- Email: [email protected]
External cephalic version of the breech presentation under tocolysis
Bastide et al.
April, 1986
Am J Obstet Gynecol
indicate that obstetric intervention is both warranted and indicated. REFERENCES 1. Manning FA, Platt LD, Sipos L. Antepartum fetal evaluation: development of a fetal biophysical profile score. AM ] OBSTETGYNECOL 1980;136:787. 2. Haworth ]A, Pussey VA. The relationship between birth weight and gestational age for a Winnipeg hospital population. Can Med Assoc] 1961; 100:842. 3. Chamberlain PF, Manning FA, Morrison I, et al. Ultrasound evaluation of amniotic fluid. I. The relationship of marginal and decreased amniotic fluid volume to perinatal outcome. AM] OBSTET GYNECOL 1984; 150:245. 4. Chamberlain PF, Manning FA, Morrison I, et al. Circadian rhythm in bladder volume in the term human fetus. Obstet GynecoI1984;64:657.
5. Chamberlain PF, Cumming M, Torchia MG, et al. Ovine fetal urine production following maternal intravenous furosemide administration. AM] OBSTET GYNECOL 1985; 151 : 815-9. 6. Manning FA, Hill LM, Platt LD. Quantitative amniotic fluid volume determination by ultrasound: antepartum detection of intrauterine growth retardation. AM] OBSTET GyNECOL 1981;139:254. 7. Cohn HE, Sacks E], Heyman MA, et al. Cardiovascular responses to hypoxemia and acidemia in fetal lambs. AM] OBSTETGYNECOL 1974;120:817. 8. Wladimiroff ]W, Campbell S. Fetal urine production rates in normal and complicated pregnancies. Lancet 1974; 2: 151. 9. Druzin ML, Gratacos], Keegan KA, et al. Antepartum fetal heart rate testing. VII. The significance of fetal bradycardia. AM] OBSTETGYNECOL 1981;139:194.
External cephalic version of the breech presentation under tocolysis John C. Morrison, M.D., Ray E. Myatt, M.D., James N. Martin, Jr., M.D., G. Rodney Meeks, M.D., Rick W. Martin, M.D., Edsel T. Bucovaz, Ph.D., and Winfred L. Wiser, M.D. Jackson,
Mississippi
External cephalic version with tocolysis at or near ~erm has been advocated to avoid cesarean birth for breech presentation. In our institution this maneuver was successfully performed in 207 of 304 parturients without major complications, and a" but six had vertex presentation at delivery. The success of version was inversely correlated with gestational age but was not correlated with ease of version, number of attempts, or placental location. When this 3-year period was compared with the previous three years (1979 to 1981), there was a significant reduction in the number of breech presentations during labor, whereas the total delivery rate remained relatively constant over the 6-year period. It appears that in a carefully selected population, external version near term can be used safely to reduce the need for abdominal birth because of breech presentation. (AM J OBSTET GVNECOL 1986;154:900-3.)
Key words: Tocolysis, external cephalic version, breech presentation It is well known that vaginal delivery in a breech presentation involves a greater risk of perinatal mortality and morbidity than that in a cephalic presentation. 1 The increased damage in breech infants at term frequently appears to be the result of traumatic delivery in cases showing slight degrees of disproportion not easily predicted in advance by clinical or radiologic
From the Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Mississippi Medical Center. Supported in part by the Vicksburg Hospital Medical Foundation. Received for publication November 1, 1985; accepted December 24,
1985. Reprint requests: Dr. John C. Morrison, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of MississiPPi Medical Center, 2500 North State St., Jackson, MS
39216.
