British Journal of Obstetrics and Gynaecology July 1979. Vol. 86. pp 533-539
NORMAL AND ABNORMAL ANTENATAL ULTRASONIC CARDIOGRAPHIC PATTERNS BY
H. MERKUR*, Registrar in Obstetrics and Gynaecology Royal Shrewsbury Hospital, Shrewsbury, U.K.
Summary Data is presented from 1019 antenatal ultrasonic cardiographs performed on 391 patients ; uterine contractions were not monitored concurrently with the fetal heart rate (FHR). No fetal deaths in utero or preterminal FHR patterns were seen within 24 hours of a normal trace. A comprehensive classification of FHR patterns is presented.
STRESSED and non-stressed antenatal cardiotocographs are now accepted methods of monitoring fetal well-being. The proponents of non-stressed cardiotocography come mainly from Europe and Great Britain (Kubli et al, 1977; Visser and Huisjes, 1977; Flynn and Kelly, 1977) whereas American authors have made a strong case for the oxytocin challenge test (Freeman, 1975; Freeman et al, 1976; Farahani et al, 1976; Garite et al, 1978). Correct interpretation of normal and abnormal fetal heart rate (FHR) patterns is of vital importance and a number of classifications and scoring systems have been devised (Rochard et al, 1976; Kubli et al, 1977; Visser and Huisjes, 1977; Pearson and Weaver, 1978). Just as electronic intrapartum monitoring can virtually eradicate intrapartum stillbirths (Beard, 1977), advocates of antenatal cardiotocography believe that many fetal deaths in utero can also be avoided. This study illustrates that the correct interpretation of antenatal FHR patterns provides enough information to manage most pregnancies which are at risk.
PATIENTS AND METHODS Three hundred and ninety one at-risk antenatal inpatients provided 1019 ultrasonic cardiographic traces for analysis. The study extended from March 1978 to January 1979. Recordings were made using Sonicaid FM2 and FM3 monitors at a paper speed of 1 cm/minute. The patient lay comfortably in her bed; no emphasis was put on exact positioning, unless the patient was symptomatically affected by supine hypotension or if an abnormal-looking trace was obtained in which case the patient was placed in the lateral recumbent position. Traces were recorded for at least 20 minutes and only accepted for analysis if technically adequate. If there were doubts as to the normality of the record obtained, it was extended to 40 minutes or more, or else repeated within a few hours. The uterine contractions were not monitored concurrently. The classification of the FHR patterns is shown in Table 1. Some of the patterns were adapted from other workers (Emmen et al, 1975; Rochard et al, 1976; Visser and Huisjes, 1977; Trimbos and Keirse, 1977; Wheeler and Murrills, 1978) and others were from the author’s observations. Apart from clinical findings, other methods used for monitoring fetal welfare included a
* Present address: 28 Tunstall Avenue, Kensington 2033, N.S.W., Australia. 533
534
MERKUR
fetal movement chart (Cardiff count-to-ten chart; Pearson and Weaver, 1976), serum human placental lactogen estimation, ultrasound B-scanning and amniocentesis for amniotic fluid palmitate levels.
RESULTS The distribution of the various patterns is shown in Table I; 995 traces (97.6 per cent) were normal. There were 24 abnormal traces TABLE I Fetal heart rate pattern Pattern Normal Normal
Description
Baseline FHR 120-160 bpm Baseline variability 5-50 bpm Large Baseline FHR 120-160 bpm swings Baseline variability >50 bpm Persistent Baseline FHR 160 bpm or tachycardia greater Baseline variability >5 bpm Rest-activity Baseline FHR 120-160 bpm Baseline variability < 10 bpm cycle for at least 15-20 minutes, reverting to other normal patterns Non-repetitive Baseline FHR 120-160 bpm deceleration Baseline variability >5 bpm One large deceleration >50 bpm Abnormal Preterminal
No.
