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A study of fetal acceleration tests
I
FETUS, PLACENTA, AND NEWBORN
A study of fetal acceleration tests WILLIAM JOHN
F. RAYBURN, L. DUHRING.
MARCIA Lextngton,
M.D. M.D.
DONALDSON,
R.N.
Kentucky
The fetal acceleration test (FAT) is a means of assessing uteroplacental integrity by observing fetal heart patterns while being stressed by fetal movement. Of 584 tests performed on high-risk obstetric patients, 176 were done within 1 week prior to delivery. Favorable antepartum FAT results correlated with unremarkable initial intrapartum fetal monitor tracings in 128 (97.7 per cent) of 131 cases and also favorable 5 minute Apgar scores (7 to 10) in 128 (97.7 per cent) of 131 cases. An inconclusive FAT correlated with an abnormal OCT or intrapartum monitor tracing in nine of 10 tracings. Two infants with previously abnormal or suspicious FAT, OCT, and intrapartum fetal heart tracings were stillborn. The FAT was also less time-consuming and had fewer complications. These results show the FAT to be an effective clinical test for managing high-risk pregnancies with possible placental insufficiency. (AM. J. OBSTET. GYNEWL. 132: 33, 1978.)
NEW and refined methods of ancepartum fetal monitoring, perinatal morbidity and deaths have diminished. The concept of monitoring fetal heart patterns has proved to be beneficial in assessing fetal well being, because it is an indirect measure of fetal and placental oxygen reserve or respiratory function when the fetus is stressed.’ Several authors*-“ have shown that the oxytocin challenge test (OCT) is a reliable clinical procedure for managing high-risk pregnancies with possible placental insufficiency. Recently, the fetal acceleration test (FAT) or determination (FAD) was proposed to be a similar yet easier antepartum exam.” Fetal heart patterns are observed from stress produced by fetal movement inWITH
From the Department of Obstetrics and Gymology, UniversiQ of Kentucky Medical Center. Recewed for publication Revised January Accepted February
November
7, 1978.
26, 1978. 15, 1978.
Reprznt requests: Dr. John L. Duhring, Department Obstetrics and Gynecology, University of Kentucky, Medical Center, Lexington, Kentucffy 40506. OOOZ-9378/78/01132-0033$00.30/O
0
1978
The
C. V. Mosby
of
Co.
stead of oxytocin-induced uterine contractions. Previously reported series have indicated that the FAT correlates well with the OCT.” The purpose of this study was to correlate the FAT performed within 1 week of delivery with the initial intrapartum fetal monitor tracing and the perinatal outcome.
Materials and methods From July, 1975, to June, 1977, 4,378 deliveries occurred at the University of Kentucky Medical Center. Of these patients 307 underwent 578 FAT’s, These were all performed in the Outpatient Department by the same registered nurse. Table I lists the primary indications. Of these, 171 patients had an FAT within 1 week prior to delivery. A Corometrics 101-B monitor was used. The fetal heart race and fetal movements were recorded indirectly by using an abdominal Doppler ultrasound and tocographic instrument. Patients were also asked to notify the examiner when the fetus moved. Results were inadequate if there were no fetal movements even by’ stimulation by abdominal compression or by ringing a bell. An OCT was then per33
34
Rayburn, Duhring, and Donaldson
Table
I. Primary
indications
Indication
Postdatism Diabetes rnellitus Class A Class B Class C Class D Chronic hypertension Pre-eclampsia Rh negative, sensitized Heart disease IUGR, suspected Third-trimester bleed Elderly patient History of stillborn Repeat cesarean section for previous distress Previous toxemia Sickle-cell anemia History of premature delivery Fetal tachycardia Hyperthyroid Emphysema Total tests
Table IL Correlation between lavorable F Hal :urcl intrapartum fetal monitoring during early active labot-
for FAT
No.
38 5 9 2
%
120 54
54 22 13 8 8 6 4 4 4 3 2 2 1 1
39 18
18 7 4 2.6 2.6 2 1.3 1.3 1.3 1
--.A 307
Favorable
Table III. Correlation OCT or intrapartum early active labor
Results During the 2 year period at the University of Kentucky Obstetrics Outpatient Clinic, 7 per cent of the general obstetrics population underwent fetal acceleration testing. Those patients chosen had one or several high-risk factors with postdatism (39 per cent), diabetes (18 per cent), and chronic hypertension (18 per cent)
labor
.\‘o.