900
study.2 It has been suggested that cesarean birth should be employed more often in an effort to reduce neonatal damage at term with breech presentation, but this strategy increases maternal mortality and morbidity. Two management schemes to address this dilemma have evolved: one embraces routine abdominal delivery for breech presentation, whereas the other advocates scoring systems to select patients for "safe" vaginal delivery." 4 Both management techniques, however, result in an increased cesarean birth rate with its inherently high maternal morbidity rate, and neither attacks the primary problem of the breech presentation itself. Several authors have advocated early external cephalic version as a simple and safe method to reduce the incidence of breech presentation at term." 6 Unfortunately, the earlier the version attempt, the more
External cephalic version with tocolysis
Volume 154 Number 4
901
Table I. Presentation in labor after version Presentation Version attempt
No. of patients
Vertex
Successful Unsuccessful
207
201
97
o
likely the fetus is to return to the breech presentation, whereas the later the version, the less likely the attempt will succeed. 6 Further, some care providers believe that the procedure may pose excessive fetal risk in the form of placental separation, cord accident, or Rh sensitization. 5 To circumvent some of these problems, Saling and Muller-Holve proposed the practice of external cephalic version using f3-sympathomimetic tocolysis after 37 weeks' gestation. This method offers several potential advantages over early version: (1) spontaneous reversion to breech is uncommon, (2) if fetal distress occurs, the fetus is mature enough for immediate delivery, and (3) uterine relaxation should facilitate easier manipulation. More recently, others have corroborated those findings. 8 . 9 Reports on the use of tocolysis in a larger number of patients to access the potential complications to mother and fetus, as well as its impact on the mode of delivery, were not available in the literature. For that reason a study was undertaken in our institution. Material and methods
During a 3-year period (January, 1982, to December, 1984), 304 normal, "low-risk" patients with breech presentations at greater than 36 weeks' gestation were selected for attempted breech version and agreed to the study protocol, which had been approved by the Institutional Review Board of the University of Mississippi Medical Center. Details of the procedure, potential benefits and risks, and the safeguards to be employed were explained to the patient. The decision to perform the procedure was contingent on her understanding of the protocol. Patients were entered in the study after informed consent forms had been signed. Patients with the following conditions were excluded: (1) maternal cardiac disease, (2) hypertension, (3) premature rupture of the membranes, (4) intrauterine growth retardation, (5) previous uterine surgery, (6) multiple gestation, (7) placenta previa, and (8) oligohydramnios. Requirements for inclusion into the study included (1) gestation ~36 weeks, (2) breech presentation, (3) absence of any contraindication (exclusion criteria), (4) normal sonographic appearance of fetus, placenta, and amniotic fluid volume, and (5) a reactive nonstress test. The procedure was conducted in the labor and de-
I
Method of delivery Breech
Vaginal
6 97
182 37
I
Abdominal
25 60
livery area. All patients underwent a thorough realtime ultrasound B scanning examination, a nons tress test, and a pelvic examination. A normal real-time B scan was defined as follows: singleton fetus in the breech position; adequate fluid (at least a 1.0 em pocket of fluid); biparietal diameter >8.5 em but < 10.5 em and an absence of gross fetal anomalies; or placenta previa. Patients were placed in the lateral semirecumbent position with left uterine displacement. An intravenous line was initiated with a crystalloid solution. A nonstress test was performed, and after a reactive pattern was noted, ritodrine hydrochloride was infused at 0.1 mg/min for 15 minutes prior to and during the procedure. Maternal heart rate and blood pressure were continuously monitored, as was the fetal heart rate. Version was accomplished by the classic "forward roll" technique if the fetal spine and head were on the same side of the maternal midline. The "back flip" method of Saling and Muller-Holve was used if the initial method failed. A second examiner manipulated the opposite fetal pole or assisted by vaginal elevation of the breech. The procedure was interrupted if patient discomfort became severe or if fetal heart rate decelerations were noted. In many cases, multiple attempts at version were performed. Once the fetus was turned satisfactorily, the f3-sympathomimetic infusion was discontinued and the fetus was maintained in the new attitude until uterine tone returned. Real-time B scan was used to confirm version success. For Rh-negative, unsensitized patients, Rh immune globulin was administered following version. After the procedure, fetal heart rate monitoring was continued until a reactive nonstress test was noted. The following maternal, fetal, and newborn variables were tabulated: (1) ease of version, defined according to the amount of time required to complete the maneuver and the number of attempts (an easy version was completed within 1 minute, with one or two attempts; a moderately difficult version was between 1 and 5 minutes, with two to five attempts; and a difficult version required longer than 5 minutes, with more than five attempts); (2) discomfort during the procedure (patients were asked to describe the procedure as painless or as mildly, moderately, or severely uncomfortable); (3) maternal heart rate and blood pressure; (4) fetal heart rate and uterine activity during and following the version; (5) vaginal bleeding, timing of rupture of the
902
Morrison et al.