618 255
TABLE I1 Primary indicationfor antenatal cardiograph
60
Indication for testing 58
4
Type A Flat trace with loss of baseline variability5:< bpm, associated with recurrent shallow decelerations 16 Type €3 Recurrent large declerations >50 bpm Flat Flat trace with loss of baseline 7 variability < 5 bpm, no decelerations Sinusoidal Baseline FHR 120-160 bpm 1 Loss of baseline variability < 5 bprn Sinusoidal pattern-frequency 2-5 per minute -amplitude 5-10 bpm -_______ Total 1019 FHR = fetal heart rate bpm = beats per minute
(2.4 per cent): 16 preterminal, 7 flat and 1 sinusoidal. Two types of preterminal pattern were seen : one with very small decelerations and the other with deep wide decelerations. The primary indications for performing the test are shown in Table 11. Of the 391 patients, two intrauterine fetal deaths occurred before the onset of labour in patients with a preterminal pattern that was not acted upon (patients 1 and 362, Table V). The time interval from the last cardiograph to the day of spontaneous labour, elective induction or elective Caesarean section is shown in Table 111. No fetal deaths in utero were seen within seven days of a normal trace. Three hundred and seventy four patients had normal traces only, leaving 17 patients with one or more abnormal traces; of the 374 ‘normals’ (386
No.
Hypertensive disorders Uncertain dates and postmaturity Antepartum haemorrhage Low serum human placental lactogen (less than 5th centile) Suspected fetal growth retardation Twin pregnancy Anaemia (haemoglobin less than 10 g/dl) Diabetes Other
29 21 11 9 9 112
Total
391
102 66 32
TABLEI11 Time from last cardiograph to delivery Interval between last cardiograph and delivery (days) 0
1 2 3 4 5 6 7 >7
Unrecorded Total
No. 23 94 63 33 17 13 15 15 115 3 391
Gestational diabetes Hydramnios, previous stillbirth Hypertension, unknown dates Severe pre-eclampsia, placenta praevia, transverse lie Two previous LSCS, unknown dates Unstable lie Ruptured membranes 38 weeks Threatened premature labour APH APH Hypertension, uncertain dates APH, unstable lie
88 134 178 188
--
285 303 331 334 376 3 80 391
Tension pneumothorax immediately-did well Did well Multiple abnormalities, died Did well Did well
38 38
36
-
2990 3790 2800 2980 3310 2800 3510 2760 850 2600 2490 2760 2600
LSCS for no progress LSCS for acute fetal distress LSCS for no progress Elective LSCS Elective LSCS LSCS for acute fetal distress LSCS for acute fetal distress SVD SVD SVD SVD Elective LSCS
39
28 34 36 -
40
39
-
SVD = spontaneous vertex delivery FGR = fetal growth retardation
Did well Did well Did well Did well Did well Did well Did well
Did well
Died day 8, septicaemia
39
2170
40
Did well
39
2630
Progress of baby
Breech LSCS for delay in second stage Breech LSCS for acute fetal distress LSCS for acute fetal distress
Apgar scores at 1 and 5 minutes
Gestation (weeks)
Birth weight (g)
Delivery
LSCS = lower segment Caesarean Section APH = antepartum haemorrhage
Hypertension
68
205
Hypertension, FGR
Complications
23
-Patient No. -2 APH
TABLE IV Normal antenatal cardiographsfollowed by delivery of an infant with afive-minute Apgar score of less than 7
-
ul
w
ul
aE
U
38 30
Hypertension, FGR
Low HPL, FGR, previous TUD
250
362
-
LSCS = lower segment Caesarean section FGR = fetal growth retardation APH = antepartum haemorrhage
12
2
37
Severe rhesus incompatibility
215
1
Yellow
Clear
2640
1930
2650
~
< 5th
< 5th
>loth
< 5th
< 5th
< 5th
10th >95th
< 5th
< 5th
(centile)
Elective LSCS. Apgar score 3 and 6, survived Elective LSCS, survived Emergency LSCS intrapartum stillbirth, grossly abnormal baby Vaginal delivery, intrapartum asphyxia. Apgar score 0 and 2, NND at 12 hours Emergency LSCS (fetal bradycardia following amniotomy). Apgar score 9 and 10, survived Emergency LSCS (fetal bradycardia following amniotomy). Apgar score 7 and 9. Cleft palate, micrognathia, survived Elective LSCS, Apgar score 5 and 8, cord haemoglobin 5.8 g/dl N N D at 12 hours (following exchange transfusion) Elective LSCS, Apgar score 4 and 7, survived Vaginal delivery, IUD
Vaginal delivery, IUD
Comments
HPL = human placental lactogen IUD = intrauterine fetal death NND = neonatal death
820
Meconium
2
2
38
FGR
196
Clear
Meconium 1870
15
1
1
40
Falling HPL
177
~
72
1
39
Low HPL, FGR
55
Oligohydramnios 1550 Meconium 1340 Clear 2800
Meconium 1750
20 12
2 2
32 28
Hypertension, methyl-dopa therapy, FGR Placenta praevia, recurrent APH
30 32
(8)
Birth weight
Meconium 1280
Amniotic fluid
12
24
1
34
8
2
36
2
1
34
Complications
Gestational age (weeks)
Interval between No. of first abnormal pretrace and terminal delivery or fetal traces death (hours)
Moderate to severe pre-eclampsia, asthmatic Hypertension, methyl-dopa therapy
Patient No.