Xeg. I’OS.
11’8 .3
between inconclusive FA I- and fetal monitoring during
F.4T
Inconclusive
Neg.
1 9
POS.
Table IV. Correlation score at 5 minutes
between .4pgar 7-10
FAT
Favorable Inconclusive *Stillborn
formed. A test was unsatisfactory if no fetal heart pattern was clearly discernible. Any fetal heart acceleration during any fetal movements over a 20 minute period was considered normal or positive; the test was inconclusive if no acceleration of the heart baseline occurred. For each favorable FAT, the initial intrapartum fetal monitor tracing was reviewed. Any inconclusive FAT was followed closely with either an OCT or intraparturn fetal monitor, usually that same day. An OCT was performed with the use of the technique of Ray et a1.2 and Freeman3 Intrapartum fetal monitoring was begun when the patient was admitted in active labor. The initial dilatation of the cervix ranged from 2 to 7 cm. Neonatal well-being was objectively assessed by 5 minute Apgar score results, which were used to identify infants with acute impairment of metabolic balance. Scores of 7 to 10 suggested favorable metabolic balance and 0 to 3 suggested a very impaired neonatal metabolic state.
Early
F.4T
128 8
FAT
and Apgar
score at 5 min. ‘F-6
o-3
3 0
0 C) c*
infants.
being the most common primary indications. An average of 1.88 tests was done on each of the 307 patients. A toal of 171 patients had the FAT within I week prior to delivery: 154 (88 per cent) of the results were favorable and 10 (5.8 per cent) were inconclusive. Seven inadequate tests were recorded. Fetal movement with acceleration of the heart rate was appreciated on the six repeated prior to delivery. There were three unsatisfactory tests: one patient was morbidly obese, one could not lie on her back, and in the third case. the fetal position did not permit adequate recording of the heart rate. Of the 171 patients, 142 (83 per rent) had inttaparturn fetal monitoring. The favorable FAT results c’orrclated with normal labor monitor tracings in 128 (97.7 per cent) of 131 cases (see .fable II). An inconclusive FAT correlated with an abnormal OCT or labor monitor tracing in nine of 10 cases (SW Table IlIj. Favorable FAT’s correlatccl with 3 minute hpgar scores of 7 to 10 in 128 (97.7 per cent) of 131 cases. Eight of 10 infants born with a previously abnormal FAT had 5 minute Apar scores of 7 to 10. The other two were stillborn infants, however, having an abnormal OCT and fetal distress on pitocin-augmented labor (see Table IV). Each stillborn infant was at term, with each mother having severe hypertension and requiring primary cesarean section for fetal distress. One patient was a 35year-old woman with no prenatal care .tt term with lris-
Volume Number
I32 1
tory of previous hypertension. The FAT revealed no acceleration pattern with occasional movement. During pitocin-augmented labor that same day, a late deceleration pattern was later followed with a loss of beat-tobeat variability. A primary cesarean section was done for fetal distress, with satisfactory fetal heart tones being heard preoperatively. The stillborn infant was found to have a cleft lip and palate, along with a single umbilical artery. The mother did well postoperatively yet would not permit an autopsy. The other patient was 16 years old at term, referred for management of severe pre-eclampsia. During ultrasongography at the initial clinical visit, there was noted to be polyhydramnios with fetal ascites and a very large placenta, and meconium-stained amniotic fluid was aspirated. The FAT revealed no accelerations, yet few fetal movements were present. The OCT was positive with two mild decelerations recorded. A primary cesarean section was performed the next day after failure to progress with late deceleration on pitocin-augmented labor. Again, a good fetal heart rate was appreciated shortly before the operation. The stillborn infant was noted to be hydropic, and the subsequent autopsy revealed anasarca and mild cardiac hypertrophy of unknotizn origin.
Comment The fetal acceleration test (FAT) has proved to be a reliable primary screening tool for monitoring fetal well being and placental oxygen reserve when stressed by fetal movement. These results support previous findings by Lee, Di Loreto, and Logrand.” Favorable FAT’s correlated well with the initial intrapartum fetal monitor tracings and a favorable prognosis for the newborn infant. Any inconclusive FAT was also reinforced by an abnormal OCT or intrapartum tracing. Three of 131 infants with favorable FAT’s later had suspicious early labor tracings. Such tracings either involved variable dscelerations followed by mild decelerations. Each improved or remained the same after
REFERENCES 1. Lee, C. Y., Di Loreto, P. C., and @Lane, J. M.: Obstet. Gynecol. 45: 142, 1975. 2. Ray, M., Freeman, R., Pine, S., et al.: AM. J. OBSTET. GYNECOL. 114: 1, 1972.