April, 1986 Am J Obstet Gynecol
Table II. Effect of gestational age in version Successful*
Unsuccessful
Table IV. Mode of delivery for singleton breech fetuses at term
Gestational age (wk)
n
37-39 40-43
179 28
I
%
n
73 45
64 33
I
1979-1981
% 27 55
*p < 0.001.
All deliveries Cesarean birth (breech) Vaginal delivery (breech) Total
Table III. Effect of placental location on version
Anterior (n Posterior (n Total (n
=
= 128) = 176)
304)
n
%
n
%
12,942 359 230
61 39
13,221 216 150
59 41
589
366*
*p < 0.001.
Unsuccessful Placentallocation*
1982-1984
Successful
n
83 124
45 52
207
97
I
% 46 54
*p < 0.3.
membranes, and onset of labor; (6) intrapartum presentation and route of delivery; and (7) evidence of morbidity during the neonatal period. The X' analysis was used to detect statistical differences, and a p value of <0.05 was considered significant.
Results Version was successful in 207 of 304 patients (68%). In all of the successful versions, the fetuses had vertex presentations during labor, except six that reverted spontaneously to breech; five of them were delivered by cesarean birth (Table I). A subseptate uterus and a partial placenta previa were found during a cesarean delivery in two of these five cases. The abdominal delivery rate among the subjects (201) with a vertex presentation was 10%, and in no case was the indication for cesarean birth thought to be associated with the version. Of the 97 futile attempts, all deliveries were breech births and 62% were operative births (Table I). Of the successful versions, the vast majority were deemed easy (167), whereas 31 were moderately difficult and nine were difficult. Of these 207 parturients, 66 patients reported the procedure to be painless, 118 noted mild discomfort, and 23 described the version to be moderately uncomfortable. No patients reported severe or intolerable pain. Among the unsuccessful group, severe pain was the reason to discontinue the procedure in 12 subjects, whereas the type of pain noted subjectively was equally distributed (none, mild, moderate) among the other 85 patients in this group. In none of the 304 patients did rupture of the membranes, vaginal bleeding, or onset of labor occur within 24 hours of the attempted version. In none of the cases did uterine rupture or catastrophic maternal-fetal events occur. Fetal heart rate abnormalities (tach ycar-
dia, bradycardia, change in baseline, variable decelerations) occurred in 18% of the subjects during or after the procedure, but all responded to conservative management (oxygen, change in position, fluid administration with observation). Fetal heart rate abnormalities were a reason to abort version attempts in only six patients and were not related to the number of attempts or the ease of version. In no case was emergency delivery necessary. Likewise, hypotension, tachycardia, or other maternal side effects of the tocolytic agent did not necessitate abandonment of the procedure in any of the 304 patients. The total time for the procedure from entry into the delivery area until discharge was 160 ± 43 minutes among the successful group and 180 ± 51 minutes in those with failed version attempts. A significant difference in version success rate was noted when gestational age at the time of version was compared (Table II). At gestatational ages of 37 to 39 weeks, 179 of 243 attempts (73%) were successful in comparison with 45% (28 of 61) at 40 to 43 weeks (p < 0.001). In contrast, no difference was apparent in version success rate when placental location was used as the discriminator (Table III). Version was unsuccessful in 45 of 128 patients (46%) with anterior placentation and in 52 of 176 patients (54%) with posterior placental placement (p = 0.3). Careful examination during labor and at delivery disclosed no increased incidence of maternal-fetal-neonatal abnormalities related to the procedure. No increase in meconium-stained fluid, abnormal intrapartum fetal heart rate tracings, low Apgar scores, or neonatal or placental trauma was noted among the total group in comparison with a like number of term infants whose mothers did not undergo an attempted version. In none of the Rh-negative parturients was sensitization noted at delivery.