--
TABLE V Clinical features of patients with preterminal cardiograph pattern
s
s
fl
w
Q\
w
vl
38
41 week gestation
Hypertension, FGR
Hypertension
248
250
270
APH = antepartum haemorrhage NND = neonatal death
41
Severe pre-eclampsia, high dose phenobarbitone
221
38
35
1
2
1
1
1
37
Severe rhesus incompatibility
21 5
1
38
Anaemia, recurrent APH, poor obs. history, valium sedation
Complications
Gestational age (weeks)
176
Patient No.
~~
Yellow
72
12
12
72
4190
1530
2640
3500
Clear
Elective LSCS, Apgar scores I and 9, survived
< 5th
>95th
4 t h
Amniotomy, vaginal delivery. Apgar scores 9 and 10, survived
Elective LSCS, Apgar scores 4 and 7,survived
Amniotomy, vaginal delivery. Apgar score 9 and 10, survived
Elective LSCS. Apgar scores 5 and 8, cord haemoglobin 5.8/dl NND a t 12 hours
> 10th
>90th
Elective LSCS, Apgar scores 8 and 10, survived
NORMAL AND ABNORMAL ANTENATAL ULTRASONIC CARDIOGRAPHIC PATTERNS BY
H. MERKUR*, Registrar in Obstetrics and Gynaecology Royal Shrewsbury Hospital, Shrewsbury, U.K.
Summary Data is presented from 1019 antenatal ultrasonic cardiographs performed on 391 patients ; uterine contractions were not monitored concurrently with the fetal heart rate (FHR). No fetal deaths in utero or preterminal FHR patterns were seen within 24 hours of a normal trace. A comprehensive classification of FHR patterns is presented.
STRESSED and non-stressed antenatal cardiotocographs are now accepted methods of monitoring fetal well-being. The proponents of non-stressed cardiotocography come mainly from Europe and Great Britain (Kubli et al, 1977; Visser and Huisjes, 1977; Flynn and Kelly, 1977) whereas American authors have made a strong case for the oxytocin challenge test (Freeman, 1975; Freeman et al, 1976; Farahani et al, 1976; Garite et al, 1978). Correct interpretation of normal and abnormal fetal heart rate (FHR) patterns is of vital importance and a number of classifications and scoring systems have been devised (Rochard et al, 1976; Kubli et al, 1977; Visser and Huisjes, 1977; Pearson and Weaver, 1978). Just as electronic intrapartum monitoring can virtually eradicate intrapartum stillbirths (Beard, 1977), advocates of antenatal cardiotocography believe that many fetal deaths in utero can also be avoided. This study illustrates that the correct interpretation of antenatal FHR patterns provides enough information to manage most pregnancies which are at risk.