Fetal
acceleration
tests
35
oxygen administration and with lying on the left side. All delivered vaginally without major complication. Eight of 10 infants with previous inconclusive FAT’s had favorable (7 to 10) Apgar scores. Each of these eight FAT’s was performed for postdate reasons. Six of these infants were delivered vaginally with little cornplication, usually on that same day. The other t\\o required cesarean sections for fetal distress after late decelerations were appreciated. All eight infants did well in the immediate neonatal period, with only two being postmature. Three of 13 1 infants with prior favorable FAT’s had low Apgar scores (4 to 6). Two infants were delivered vaginally with late decelerations noted late in labor. Each had meconium aspiration requiring intubation. The other infant was delivered by primary cesarean section for prolapsed cord. All three required immediate care in the intensive-care neonatal nursery but were discharged in satisfactory condition during nursery but were discharged in satisfactory condition during a brief hospitalization. Serial urinary estriols were done on several patients. A correlation between these values and FAT results was not determined. No blood gas studies were performed. No 6 week follow-up examinations were done on any infants. The cost to the patient of each FAT was the same as each OCT, yet the FAT required an average of 45 minutes, whereas the OCT required more than 2 hours. In addition, the intravenous lines were occasionally difficult to start, and the infused pitocin often caused inadequate or too frequent uterine contractions. These results are promising, since such a test can be used as an alternative to the oxytocin challenge test. Being less time-consuming, with fewer complications, the FAT has many advantages over the OCT. We thank Dr. Emery Wilson, Department of Obstetrics and Gynecology, for assistance on this paper.
3. Freeman, R. K.: AM. J. OBSTET. GYNECOL. 121: 481, 1975. 4. Bhakthavathaslan, A., Mann, L. I., Tejani, N. A.. and Weiss, R. R.: Obstet. Gynecol. 48: 552. 1976. 5. Lee, C. Y., Di Loreto, P. C., and Logrand, B.: Obstet. Gynecol. 48: 19, 1976.
FETUS, PLACENTA, AND NEWBORN
A study of fetal acceleration tests WILLIAM JOHN
F. RAYBURN, L. DUHRING.
MARCIA Lextngton,
M.D. M.D.
DONALDSON,
R.N.
Kentucky
The fetal acceleration test (FAT) is a means of assessing uteroplacental integrity by observing fetal heart patterns while being stressed by fetal movement. Of 584 tests performed on high-risk obstetric patients, 176 were done within 1 week prior to delivery. Favorable antepartum FAT results correlated with unremarkable initial intrapartum fetal monitor tracings in 128 (97.7 per cent) of 131 cases and also favorable 5 minute Apgar scores (7 to 10) in 128 (97.7 per cent) of 131 cases. An inconclusive FAT correlated with an abnormal OCT or intrapartum monitor tracing in nine of 10 tracings. Two infants with previously abnormal or suspicious FAT, OCT, and intrapartum fetal heart tracings were stillborn. The FAT was also less time-consuming and had fewer complications. These results show the FAT to be an effective clinical test for managing high-risk pregnancies with possible placental insufficiency. (AM. J. OBSTET. GYNEWL. 132: 33, 1978.)
NEW and refined methods of ancepartum fetal monitoring, perinatal morbidity and deaths have diminished. The concept of monitoring fetal heart patterns has proved to be beneficial in assessing fetal well being, because it is an indirect measure of fetal and placental oxygen reserve or respiratory function when the fetus is stressed.’ Several authors*-“ have shown that the oxytocin challenge test (OCT) is a reliable clinical procedure for managing high-risk pregnancies with possible placental insufficiency. Recently, the fetal acceleration test (FAT) or determination (FAD) was proposed to be a similar yet easier antepartum exam.” Fetal heart patterns are observed from stress produced by fetal movement inWITH
From the Department of Obstetrics and Gymology, UniversiQ of Kentucky Medical Center. Recewed for publication Revised January Accepted February
November
7, 1978.
26, 1978. 15, 1978.