Comment The data from this study and a review of the literature leave little doubt that external cephalic version near term will reduce the incidence of breech presentation in labor. Between 90% and 97% of successful versions can be expected to remain as vertex presen-
Volume 154 Number 4
tations until the onset of labor. SolO In addition, few breech fetuses spontaneously convert to the vertex presentation after 36 weeks' gestation. 6 In this study, 68% of the breech presentations were converted to vertex successfully, and all but six fetuses presented in this attitude; figures were similar to those in other series. 7 -9 The impact of breech version on the cesarean birth rate has not been well defined, primarily because of diverse strategies regarding the management of breech presentations at term and because of the lack of large numbers of patients in most studies. We have been challenged to reduce the number of abdominal deliveries. 1I In our study, only 10% of successful versions required cesarean section, in comparison with 60% of the failure group. As shown in Table IV, the number of breech deliveries during the study period was significantly reduced (p < 0.001) in comparison with the preceding 3 years, although the total delivery rate increased by 5.4%. The percentage of cesarean versus vaginal deliveries did not differ during both periods for patients with a breech presentation during labor. As a result, the abdominal delivery rate was reduced by this strategy. Obviously, the higher the cesarean birth rate for breech presentation at term in any institution, the greater will be the impact of a program of external versIOn. The most pertinent question, other than the success of this modality, involves the safety of the procedure. lo • 12 In this study, no intrauterine deaths or neonatal losses attributed to a cord accident or placental abruption occurred. Other studies offer similar results.s° 1O Strict insistence on a normal fetal heart rate pattern both before and after version, as well as a normal real-time B scan, identifies the potentially compromised fetus and/or placental unit. Careful intraprocedure monitoring allows repetitive manipulation in individual cases where fetal heart rate irregularities transiently occur.
External cephalic version with tocolysis
903
In conclusion, these data indicate that in the carefully monitored and selected patient population, external version, near term, of the breech presentation can safely increase the vertex attitude by the onset of labor. This strategy would appear to reduce the need for cesarean birth. Constant vigilance, however, is necessary during the procedure to ensure that one does not damage the fetus or the parturient. REFERENCES 1. Manzke H. Morbidity among infants born in breech presentation.] Perinat Med 1978;6:127-40. 2. Collea]V, Rabin SC, Weghorst GR, et al. The randomized management of term frank breech presentation: vaginal delivery versus cesarean section. AM] OBSTET GYNECOL 1978;131:186-95. 3. Main DM, Main EK, Maurer MM. Cesarean section versus vaginal delivery for the breech fetus weighing less than 1,500 grams. AM] OBSTET GYNECOL 1983;146:580-4. 4. Gimovsky ML, Wallace RL, Schifrin BS, et al. Randomized management of the nonfrank breech presentation at term: a preliminary report. AM ] OBSTET GYNECOL 1983;146:34-40. 5. Friedlander D. External cephalic version in the management of breech presentation. AM ] OBSTET GYNECOL 1966;95:906-13. 6. Ranney B. The gentle art of external cephalic version. AM] OBSTET GYNECOL 1973;116:239-51. 7. Saling E, Muller-Holve W. External cephalic version under tocolysis.] Perinat Med 1975;3: 115-22. 8. Van Dorsten ]P, Schifrin BS, Wallace RL. Randomized control trial of external cephalic version with tocolysis in late pregnancy. AM] OB5TET GYNECOL 1981; 141 :417-24. 9. Fall 0, Nilsson BA. External cephalic version in breech presentation under tocolysis. Obstet Gynecol 1979;53: 712-5. 10. Phelan, ]P, Stine LE, Mueller E, et al. Observations of fetal heart rate characteristics related to external cephalic version and tocolysis. AM ] OB5TET GYNECOL 1984; 149:658-61. 11. Gleicher N. Cesarean section rates in the United States: the short-term failure of the National Consensus Development Conference in 1980. ]AMA 1984;252:3273-6. 12. Berg D, Kunze U. Critical remarks on external cephalic version under tocolysis: report on a case of antepartum fetal death.] Perinat Med 1977;5:32-3.
