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The use of Doppler umbilical artery waveforms in placental abruption; a report of two cases
European Journal of Obstetrics & Gynecology and Reproductive Biology, 38 (1990) 167-168 Elsevier
EUROBS
167
01027
The use of Doppler umbilical artery waveforms in placental abruption; a report of two cases N.M. Rafla Liverpool Maternity Hospital, Liverpool, U.K. Accepted
for publication
30 January
1990
Summary
In a prospective study, the predictive value of Doppler umbilical arterial velocimetry waveforms in detecting the fetus at risk was examined in ten patients with abruptio placenta. One patient suffered intra-uterine fetal death within 8 h of obtaining a normal reactive cardiotocograph and normal umbilical artery waveforms. In another patient with severe placental abruption, following 2500 ml of blood loss, the umbilical artery waveforms were normal. In this study, umbilical artery waveforms failed to predict fetal outcome in cases of placental abruption. Doppler;
Umbilical
waveform;
Abruption;
Fetal death
in utero
Patients and methods
Introduction
Abruptio placentae is a relatively common complication of pregnancy and its incidence is l/120 deliveries [2]. The present paper examines the predictive value of Doppler arterial velocimetry waveforms in abruptio placentae in differentiating the ‘fetus at risk’ which requires delivery from one which can be treated conservatively. Cardiotocography is widely used as a method of fetal assessment particularly in the management of placental abruption. Intra-uterine fetal death following normal reactive cardiotocographic tracing and normal Doppler studies has been reported previously in a term pregnancy [l], but this is the first report on a case of placental abruption.
Correspondence: N.M. Rafla, Senior Registrar, Department of Obstetrics and Gynecology, University College Hospital, Galway, Ireland.
0028-2243/90/%03.50
0 1990 Elsevier Science Publishers
In ten patients attending the Liverpool Maternity Hospital, placental abruption was diagnosed clinically on the basis of symptoms of abdominal pain, associated with vaginal bleeding, uterine irritability and the demonstration of retroplacental clot on ultrasound examination. The subsequent monitoring of the patients included the measurement of the blood pressure, pulse rate and fetal cardiotocography. All patients gave their informed verbal consent to the study. Umbilical artery velocimetry waveforms were obtained with a linear array scanning model, SAL50A Toshiba 3.5 MHz, connected to a pulse Doppler unit; model SDL-OlA Toshiba and a Al00 Hz thump filter. The S/D ratio was obtained by dividing the value of the systolic peak over the end diastolic value. The use of this ratio overcomes the obstacle of not knowing the range between the incident
B.V. (Biomedical
Division)
168
beam and the direction of the motion [3]. The Doppler ultrasound information was not available to the clinicians managing the patients. Results and Case reports The mean maternal age was 25 years (range 19-33), and the mean gestational age was 32 weeks (range 27-39 weeks). The mean vaginal blood loss was 536 ml (range 80-2000 ml) and the mean retroplacental clot was 260 ml (range 100-500 ml). Umbilical artery velocimetry waveforms in all the ten patients with placental abruption were normal and the mean S/D ratios were 2.5 (range 1.8-2.9). In two patients the findings were specially noteworthy: A 25-year-old multigravida, with a history of two previous premature labours and a midtrimester abortion at 22 weeks, was admitted to hospital with a history of mild placental abruption. Vaginal blood loss was estimated to be 80 ml and she suffered from mild abdominal pain and uterine irritability. Cardiotocography and the S/D ratio were normal. In view of fetal prematurity (27 weeks gestation) the problem was managed conservatively. Seven hours later the fetal heart rate remained regular. One hour later fetal death in utero occurred suddenly. A stillborn fetus (990 grams) was delivered. The retro-placental clot was 300 ml. The placenta was normal histologically and showed no evidence of infection. A 24-year-old patient who previously had had a full-term normal delivery was admitted with a history of fulminating pre-eclampsia followed by severe placental abruption at 39 weeks gestation. She was delivered of a live infant following emergency Cesarean section. A large retroplacental clot (500 g) was removed. The total blood loss was 2500 ml, and the S/D ratio was 2.5 immediately before delivery. The cardiotocograph was non-reactive.
Discussion
This is the first prospective study on the application of Doppler arterial velocimetry waveforms in placental abruption. In the ten cases presented, Doppler arterial velocimetry wave forms have not proved to be useful in discriminating between the fetus ‘at risk’ and the fetus for whom conservative management could be applied. Serious complications can occur with abruptio placentae and often prompt delivery may save the fetus and spare the mother further complications. However, in patients where bleeding is minimal and the cardiotocograph is satisfactory, conservative management is sometimes preferred. Regrettably, in the first patient described, in whom minimal bleeding occurred at 27 weeks gestation and the cardiotocograph was satisfactory, Doppler arterial velocimetry waveforms also were normal, but the fetus died in utero 8 h later. The Doppler results therefore were of poor predictive value even in the second patient described, who suffered a severe abruption, in the presence of a non-reactive cardiotocograph. A normal S/D ratio would be expected in abruptio placentae if there was no associated restriction to blood flow to the placenta. As the end diastolic values were normal in all ten patients examined it appears that partial separation did not cause increase in resistance to flow. At a time when many groups are examining Doppler blood flow as a surveillance method, it is important to emphasize that preliminary studies reveal that this procedure is not reliable in cases of abruption. References Erskine RI, Ritchie JW, Zaltz A et al. Failure of nonstress test and Doppler-assessed umbilical arterial blood flow to detect imminent intra-uterine death. Am J Obstet Gynecol 1986;154:1109-1110. Knab DR Abruptio placenta: an assessment of the time and method of delivery Obstet Gynecol 1978;52:625-629. Schulman H, Fleischer A, Stem, W et al. Umbilical velocity wave ratios in human pregnancy, American J Obstet Gyneco1 1984;148:985-990.
