AMERICAN JOURNAL OF PERINATOLOGY/VOLUME 8, NUMBER 5 September 1991
SONOGRAPHIC VERIFICATION OF A NUCHAL CORD FOLLOWING A VIBRATORY ACOUSTIC STIMULATION-INDUCED SEVERE VARIABLE FETAL HEART RATE DECELERATION WITH EXPEDIENT ABDOMINAL DELIVERY David M. Sherer, M.D., Jacques S. Abramowicz, M.D., Bobbi Hearn-Stebbins, RDMS, James R. Woods, Jr., M.D.
ABSTRACT
Sadovsky et al1 recently described a case in which application of external vibratory acoustic stimulation produced severe prolonged fetal bradycardia. The infant had a nuchal cord at delivery. We present a case in which similar stimulation caused a severe variable deceleration of the fetal heart rate, which returned to the normal baseline. Sonographic examination performed following this event disclosed the clinically suspected nuchal cord and oligohydramnios and assisted subsequent clinical management. CASE REPORT
A 35-year-old white woman, gravida 4, para 0, was admitted to Strong Memorial Hospital, the regional perinatal center at 32 weeks' gestation because of mild preeclampsia. Her past obstetric history was remarkable for two fetal losses. Her first pregnancy was complicated by preeclampsia and fetal death in utero at 38 weeks' gestation. The second loss was at 23 weeks' gestation due to premature rupture of the membranes. Her current pregnancy
Downloaded by: Universite de Sherbrooke. Copyrighted material.
A case is presented in which external vibratory acoustic stimulation performed following a nonreactive nonstress test produced a severe variable deceleration of the fetal heart rate. A clinically suspected nuchal cord was confirmed by ultrasound. This rapid precise antepartum diagnosis of cord compression prevented untimely delay and led to immediate abdominal delivery of a nonacidotic, yethypoxic, infant. This report suggests care be taken when fetal vibratory acoustic stimulation is applied in cases of oligohydramnios and a known existing nuchal cord.
was uneventful until 33 weeks' gestation, at which time she presented complaining of decreased fetal movements. On physical examination, her blood pressure was 140/100 mmHg, heart rate 80 beats/min, and fundal height was 34 cm. She had mild pedal edema and active deep tendon reflexes. Laboratory tests were all normal, except for trace proteinuria. A nonstress test was reactive (Cardiograph Model 8040A, Hewlett Packard Co., Waltham, MA). Three days after admission, a nonreactive nonstress test was noted. External vibratory acoustic stimulation was performed with an electric larynx (Model 5B, Western Electric, New York, NY; audible sound 750 to 1000 Hz, vibrations between 110 and 200 Hz, output density 110 dB). This provoked vigorous fetal movements and was followed immediately by a severe variable deceleration that returned to normal after 2 minutes (Fig. 1). A decision was made to deliver the fetus. A sonographic examination (Aloka Co., Japan, Model 280SL, with a 5MHz sector transducer) revealed decreased amniotic fluid with a nuchal cord (Fig. 2). This prompted immediate transverse lower segment cesarean sec-
Department of Obstetrics and Gynecology, the Division of Obstetrics and Maternal-Fetal Medicine, the Perinatal Ultrasound Laboratory, Strong Memorial Hospital, The University of Rochester School of Medicine and Dentistry, Rochester, New York Reprint requests: Dr. Sherer, Department of Obstetrics and Gynecology, Division of Obstetrics and Maternal-Fetal Medicine, Box 668, Strong Memorial Hospital, The University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642 Copyright © 1991 by Thieme Medical Publishers, Inc., 381 Park Avenue South, New York, NY 10016. All rights reserved.