April, 1986
Am J Obstet Gynecol
indicate that obstetric intervention is both warranted and indicated. REFERENCES 1. Manning FA, Platt LD, Sipos L. Antepartum fetal evaluation: development of a fetal biophysical profile score. AM ] OBSTETGYNECOL 1980;136:787. 2. Haworth ]A, Pussey VA. The relationship between birth weight and gestational age for a Winnipeg hospital population. Can Med Assoc] 1961; 100:842. 3. Chamberlain PF, Manning FA, Morrison I, et al. Ultrasound evaluation of amniotic fluid. I. The relationship of marginal and decreased amniotic fluid volume to perinatal outcome. AM] OBSTET GYNECOL 1984; 150:245. 4. Chamberlain PF, Manning FA, Morrison I, et al. Circadian rhythm in bladder volume in the term human fetus. Obstet GynecoI1984;64:657.
5. Chamberlain PF, Cumming M, Torchia MG, et al. Ovine fetal urine production following maternal intravenous furosemide administration. AM] OBSTET GYNECOL 1985; 151 : 815-9. 6. Manning FA, Hill LM, Platt LD. Quantitative amniotic fluid volume determination by ultrasound: antepartum detection of intrauterine growth retardation. AM] OBSTET GyNECOL 1981;139:254. 7. Cohn HE, Sacks E], Heyman MA, et al. Cardiovascular responses to hypoxemia and acidemia in fetal lambs. AM] OBSTETGYNECOL 1974;120:817. 8. Wladimiroff ]W, Campbell S. Fetal urine production rates in normal and complicated pregnancies. Lancet 1974; 2: 151. 9. Druzin ML, Gratacos], Keegan KA, et al. Antepartum fetal heart rate testing. VII. The significance of fetal bradycardia. AM] OBSTETGYNECOL 1981;139:194.
External cephalic version of the breech presentation under tocolysis John C. Morrison, M.D., Ray E. Myatt, M.D., James N. Martin, Jr., M.D., G. Rodney Meeks, M.D., Rick W. Martin, M.D., Edsel T. Bucovaz, Ph.D., and Winfred L. Wiser, M.D. Jackson,
Mississippi
External cephalic version with tocolysis at or near ~erm has been advocated to avoid cesarean birth for breech presentation. In our institution this maneuver was successfully performed in 207 of 304 parturients without major complications, and a" but six had vertex presentation at delivery. The success of version was inversely correlated with gestational age but was not correlated with ease of version, number of attempts, or placental location. When this 3-year period was compared with the previous three years (1979 to 1981), there was a significant reduction in the number of breech presentations during labor, whereas the total delivery rate remained relatively constant over the 6-year period. It appears that in a carefully selected population, external version near term can be used safely to reduce the need for abdominal birth because of breech presentation. (AM J OBSTET GVNECOL 1986;154:900-3.)
Key words: Tocolysis, external cephalic version, breech presentation It is well known that vaginal delivery in a breech presentation involves a greater risk of perinatal mortality and morbidity than that in a cephalic presentation. 1 The increased damage in breech infants at term frequently appears to be the result of traumatic delivery in cases showing slight degrees of disproportion not easily predicted in advance by clinical or radiologic
From the Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of Mississippi Medical Center. Supported in part by the Vicksburg Hospital Medical Foundation. Received for publication November 1, 1985; accepted December 24,
1985. Reprint requests: Dr. John C. Morrison, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, University of MississiPPi Medical Center, 2500 North State St., Jackson, MS
39216.