Reprznt requests: Dr. John L. Duhring, Department Obstetrics and Gynecology, University of Kentucky, Medical Center, Lexington, Kentucffy 40506. OOOZ-9378/78/01132-0033$00.30/O
0
1978
The
C. V. Mosby
of
Co.
stead of oxytocin-induced uterine contractions. Previously reported series have indicated that the FAT correlates well with the OCT.” The purpose of this study was to correlate the FAT performed within 1 week of delivery with the initial intrapartum fetal monitor tracing and the perinatal outcome.
Materials and methods From July, 1975, to June, 1977, 4,378 deliveries occurred at the University of Kentucky Medical Center. Of these patients 307 underwent 578 FAT’s, These were all performed in the Outpatient Department by the same registered nurse. Table I lists the primary indications. Of these, 171 patients had an FAT within 1 week prior to delivery. A Corometrics 101-B monitor was used. The fetal heart race and fetal movements were recorded indirectly by using an abdominal Doppler ultrasound and tocographic instrument. Patients were also asked to notify the examiner when the fetus moved. Results were inadequate if there were no fetal movements even by’ stimulation by abdominal compression or by ringing a bell. An OCT was then per33
34
Rayburn, Duhring, and Donaldson
Table
I. Primary
indications
Indication
Postdatism Diabetes rnellitus Class A Class B Class C Class D Chronic hypertension Pre-eclampsia Rh negative, sensitized Heart disease IUGR, suspected Third-trimester bleed Elderly patient History of stillborn Repeat cesarean section for previous distress Previous toxemia Sickle-cell anemia History of premature delivery Fetal tachycardia Hyperthyroid Emphysema Total tests
Table IL Correlation between lavorable F Hal :urcl intrapartum fetal monitoring during early active labot-
for FAT
No.
38 5 9 2
%
120 54
54 22 13 8 8 6 4 4 4 3 2 2 1 1
39 18
18 7 4 2.6 2.6 2 1.3 1.3 1.3 1
--.A 307
Favorable
Table III. Correlation OCT or intrapartum early active labor
Results During the 2 year period at the University of Kentucky Obstetrics Outpatient Clinic, 7 per cent of the general obstetrics population underwent fetal acceleration testing. Those patients chosen had one or several high-risk factors with postdatism (39 per cent), diabetes (18 per cent), and chronic hypertension (18 per cent)
labor
.\‘o.
Xeg. I’OS.
11’8 .3
between inconclusive FA I- and fetal monitoring during
F.4T
Inconclusive
Neg.
1 9
POS.
Table IV. Correlation score at 5 minutes
between .4pgar 7-10
FAT
Favorable Inconclusive *Stillborn
formed. A test was unsatisfactory if no fetal heart pattern was clearly discernible. Any fetal heart acceleration during any fetal movements over a 20 minute period was considered normal or positive; the test was inconclusive if no acceleration of the heart baseline occurred. For each favorable FAT, the initial intrapartum fetal monitor tracing was reviewed. Any inconclusive FAT was followed closely with either an OCT or intraparturn fetal monitor, usually that same day. An OCT was performed with the use of the technique of Ray et a1.2 and Freeman3 Intrapartum fetal monitoring was begun when the patient was admitted in active labor. The initial dilatation of the cervix ranged from 2 to 7 cm. Neonatal well-being was objectively assessed by 5 minute Apgar score results, which were used to identify infants with acute impairment of metabolic balance. Scores of 7 to 10 suggested favorable metabolic balance and 0 to 3 suggested a very impaired neonatal metabolic state.
Early
F.4T
128 8
FAT
and Apgar
score at 5 min. ‘F-6
o-3
3 0
0 C) c*
infants.