345
EXTERNAL VIBRATORY ^COUSTIQ STIMULATION
Figure 1. Severe variable deceleration following vibratory acoustic stimulation (black arrow). Paper speed, 3 cm/min.
tion, which was performed under epidural anesthesia. A 1480 gm male infant was delivered with a tight nuchal cord. Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. Arterial umbilical cord blood gases were: pH 7.28; oxygen tension, 10 mmHg; carbon dioxide tension, 60 mmHg; base excess, 0. The infant and mother did well. COMMENT
Sonographic diagnosis of a nuchal cord has been demonstrated as a helpful adjunct in intrapar-
STRONG HEMOPJfiL HOSPFTO'l
September 1991
tum management of labor with repetitive variable decelerations.23 Currently, not enough data involving prenatal diagnosis and clinical outcome of such cases are available. It is therefore very uncertain whether ultrasound diagnosis of a nuchal cord improves clinical management. The sonographic evidence of a nuchal cord per se is not an indication for cesarean delivery even if variable decelerations are present. Other factors should be considered (scalp sampling, fetal heart rate beat-to-beat variability, labor pattern, and anticipated time of delivery).2 The case presented supports the theory that vigorous fetal movements induced by the stimulation may aggravate preexisting cord compression, as suggested by Sadovsky et al.1 This is the second case reported (and we have personally seen three other cases) of fetal bradycardia induced by external vibratory acoustic stimulation in conjunction with cord compression. We would suggest therefore that until further data are obtained, this stimulation test be used in cases of known nuchal cords or severe oligohydramnios only when immediate operative delivery facilities are available.
REFERENCES Sherer DM, Menashe M, Sadovsky E: Severe fetal bradycardia caused by external vibratory acoustic stimulation. Am J Obstet Gynecol 159:334-335, 1988 Feinstein SJ, Lodeiro JG, Vintzileos AM, et al: Intrapartum ultrasound diagnosis of nuchal cord as a decisive factor in management. Am J Obstet Gynecol 153:308-309, 1985 Pelosi MA: Antepartum ultrasonic diagnosis of cord presentation. Am J Obstet Gynecol 162:599-600, 1990
STRONG HEHORIflL HOSPITflL m is c
«•
1
spr
^
"* 1 ' m
t
-
vert* vtx
Figure 2. A: Longitudinal ultrasound demonstrating transverse section of nuchal cord (arrow). Vtx: Fetal vertex; Sp: fetal spine. B: Transverse ultrasound demonstrating longitudinal view of the nuchal cord (arrow). Vert: Fetal cervical vertebral ossification centers.
346
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AMERICAN JOURNAL OF PERINATOLOGY/VOLUME 8, NUMBER 5
SONOGRAPHIC VERIFICATION OF A NUCHAL CORD FOLLOWING A VIBRATORY ACOUSTIC STIMULATION-INDUCED SEVERE VARIABLE FETAL HEART RATE DECELERATION WITH EXPEDIENT ABDOMINAL DELIVERY David M. Sherer, M.D., Jacques S. Abramowicz, M.D., Bobbi Hearn-Stebbins, RDMS, James R. Woods, Jr., M.D.
ABSTRACT
Sadovsky et al1 recently described a case in which application of external vibratory acoustic stimulation produced severe prolonged fetal bradycardia. The infant had a nuchal cord at delivery. We present a case in which similar stimulation caused a severe variable deceleration of the fetal heart rate, which returned to the normal baseline. Sonographic examination performed following this event disclosed the clinically suspected nuchal cord and oligohydramnios and assisted subsequent clinical management. CASE REPORT
A 35-year-old white woman, gravida 4, para 0, was admitted to Strong Memorial Hospital, the regional perinatal center at 32 weeks' gestation because of mild preeclampsia. Her past obstetric history was remarkable for two fetal losses. Her first pregnancy was complicated by preeclampsia and fetal death in utero at 38 weeks' gestation. The second loss was at 23 weeks' gestation due to premature rupture of the membranes. Her current pregnancy
Downloaded by: Universite de Sherbrooke. Copyrighted material.
A case is presented in which external vibratory acoustic stimulation performed following a nonreactive nonstress test produced a severe variable deceleration of the fetal heart rate. A clinically suspected nuchal cord was confirmed by ultrasound. This rapid precise antepartum diagnosis of cord compression prevented untimely delay and led to immediate abdominal delivery of a nonacidotic, yethypoxic, infant. This report suggests care be taken when fetal vibratory acoustic stimulation is applied in cases of oligohydramnios and a known existing nuchal cord.