900
study.2 It has been suggested that cesarean birth should be employed more often in an effort to reduce neonatal damage at term with breech presentation, but this strategy increases maternal mortality and morbidity. Two management schemes to address this dilemma have evolved: one embraces routine abdominal delivery for breech presentation, whereas the other advocates scoring systems to select patients for "safe" vaginal delivery." 4 Both management techniques, however, result in an increased cesarean birth rate with its inherently high maternal morbidity rate, and neither attacks the primary problem of the breech presentation itself. Several authors have advocated early external cephalic version as a simple and safe method to reduce the incidence of breech presentation at term." 6 Unfortunately, the earlier the version attempt, the more
External cephalic version with tocolysis
Volume 154 Number 4
901
Table I. Presentation in labor after version Presentation Version attempt
No. of patients
Vertex
Successful Unsuccessful
207
201
97
o
likely the fetus is to return to the breech presentation, whereas the later the version, the less likely the attempt will succeed. 6 Further, some care providers believe that the procedure may pose excessive fetal risk in the form of placental separation, cord accident, or Rh sensitization. 5 To circumvent some of these problems, Saling and Muller-Holve proposed the practice of external cephalic version using f3-sympathomimetic tocolysis after 37 weeks' gestation. This method offers several potential advantages over early version: (1) spontaneous reversion to breech is uncommon, (2) if fetal distress occurs, the fetus is mature enough for immediate delivery, and (3) uterine relaxation should facilitate easier manipulation. More recently, others have corroborated those findings. 8 . 9 Reports on the use of tocolysis in a larger number of patients to access the potential complications to mother and fetus, as well as its impact on the mode of delivery, were not available in the literature. For that reason a study was undertaken in our institution. Material and methods
During a 3-year period (January, 1982, to December, 1984), 304 normal, "low-risk" patients with breech presentations at greater than 36 weeks' gestation were selected for attempted breech version and agreed to the study protocol, which had been approved by the Institutional Review Board of the University of Mississippi Medical Center. Details of the procedure, potential benefits and risks, and the safeguards to be employed were explained to the patient. The decision to perform the procedure was contingent on her understanding of the protocol. Patients were entered in the study after informed consent forms had been signed. Patients with the following conditions were excluded: (1) maternal cardiac disease, (2) hypertension, (3) premature rupture of the membranes, (4) intrauterine growth retardation, (5) previous uterine surgery, (6) multiple gestation, (7) placenta previa, and (8) oligohydramnios. Requirements for inclusion into the study included (1) gestation ~36 weeks, (2) breech presentation, (3) absence of any contraindication (exclusion criteria), (4) normal sonographic appearance of fetus, placenta, and amniotic fluid volume, and (5) a reactive nonstress test. The procedure was conducted in the labor and de-
I
Method of delivery Breech
Vaginal
6 97
182 37
I
Abdominal
25 60
livery area. All patients underwent a thorough realtime ultrasound B scanning examination, a nons tress test, and a pelvic examination. A normal real-time B scan was defined as follows: singleton fetus in the breech position; adequate fluid (at least a 1.0 em pocket of fluid); biparietal diameter >8.5 em but < 10.5 em and an absence of gross fetal anomalies; or placenta previa. Patients were placed in the lateral semirecumbent position with left uterine displacement. An intravenous line was initiated with a crystalloid solution. A nonstress test was performed, and after a reactive pattern was noted, ritodrine hydrochloride was infused at 0.1 mg/min for 15 minutes prior to and during the procedure. Maternal heart rate and blood pressure were continuously monitored, as was the fetal heart rate. Version was accomplished by the classic "forward roll" technique if the fetal spine and head were on the same side of the maternal midline. The "back flip" method of Saling and Muller-Holve was used if the initial method failed. A second examiner manipulated the opposite fetal pole or assisted by vaginal elevation of the breech. The procedure was interrupted if patient discomfort became severe or if fetal heart rate decelerations were noted. In many cases, multiple attempts at version were performed. Once the fetus was turned satisfactorily, the f3-sympathomimetic infusion was discontinued and the fetus was maintained in the new attitude until uterine tone returned. Real-time B scan was used to confirm version success. For Rh-negative, unsensitized patients, Rh immune globulin was administered following version. After the procedure, fetal heart rate monitoring was continued until a reactive nonstress test was noted. The following maternal, fetal, and newborn variables were tabulated: (1) ease of version, defined according to the amount of time required to complete the maneuver and the number of attempts (an easy version was completed within 1 minute, with one or two attempts; a moderately difficult version was between 1 and 5 minutes, with two to five attempts; and a difficult version required longer than 5 minutes, with more than five attempts); (2) discomfort during the procedure (patients were asked to describe the procedure as painless or as mildly, moderately, or severely uncomfortable); (3) maternal heart rate and blood pressure; (4) fetal heart rate and uterine activity during and following the version; (5) vaginal bleeding, timing of rupture of the
902
Morrison et al.
