained, 28%-48% for perinatologists and 88% for NST-EXPERT. CONCLUSION: An expert system has been created that appears to perform contextual analysis of the NST, to suggest management schemes and obtain prognoses at the level of a clinician.
SPO Abstracts
426 rHE USE OF FETAL ECHOCARDIOGRAPHY FOR PREDICTING
NTRAPARTUM FETAL DISTRESS IN THE POSTTERM PREGNANCY Janet Horenstein. M.D, Greggory R. DeVore, M.D., and Lawrence D. Platt, M.D., LAC/USC Womens Hospital, Los Angeles, CA and Salt Lake City, UT. The purpose of this study was to determine whether fetal echocardiography would identify postterm fetuses at risk for intrapartum fetal distress Seventy-five postterm fetuses underwent antepartum testing [non-stress test (NST); umbilical artery Doppler velocimetry (UAD); and Amniotic flUid index (AFI)) and M-mode echocardiography in which the right and left ventricular dimensions (RVID, LVID), the biventncular outer dimension (BVOD), and the RVID/LVID were measured. Each fetus was examined for the presence or absence of a pericardlal effusion (PE). Fetal distress was defined as abnormal intrapartum heart rate tracings associated with physician Intervention (02 administration, fetal scalp sampling, emergent delivery) Emergent delivery was defined as cesarean section or Instrumented vaginal delivery for fetal distress. Group I (N=32) had no fetal distress In labor, Group II (N =23) had fetal distress in labor not requiring emergent delivery, and Group III had fetal distress In labor requiring emergent delivery Comparing Groups I with Groups II and III demonstrated the NST and UAD not to predict intrapartum fetal distress or emergent delivery. However, there were significant differences between Groups I and II for RVID, RVID/LVID, and PE. There were significant differences between Groups I and III for the above as well as LVID, BVOD and AFI Linear logistic regression analYSIS (Groups I, II, III), identified RVID/LVID, LVID and PE as significant variables for predicting fetal distress In labor BVOD and AFI were predictive for fetal distress associated with emergent delivery The results of the study suggest that in fetuses who develop fetal distress in labor (Group II. III). there initially is dilatation of the right ventricle which may be aSSOCiated with a pericardlal effusion, followed by dilatation of the left ventricle. Cardiomegaly (BVOD) and an abnormal AFI are late changes but predlcitlve of fetal distress requiring emergent delivery
427
CORRELATION OF THE AMNIOTIC FLUID INDEX AND THE NON-STRESS TEST IN THE PRE TERM PREMATURE RUPTURED PATIENT JA Harding, ON Jackson, OF Lewis, CA Major, MP Nageotte, T Asrat University of California, Irvine, Long Beach MemoriaL Medical Center The amniotic fluid index (AFI) has been investigated in the preterm premature ruptured membranes (PPROM) patient and felt to have a potential association with latency period and outcome. 50 patients were prospectively collected from 1989 to 1990 with PPROM and followed expectantly with daily one hour Non-Stress Tests (NST) and blinded daily AFI exam. A total of 422 AFI values were obtained and compared to daily uterine activity and presence of decelerations on the NST prior to the actual onset of labor_ The average AFI was 5_9 + 2_1 cm (Range 1_3 to 16_0) and the daily relative rate of change in AF I was 0 _1 !. _5 cm/day (Range 0-20)_ Nonlaboring uterine activity was not found to have a statistically significant correlation with the daily alteration in the AFI regardless of the fetal position, gestational age or parity (p=.11). A slightly lower AFI (5.3!. 1.7 cm vs. 6.2!. 2.2 cm) was associated with a statistically significant increase in fetal decelerations (p<.001). However, this difference is beyond the standard error of the AFI measurement. We conclude that in the PPROM patient the AFI is a variable quantity on a daily basis, nonlaboring uterine activity does not alter the AFI value signifIcantly, and subtle AFI variations are associated with fetal heart rate deceleration patterns. The daily NST provldes a more sensitive marker for development of clinically s;gniflcant changes in fluid volumes than the daily AFI in the PPROM patient and should remain a mainstay in the expectant management of these patients.
,J.ltlll.ln
19~1
Am J Obstet (;, newl
428 DELAYED MORBIDITY WITH ABNORMAL NONSTRESS
x TESTS. '!1. Blessed , and S Bottoms. Wayne State University, Hutzel Hospital, Detroit, MI. An abnormal (nonreactive or suspicious) nonstress test (NST) is usually further evaluated with biophysical profile, contraction stress test, or repeat NST. If these are normal, the NST is often considered falsely abnormal. To evaluate this interpretation, we studied 644 pregnancies followed with NST's, using only results occurring at least 7 days before delivery. Of these, 40 had at least one abnormal NST (ANST), but whose pregnancy was allowed to continue for at least 7 days based on follow-up testing. This group was compared to the 604 patients with all normal NST's (NNST). Gestational age at delivery (GA-DEL), birth weight, and a morbidity score (M-SCORE) based on meconium, cesarean delivery, low Apgar score, and NICU admission were analyzed with ANOVA, controlling for gestational age at NST (GA-NST), and using only one NST per pregnancy. GA-DEL GA-NST NNST ANST 30-31 37.8 36.8 32-33 38.4 37.4 34-35 38.9 37.8 36-37 39.5 38.9 38-39 40.3 39.7 40-41 41.6 41.0
BIRTHWEIGHT NNST ANST 3380 2620 3150 2990 3200 3110 3320 2950 3410 3850 3670 2990
M-SCORE NNST ANST 0.49 1.55 0.01 0.49 -0.10 0.03 -0.12 0.60 -0.04 0.57 -0.27 2.21
Patients with an abnormal NST deliver earlier (p
429 NST
-EXPERT: AN "INTELLIGENT" APPROACH TO THE NONS TRESS TEST (NST). L. Devoe, A. AlonsO. V. Moret~E. Ramos:B. Banias~ D. Sherline, J. Searle~Depts of OBGYN and Biomedical Engineering. Medical College of Georgia, Augusta, GA. We have developed an expert system, NST EXPERT, in IQ LISP, to aid evaluation and utilization of the NST. It uses selected demographic data and risk factors to assess significance of NST results, suggest further management and predict infant outcome (risks of death, fetal distress, 5-Apgar < 7 or acidosis). Prospective system validation used 177 consecutive tested high risk pregnancies; 4 perinatologists and NST-EXPERT assessed each case independently. Ranges of agreement among the perinatologists and those between NSTEXPERT and each perinatologist were, respectively, for NST evaluation: 80%-94% and 80%-93% ; for clinical management: 73%-93% and 80%-94%; for outcome predicted: 80%-100% and 83%-93%. The agreement between all outcomes predicted and obtained was 80%87% for perinatologists and 85% for NST-EXPERT; for bad outcomes predicted and obtained, 28%-48% for perinatologists and 88% for NST-EXPERT. CONCLUSION: An expert system has been created that appears to perform contextual analysis of the NST, to suggest management schemes and obtain prognoses at the level of a clinician.