EUROBS
167
01027
The use of Doppler umbilical artery waveforms in placental abruption; a report of two cases N.M. Rafla Liverpool Maternity Hospital, Liverpool, U.K. Accepted
for publication
30 January
1990
Summary
In a prospective study, the predictive value of Doppler umbilical arterial velocimetry waveforms in detecting the fetus at risk was examined in ten patients with abruptio placenta. One patient suffered intra-uterine fetal death within 8 h of obtaining a normal reactive cardiotocograph and normal umbilical artery waveforms. In another patient with severe placental abruption, following 2500 ml of blood loss, the umbilical artery waveforms were normal. In this study, umbilical artery waveforms failed to predict fetal outcome in cases of placental abruption. Doppler;
Umbilical
waveform;
Abruption;
Fetal death
in utero
Patients and methods
Introduction
Abruptio placentae is a relatively common complication of pregnancy and its incidence is l/120 deliveries [2]. The present paper examines the predictive value of Doppler arterial velocimetry waveforms in abruptio placentae in differentiating the ‘fetus at risk’ which requires delivery from one which can be treated conservatively. Cardiotocography is widely used as a method of fetal assessment particularly in the management of placental abruption. Intra-uterine fetal death following normal reactive cardiotocographic tracing and normal Doppler studies has been reported previously in a term pregnancy [l], but this is the first report on a case of placental abruption.
Correspondence: N.M. Rafla, Senior Registrar, Department of Obstetrics and Gynecology, University College Hospital, Galway, Ireland.
0028-2243/90/%03.50
0 1990 Elsevier Science Publishers
In ten patients attending the Liverpool Maternity Hospital, placental abruption was diagnosed clinically on the basis of symptoms of abdominal pain, associated with vaginal bleeding, uterine irritability and the demonstration of retroplacental clot on ultrasound examination. The subsequent monitoring of the patients included the measurement of the blood pressure, pulse rate and fetal cardiotocography. All patients gave their informed verbal consent to the study. Umbilical artery velocimetry waveforms were obtained with a linear array scanning model, SAL50A Toshiba 3.5 MHz, connected to a pulse Doppler unit; model SDL-OlA Toshiba and a Al00 Hz thump filter. The S/D ratio was obtained by dividing the value of the systolic peak over the end diastolic value. The use of this ratio overcomes the obstacle of not knowing the range between the incident
B.V. (Biomedical
Division)
168
beam and the direction of the motion [3]. The Doppler ultrasound information was not available to the clinicians managing the patients. Results and Case reports The mean maternal age was 25 years (range 19-33), and the mean gestational age was 32 weeks (range 27-39 weeks). The mean vaginal blood loss was 536 ml (range 80-2000 ml) and the mean retroplacental clot was 260 ml (range 100-500 ml). Umbilical artery velocimetry waveforms in all the ten patients with placental abruption were normal and the mean S/D ratios were 2.5 (range 1.8-2.9). In two patients the findings were specially noteworthy: A 25-year-old multigravida, with a history of two previous premature labours and a midtrimester abortion at 22 weeks, was admitted to hospital with a history of mild placental abruption. Vaginal blood loss was estimated to be 80 ml and she suffered from mild abdominal pain and uterine irritability. Cardiotocography and the S/D ratio were normal. In view of fetal prematurity (27 weeks gestation) the problem was managed conservatively. Seven hours later the fetal heart rate remained regular. One hour later fetal death in utero occurred suddenly. A stillborn fetus (990 grams) was delivered. The retro-placental clot was 300 ml. The placenta was normal histologically and showed no evidence of infection. A 24-year-old patient who previously had had a full-term normal delivery was admitted with a history of fulminating pre-eclampsia followed by severe placental abruption at 39 weeks gestation. She was delivered of a live infant following emergency Cesarean section. A large retroplacental clot (500 g) was removed. The total blood loss was 2500 ml, and the S/D ratio was 2.5 immediately before delivery. The cardiotocograph was non-reactive.
Discussion
This is the first prospective study on the application of Doppler arterial velocimetry waveforms in placental abruption. In the ten cases presented, Doppler arterial velocimetry wave forms have not proved to be useful in discriminating between the fetus ‘at risk’ and the fetus for whom conservative management could be applied. Serious complications can occur with abruptio placentae and often prompt delivery may save the fetus and spare the mother further complications. However, in patients where bleeding is minimal and the cardiotocograph is satisfactory, conservative management is sometimes preferred. Regrettably, in the first patient described, in whom minimal bleeding occurred at 27 weeks gestation and the cardiotocograph was satisfactory, Doppler arterial velocimetry waveforms also were normal, but the fetus died in utero 8 h later. The Doppler results therefore were of poor predictive value even in the second patient described, who suffered a severe abruption, in the presence of a non-reactive cardiotocograph. A normal S/D ratio would be expected in abruptio placentae if there was no associated restriction to blood flow to the placenta. As the end diastolic values were normal in all ten patients examined it appears that partial separation did not cause increase in resistance to flow. At a time when many groups are examining Doppler blood flow as a surveillance method, it is important to emphasize that preliminary studies reveal that this procedure is not reliable in cases of abruption. References Erskine RI, Ritchie JW, Zaltz A et al. Failure of nonstress test and Doppler-assessed umbilical arterial blood flow to detect imminent intra-uterine death. Am J Obstet Gynecol 1986;154:1109-1110. Knab DR Abruptio placenta: an assessment of the time and method of delivery Obstet Gynecol 1978;52:625-629. Schulman H, Fleischer A, Stem, W et al. Umbilical velocity wave ratios in human pregnancy, American J Obstet Gyneco1 1984;148:985-990.