April, 1986 Am J Obstet Gynecol
Table II. Effect of gestational age in version Successful*
Unsuccessful
Table IV. Mode of delivery for singleton breech fetuses at term
Gestational age (wk)
n
37-39 40-43
179 28
I
%
n
73 45
64 33
I
1979-1981
% 27 55
*p < 0.001.
All deliveries Cesarean birth (breech) Vaginal delivery (breech) Total
Table III. Effect of placental location on version
Anterior (n Posterior (n Total (n
=
= 128) = 176)
304)
n
%
n
%
12,942 359 230
61 39
13,221 216 150
59 41
589
366*
*p < 0.001.
Unsuccessful Placentallocation*
1982-1984
Successful
n
83 124
45 52
207
97
I
% 46 54
*p < 0.3.
membranes, and onset of labor; (6) intrapartum presentation and route of delivery; and (7) evidence of morbidity during the neonatal period. The X' analysis was used to detect statistical differences, and a p value of <0.05 was considered significant.
Results Version was successful in 207 of 304 patients (68%). In all of the successful versions, the fetuses had vertex presentations during labor, except six that reverted spontaneously to breech; five of them were delivered by cesarean birth (Table I). A subseptate uterus and a partial placenta previa were found during a cesarean delivery in two of these five cases. The abdominal delivery rate among the subjects (201) with a vertex presentation was 10%, and in no case was the indication for cesarean birth thought to be associated with the version. Of the 97 futile attempts, all deliveries were breech births and 62% were operative births (Table I). Of the successful versions, the vast majority were deemed easy (167), whereas 31 were moderately difficult and nine were difficult. Of these 207 parturients, 66 patients reported the procedure to be painless, 118 noted mild discomfort, and 23 described the version to be moderately uncomfortable. No patients reported severe or intolerable pain. Among the unsuccessful group, severe pain was the reason to discontinue the procedure in 12 subjects, whereas the type of pain noted subjectively was equally distributed (none, mild, moderate) among the other 85 patients in this group. In none of the 304 patients did rupture of the membranes, vaginal bleeding, or onset of labor occur within 24 hours of the attempted version. In none of the cases did uterine rupture or catastrophic maternal-fetal events occur. Fetal heart rate abnormalities (tach ycar-
dia, bradycardia, change in baseline, variable decelerations) occurred in 18% of the subjects during or after the procedure, but all responded to conservative management (oxygen, change in position, fluid administration with observation). Fetal heart rate abnormalities were a reason to abort version attempts in only six patients and were not related to the number of attempts or the ease of version. In no case was emergency delivery necessary. Likewise, hypotension, tachycardia, or other maternal side effects of the tocolytic agent did not necessitate abandonment of the procedure in any of the 304 patients. The total time for the procedure from entry into the delivery area until discharge was 160 ± 43 minutes among the successful group and 180 ± 51 minutes in those with failed version attempts. A significant difference in version success rate was noted when gestational age at the time of version was compared (Table II). At gestatational ages of 37 to 39 weeks, 179 of 243 attempts (73%) were successful in comparison with 45% (28 of 61) at 40 to 43 weeks (p < 0.001). In contrast, no difference was apparent in version success rate when placental location was used as the discriminator (Table III). Version was unsuccessful in 45 of 128 patients (46%) with anterior placentation and in 52 of 176 patients (54%) with posterior placental placement (p = 0.3). Careful examination during labor and at delivery disclosed no increased incidence of maternal-fetal-neonatal abnormalities related to the procedure. No increase in meconium-stained fluid, abnormal intrapartum fetal heart rate tracings, low Apgar scores, or neonatal or placental trauma was noted among the total group in comparison with a like number of term infants whose mothers did not undergo an attempted version. In none of the Rh-negative parturients was sensitization noted at delivery.