being the most common primary indications. An average of 1.88 tests was done on each of the 307 patients. A toal of 171 patients had the FAT within I week prior to delivery: 154 (88 per cent) of the results were favorable and 10 (5.8 per cent) were inconclusive. Seven inadequate tests were recorded. Fetal movement with acceleration of the heart rate was appreciated on the six repeated prior to delivery. There were three unsatisfactory tests: one patient was morbidly obese, one could not lie on her back, and in the third case. the fetal position did not permit adequate recording of the heart rate. Of the 171 patients, 142 (83 per rent) had inttaparturn fetal monitoring. The favorable FAT results c’orrclated with normal labor monitor tracings in 128 (97.7 per cent) of 131 cases (see .fable II). An inconclusive FAT correlated with an abnormal OCT or labor monitor tracing in nine of 10 cases (SW Table IlIj. Favorable FAT’s correlatccl with 3 minute hpgar scores of 7 to 10 in 128 (97.7 per cent) of 131 cases. Eight of 10 infants born with a previously abnormal FAT had 5 minute Apar scores of 7 to 10. The other two were stillborn infants, however, having an abnormal OCT and fetal distress on pitocin-augmented labor (see Table IV). Each stillborn infant was at term, with each mother having severe hypertension and requiring primary cesarean section for fetal distress. One patient was a 35year-old woman with no prenatal care .tt term with lris-
Volume Number
I32 1
tory of previous hypertension. The FAT revealed no acceleration pattern with occasional movement. During pitocin-augmented labor that same day, a late deceleration pattern was later followed with a loss of beat-tobeat variability. A primary cesarean section was done for fetal distress, with satisfactory fetal heart tones being heard preoperatively. The stillborn infant was found to have a cleft lip and palate, along with a single umbilical artery. The mother did well postoperatively yet would not permit an autopsy. The other patient was 16 years old at term, referred for management of severe pre-eclampsia. During ultrasongography at the initial clinical visit, there was noted to be polyhydramnios with fetal ascites and a very large placenta, and meconium-stained amniotic fluid was aspirated. The FAT revealed no accelerations, yet few fetal movements were present. The OCT was positive with two mild decelerations recorded. A primary cesarean section was performed the next day after failure to progress with late deceleration on pitocin-augmented labor. Again, a good fetal heart rate was appreciated shortly before the operation. The stillborn infant was noted to be hydropic, and the subsequent autopsy revealed anasarca and mild cardiac hypertrophy of unknotizn origin.
Comment The fetal acceleration test (FAT) has proved to be a reliable primary screening tool for monitoring fetal well being and placental oxygen reserve when stressed by fetal movement. These results support previous findings by Lee, Di Loreto, and Logrand.” Favorable FAT’s correlated well with the initial intrapartum fetal monitor tracings and a favorable prognosis for the newborn infant. Any inconclusive FAT was also reinforced by an abnormal OCT or intrapartum tracing. Three of 131 infants with favorable FAT’s later had suspicious early labor tracings. Such tracings either involved variable dscelerations followed by mild decelerations. Each improved or remained the same after
REFERENCES 1. Lee, C. Y., Di Loreto, P. C., and @Lane, J. M.: Obstet. Gynecol. 45: 142, 1975. 2. Ray, M., Freeman, R., Pine, S., et al.: AM. J. OBSTET. GYNECOL. 114: 1, 1972.
Fetal
acceleration
tests
35
oxygen administration and with lying on the left side. All delivered vaginally without major complication. Eight of 10 infants with previous inconclusive FAT’s had favorable (7 to 10) Apgar scores. Each of these eight FAT’s was performed for postdate reasons. Six of these infants were delivered vaginally with little cornplication, usually on that same day. The other t\\o required cesarean sections for fetal distress after late decelerations were appreciated. All eight infants did well in the immediate neonatal period, with only two being postmature. Three of 13 1 infants with prior favorable FAT’s had low Apgar scores (4 to 6). Two infants were delivered vaginally with late decelerations noted late in labor. Each had meconium aspiration requiring intubation. The other infant was delivered by primary cesarean section for prolapsed cord. All three required immediate care in the intensive-care neonatal nursery but were discharged in satisfactory condition during nursery but were discharged in satisfactory condition during a brief hospitalization. Serial urinary estriols were done on several patients. A correlation between these values and FAT results was not determined. No blood gas studies were performed. No 6 week follow-up examinations were done on any infants. The cost to the patient of each FAT was the same as each OCT, yet the FAT required an average of 45 minutes, whereas the OCT required more than 2 hours. In addition, the intravenous lines were occasionally difficult to start, and the infused pitocin often caused inadequate or too frequent uterine contractions. These results are promising, since such a test can be used as an alternative to the oxytocin challenge test. Being less time-consuming, with fewer complications, the FAT has many advantages over the OCT. We thank Dr. Emery Wilson, Department of Obstetrics and Gynecology, for assistance on this paper.
3. Freeman, R. K.: AM. J. OBSTET. GYNECOL. 121: 481, 1975. 4. Bhakthavathaslan, A., Mann, L. I., Tejani, N. A.. and Weiss, R. R.: Obstet. Gynecol. 48: 552. 1976. 5. Lee, C. Y., Di Loreto, P. C., and Logrand, B.: Obstet. Gynecol. 48: 19, 1976.