PATIENTS AND METHODS Three hundred and ninety one at-risk antenatal inpatients provided 1019 ultrasonic cardiographic traces for analysis. The study extended from March 1978 to January 1979. Recordings were made using Sonicaid FM2 and FM3 monitors at a paper speed of 1 cm/minute. The patient lay comfortably in her bed; no emphasis was put on exact positioning, unless the patient was symptomatically affected by supine hypotension or if an abnormal-looking trace was obtained in which case the patient was placed in the lateral recumbent position. Traces were recorded for at least 20 minutes and only accepted for analysis if technically adequate. If there were doubts as to the normality of the record obtained, it was extended to 40 minutes or more, or else repeated within a few hours. The uterine contractions were not monitored concurrently. The classification of the FHR patterns is shown in Table 1. Some of the patterns were adapted from other workers (Emmen et al, 1975; Rochard et al, 1976; Visser and Huisjes, 1977; Trimbos and Keirse, 1977; Wheeler and Murrills, 1978) and others were from the author’s observations. Apart from clinical findings, other methods used for monitoring fetal welfare included a
* Present address: 28 Tunstall Avenue, Kensington 2033, N.S.W., Australia. 533
534
MERKUR
fetal movement chart (Cardiff count-to-ten chart; Pearson and Weaver, 1976), serum human placental lactogen estimation, ultrasound B-scanning and amniocentesis for amniotic fluid palmitate levels.
RESULTS The distribution of the various patterns is shown in Table I; 995 traces (97.6 per cent) were normal. There were 24 abnormal traces TABLE I Fetal heart rate pattern Pattern Normal Normal
Description
Baseline FHR 120-160 bpm Baseline variability 5-50 bpm Large Baseline FHR 120-160 bpm swings Baseline variability >50 bpm Persistent Baseline FHR 160 bpm or tachycardia greater Baseline variability >5 bpm Rest-activity Baseline FHR 120-160 bpm Baseline variability < 10 bpm cycle for at least 15-20 minutes, reverting to other normal patterns Non-repetitive Baseline FHR 120-160 bpm deceleration Baseline variability >5 bpm One large deceleration >50 bpm Abnormal Preterminal
No.
618 255
TABLE I1 Primary indicationfor antenatal cardiograph
60
Indication for testing 58
4
Type A Flat trace with loss of baseline variability5:< bpm, associated with recurrent shallow decelerations 16 Type €3 Recurrent large declerations >50 bpm Flat Flat trace with loss of baseline 7 variability < 5 bpm, no decelerations Sinusoidal Baseline FHR 120-160 bpm 1 Loss of baseline variability < 5 bprn Sinusoidal pattern-frequency 2-5 per minute -amplitude 5-10 bpm -_______ Total 1019 FHR = fetal heart rate bpm = beats per minute
(2.4 per cent): 16 preterminal, 7 flat and 1 sinusoidal. Two types of preterminal pattern were seen : one with very small decelerations and the other with deep wide decelerations. The primary indications for performing the test are shown in Table 11. Of the 391 patients, two intrauterine fetal deaths occurred before the onset of labour in patients with a preterminal pattern that was not acted upon (patients 1 and 362, Table V). The time interval from the last cardiograph to the day of spontaneous labour, elective induction or elective Caesarean section is shown in Table 111. No fetal deaths in utero were seen within seven days of a normal trace. Three hundred and seventy four patients had normal traces only, leaving 17 patients with one or more abnormal traces; of the 374 ‘normals’ (386
No.