Comment The data from this study and a review of the literature leave little doubt that external cephalic version near term will reduce the incidence of breech presentation in labor. Between 90% and 97% of successful versions can be expected to remain as vertex presen-
Volume 154 Number 4
tations until the onset of labor. SolO In addition, few breech fetuses spontaneously convert to the vertex presentation after 36 weeks' gestation. 6 In this study, 68% of the breech presentations were converted to vertex successfully, and all but six fetuses presented in this attitude; figures were similar to those in other series. 7 -9 The impact of breech version on the cesarean birth rate has not been well defined, primarily because of diverse strategies regarding the management of breech presentations at term and because of the lack of large numbers of patients in most studies. We have been challenged to reduce the number of abdominal deliveries. 1I In our study, only 10% of successful versions required cesarean section, in comparison with 60% of the failure group. As shown in Table IV, the number of breech deliveries during the study period was significantly reduced (p < 0.001) in comparison with the preceding 3 years, although the total delivery rate increased by 5.4%. The percentage of cesarean versus vaginal deliveries did not differ during both periods for patients with a breech presentation during labor. As a result, the abdominal delivery rate was reduced by this strategy. Obviously, the higher the cesarean birth rate for breech presentation at term in any institution, the greater will be the impact of a program of external versIOn. The most pertinent question, other than the success of this modality, involves the safety of the procedure. lo • 12 In this study, no intrauterine deaths or neonatal losses attributed to a cord accident or placental abruption occurred. Other studies offer similar results.s° 1O Strict insistence on a normal fetal heart rate pattern both before and after version, as well as a normal real-time B scan, identifies the potentially compromised fetus and/or placental unit. Careful intraprocedure monitoring allows repetitive manipulation in individual cases where fetal heart rate irregularities transiently occur.
External cephalic version with tocolysis
903
In conclusion, these data indicate that in the carefully monitored and selected patient population, external version, near term, of the breech presentation can safely increase the vertex attitude by the onset of labor. This strategy would appear to reduce the need for cesarean birth. Constant vigilance, however, is necessary during the procedure to ensure that one does not damage the fetus or the parturient. REFERENCES 1. Manzke H. Morbidity among infants born in breech presentation.] Perinat Med 1978;6:127-40. 2. Collea]V, Rabin SC, Weghorst GR, et al. The randomized management of term frank breech presentation: vaginal delivery versus cesarean section. AM] OBSTET GYNECOL 1978;131:186-95. 3. Main DM, Main EK, Maurer MM. Cesarean section versus vaginal delivery for the breech fetus weighing less than 1,500 grams. AM] OBSTET GYNECOL 1983;146:580-4. 4. Gimovsky ML, Wallace RL, Schifrin BS, et al. Randomized management of the nonfrank breech presentation at term: a preliminary report. AM ] OBSTET GYNECOL 1983;146:34-40. 5. Friedlander D. External cephalic version in the management of breech presentation. AM ] OBSTET GYNECOL 1966;95:906-13. 6. Ranney B. The gentle art of external cephalic version. AM] OBSTET GYNECOL 1973;116:239-51. 7. Saling E, Muller-Holve W. External cephalic version under tocolysis.] Perinat Med 1975;3: 115-22. 8. Van Dorsten ]P, Schifrin BS, Wallace RL. Randomized control trial of external cephalic version with tocolysis in late pregnancy. AM] OB5TET GYNECOL 1981; 141 :417-24. 9. Fall 0, Nilsson BA. External cephalic version in breech presentation under tocolysis. Obstet Gynecol 1979;53: 712-5. 10. Phelan, ]P, Stine LE, Mueller E, et al. Observations of fetal heart rate characteristics related to external cephalic version and tocolysis. AM ] OB5TET GYNECOL 1984; 149:658-61. 11. Gleicher N. Cesarean section rates in the United States: the short-term failure of the National Consensus Development Conference in 1980. ]AMA 1984;252:3273-6. 12. Berg D, Kunze U. Critical remarks on external cephalic version under tocolysis: report on a case of antepartum fetal death.] Perinat Med 1977;5:32-3.