was uneventful until 33 weeks' gestation, at which time she presented complaining of decreased fetal movements. On physical examination, her blood pressure was 140/100 mmHg, heart rate 80 beats/min, and fundal height was 34 cm. She had mild pedal edema and active deep tendon reflexes. Laboratory tests were all normal, except for trace proteinuria. A nonstress test was reactive (Cardiograph Model 8040A, Hewlett Packard Co., Waltham, MA). Three days after admission, a nonreactive nonstress test was noted. External vibratory acoustic stimulation was performed with an electric larynx (Model 5B, Western Electric, New York, NY; audible sound 750 to 1000 Hz, vibrations between 110 and 200 Hz, output density 110 dB). This provoked vigorous fetal movements and was followed immediately by a severe variable deceleration that returned to normal after 2 minutes (Fig. 1). A decision was made to deliver the fetus. A sonographic examination (Aloka Co., Japan, Model 280SL, with a 5MHz sector transducer) revealed decreased amniotic fluid with a nuchal cord (Fig. 2). This prompted immediate transverse lower segment cesarean sec-
Department of Obstetrics and Gynecology, the Division of Obstetrics and Maternal-Fetal Medicine, the Perinatal Ultrasound Laboratory, Strong Memorial Hospital, The University of Rochester School of Medicine and Dentistry, Rochester, New York Reprint requests: Dr. Sherer, Department of Obstetrics and Gynecology, Division of Obstetrics and Maternal-Fetal Medicine, Box 668, Strong Memorial Hospital, The University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642 Copyright © 1991 by Thieme Medical Publishers, Inc., 381 Park Avenue South, New York, NY 10016. All rights reserved.
345
EXTERNAL VIBRATORY ^COUSTIQ STIMULATION
Figure 1. Severe variable deceleration following vibratory acoustic stimulation (black arrow). Paper speed, 3 cm/min.
tion, which was performed under epidural anesthesia. A 1480 gm male infant was delivered with a tight nuchal cord. Apgar scores were 8 and 9 at 1 and 5 minutes, respectively. Arterial umbilical cord blood gases were: pH 7.28; oxygen tension, 10 mmHg; carbon dioxide tension, 60 mmHg; base excess, 0. The infant and mother did well. COMMENT
Sonographic diagnosis of a nuchal cord has been demonstrated as a helpful adjunct in intrapar-
STRONG HEMOPJfiL HOSPFTO'l
September 1991
tum management of labor with repetitive variable decelerations.23 Currently, not enough data involving prenatal diagnosis and clinical outcome of such cases are available. It is therefore very uncertain whether ultrasound diagnosis of a nuchal cord improves clinical management. The sonographic evidence of a nuchal cord per se is not an indication for cesarean delivery even if variable decelerations are present. Other factors should be considered (scalp sampling, fetal heart rate beat-to-beat variability, labor pattern, and anticipated time of delivery).2 The case presented supports the theory that vigorous fetal movements induced by the stimulation may aggravate preexisting cord compression, as suggested by Sadovsky et al.1 This is the second case reported (and we have personally seen three other cases) of fetal bradycardia induced by external vibratory acoustic stimulation in conjunction with cord compression. We would suggest therefore that until further data are obtained, this stimulation test be used in cases of known nuchal cords or severe oligohydramnios only when immediate operative delivery facilities are available.
REFERENCES Sherer DM, Menashe M, Sadovsky E: Severe fetal bradycardia caused by external vibratory acoustic stimulation. Am J Obstet Gynecol 159:334-335, 1988 Feinstein SJ, Lodeiro JG, Vintzileos AM, et al: Intrapartum ultrasound diagnosis of nuchal cord as a decisive factor in management. Am J Obstet Gynecol 153:308-309, 1985 Pelosi MA: Antepartum ultrasonic diagnosis of cord presentation. Am J Obstet Gynecol 162:599-600, 1990
STRONG HEHORIflL HOSPITflL m is c
«•
1
spr
^
"* 1 ' m
t
-
vert* vtx
Figure 2. A: Longitudinal ultrasound demonstrating transverse section of nuchal cord (arrow). Vtx: Fetal vertex; Sp: fetal spine. B: Transverse ultrasound demonstrating longitudinal view of the nuchal cord (arrow). Vert: Fetal cervical vertebral ossification centers.
346
Downloaded by: Universite de Sherbrooke. Copyrighted material.
AMERICAN JOURNAL OF PERINATOLOGY/VOLUME 8, NUMBER 5