Hypertensive disorders Uncertain dates and postmaturity Antepartum haemorrhage Low serum human placental lactogen (less than 5th centile) Suspected fetal growth retardation Twin pregnancy Anaemia (haemoglobin less than 10 g/dl) Diabetes Other
29 21 11 9 9 112
Total
391
102 66 32
TABLEI11 Time from last cardiograph to delivery Interval between last cardiograph and delivery (days) 0
1 2 3 4 5 6 7 >7
Unrecorded Total
No. 23 94 63 33 17 13 15 15 115 3 391
Gestational diabetes Hydramnios, previous stillbirth Hypertension, unknown dates Severe pre-eclampsia, placenta praevia, transverse lie Two previous LSCS, unknown dates Unstable lie Ruptured membranes 38 weeks Threatened premature labour APH APH Hypertension, uncertain dates APH, unstable lie
88 134 178 188
--
285 303 331 334 376 3 80 391
Tension pneumothorax immediately-did well Did well Multiple abnormalities, died Did well Did well
38 38
36
-
2990 3790 2800 2980 3310 2800 3510 2760 850 2600 2490 2760 2600
LSCS for no progress LSCS for acute fetal distress LSCS for no progress Elective LSCS Elective LSCS LSCS for acute fetal distress LSCS for acute fetal distress SVD SVD SVD SVD Elective LSCS
39
28 34 36 -
40
39
-
SVD = spontaneous vertex delivery FGR = fetal growth retardation
Did well Did well Did well Did well Did well Did well Did well
Did well
Died day 8, septicaemia
39
2170
40
Did well
39
2630
Progress of baby
Breech LSCS for delay in second stage Breech LSCS for acute fetal distress LSCS for acute fetal distress
Apgar scores at 1 and 5 minutes
Gestation (weeks)
Birth weight (g)
Delivery
LSCS = lower segment Caesarean Section APH = antepartum haemorrhage
Hypertension
68
205
Hypertension, FGR
Complications
23
-Patient No. -2 APH
TABLE IV Normal antenatal cardiographsfollowed by delivery of an infant with afive-minute Apgar score of less than 7
-
ul
w
ul
aE
U
38 30
Hypertension, FGR
Low HPL, FGR, previous TUD
250
362
-
LSCS = lower segment Caesarean section FGR = fetal growth retardation APH = antepartum haemorrhage
12
2
37
Severe rhesus incompatibility
215
1
Yellow
Clear
2640
1930
2650
~
< 5th
< 5th
>loth
< 5th
< 5th
< 5th
10th >95th
< 5th
< 5th
(centile)
Elective LSCS. Apgar score 3 and 6, survived Elective LSCS, survived Emergency LSCS intrapartum stillbirth, grossly abnormal baby Vaginal delivery, intrapartum asphyxia. Apgar score 0 and 2, NND at 12 hours Emergency LSCS (fetal bradycardia following amniotomy). Apgar score 9 and 10, survived Emergency LSCS (fetal bradycardia following amniotomy). Apgar score 7 and 9. Cleft palate, micrognathia, survived Elective LSCS, Apgar score 5 and 8, cord haemoglobin 5.8 g/dl N N D at 12 hours (following exchange transfusion) Elective LSCS, Apgar score 4 and 7, survived Vaginal delivery, IUD
Vaginal delivery, IUD
Comments
HPL = human placental lactogen IUD = intrauterine fetal death NND = neonatal death
820
Meconium
2
2
38
FGR
196
Clear
Meconium 1870
15
1
1
40
Falling HPL
177
~
72
1
39
Low HPL, FGR
55
Oligohydramnios 1550 Meconium 1340 Clear 2800
Meconium 1750
20 12
2 2
32 28
Hypertension, methyl-dopa therapy, FGR Placenta praevia, recurrent APH
30 32
(8)
Birth weight
Meconium 1280
Amniotic fluid
12
24
1
34
8
2
36
2
1
34
Complications
Gestational age (weeks)
Interval between No. of first abnormal pretrace and terminal delivery or fetal traces death (hours)
Moderate to severe pre-eclampsia, asthmatic Hypertension, methyl-dopa therapy
Patient No.
--
TABLE V Clinical features of patients with preterminal cardiograph pattern
s
s
fl
w
Q\
w
vl
38
41 week gestation
Hypertension, FGR
Hypertension
248
250
270
APH = antepartum haemorrhage NND = neonatal death
41
Severe pre-eclampsia, high dose phenobarbitone
221
38
35
1
2
1
1
1
37
Severe rhesus incompatibility
21 5
1
38
Anaemia, recurrent APH, poor obs. history, valium sedation
Complications
Gestational age (weeks)
176
Patient No.
~~
Yellow
72
12
12
72
4190
1530
2640
3500
Clear
Elective LSCS, Apgar scores I and 9, survived
< 5th
>95th
4 t h
Amniotomy, vaginal delivery. Apgar scores 9 and 10, survived
Elective LSCS, Apgar scores 4 and 7,survived
Amniotomy, vaginal delivery. Apgar score 9 and 10, survived
Elective LSCS. Apgar scores 5 and 8, cord haemoglobin 5.8/dl NND a t 12 hours
> 10th
>90th
Elective LSCS, Apgar scores 8 and 10, survived
