Aust NZ J Obstet Gynaecol 1992; 32: 3: 213
Viginal Delivery After Caesarean Section Marc Miller’, MBBS and Leo R. Leader2, MD, FRACOG The Royal Hospital for Women, Sydney, New South Wales
EDITORIAL COMMENT: Thisprospective study reports excellent results although the 64% vaginal delivery ratefor those having a trial of scar is less than the other reported series quoted by the authors (table 5). The I case of uterine rupture occurring in the 125 women who had a trial of labour may have been called a ‘dehiscence’by many since there was no bleeding or haematoma, and importantly no harm to fetus or mother. We respectfully disagree with the authors final comment that ‘most women with a previous Caesarean section can safely deliver vaginally’ since this study showed that only 64% (80 of 125) of those having a trial of labour, or 25% (80 of 318) of consecutive women with a previous Caesarean scar could safely deliver vaginally. It seemed to our reviewer that an unmentioned takeaway message was that good clinical judgement was required to select the 61% (193 of 318) of women for elective repeat Caesarean section, as well as providing superior care during labour to those who elected to do so.
Summary: In a prospective study of 318 consecutive pregnancies complicated by previous Caesarean section, 193 (61%) had an elective repeat Caesarean section, 125 (39%) had a trial of labour and 80 (64%) of these women achieved a vaginal delivery. The incidence of uterine rupture was 0.8% (1 of 125). The vaginal delivery rate was not influenced by the indication for the first Caesarean section (including cephalopelvic disproportion), birth-weight, health insurance status, use of epidural analgesia or oxytocin in labour. Perinatal morbidity was unaffected by the mode of delivery and maternal morbidity was comparable following elective and emergency repeat Caesarean section. Patients having a vaginal delivery spent significantly less time in hospital. We conclude that vaginal delivery after lower segment Caesarean section is safe and should be considered in most patients after a critical review of the indication for the first Caesarean section.
The maternal mortality rate following Caesarean section is 4 times higher than after vaginal delivery (1). Despite this, the Caesarean section rate has continued to rise and repeat Caesarean section has made a large contribution to this increase. In New South Wales ‘previous Caesarean’ is now the leading indication for Caesarean section and comprises 22% of all indications (2). In many cases the decision to have another Caesarean section is based on the indication for the first Caesarean section. If this was performed for cephalopelvic disproportion (CPD), many obstetricians are unwilling to allow their patients a trial of labour. It has also been shown that the Caesarean section rate is higher in patients with private health insurance compared to public patients (3,4). This prospective study was therefore undertaken to review the management of women with a previous 1. Registrar. 2. Senior Lecturer.
Address for correspondence: Dr. Marc Miller, Wollongong Hospital, Crown Street, Wollongong, NSW, 2500.
Caesarean section delivering in a Sydney teaching hospital, to determine those variables which may influence the likelihood of vaginal delivery and assess the perinatal and maternal morbidity associated with vaginal delivery after Caesarean section.
PATIENTS AND METHODS Three hundred and eighteen consecutive patients with 1 or more previous Caesarean sections delivering at the Royal Hospital for Women between July, 1989 and June, 1990 inclusive were recruited. The medical records of these patients were examined and details of all previous pregnancies including the first Caesarean section, the conduct of labour in the current pregnancy and perinatal and maternal complications were collected. Indication for Caesarean section was taken to be the main indication listed in the operation notes and postpartum fever was defined as a temperature of 38 “C or more on 2 occasions more than 24 hours apart. Statistical analysis was performed using Chi-square for discrete variables and Student’s t-test (paired or unpaired where appropriate) for continuous variables to assess the difference between groups and a p value of less than 0.05 was regarded as significant.
214
AUST.AND N.Z. JOURNAL OF OBSTETRICS AND GYNAECOLOGY
Table 1. Indications for Elective Repeat Caesarean Section (%)
n More than one previous Caesarean Cephalopelvic disproportion One previous Caesarean High head Breech presentation Medical complication Previous classical Caesarean Patient request Other indications
62 34 27 16 12 10 4 3 25
Table 2. Patient Characteristics According to Mode of Delivery
Age (years) Weight (Kg) Parity Gestation (weeks)
Elective Caesarean (n = 193)
Emergency Caesarean (n = 45)
Vaginal delivery (n = 80)
Mean SD 32.09 4.59 64.28 13.59 2.48 0.68 37.99 1.98
Mean SD 31.13 5.04 65.53 11.97 2.29 0.57 38.73 2.73
Mean SD 31.46 4.71 63.06 12.16 2.65 0.98 38.28 3.41
Results are shown as mean
+ 1- standard deviation (SD)
RESULTS
Pregnancy outcome The 318 patients with a previous Caesarean section represented 7.2% of the 4,395 deliveries at the Royal Hospital for Women during the study period. Of these 318 patients 193 (61%) were delivered by elective repeat Caesarean section and the indications are listed in table 1. In 14% the sole indication for repeat Caesarean section was 1 previous Caesarean section. The remaining 125 patients (39%) had a trial of labour and of these 80 (64%) achieved a vaginal delivery. There was no significant difference in patient characteristics according to the mode of delivery (table 2). In this study there were 121 patients who had had a previous Caesarean section for CPD and only 25 of these (20.7%) were allowed a trial of labour. This was significantly fewer than women labouring after a Caesarean section for fetal distress (59.1%) or breech presentation (52.1%). A vaginal delivery was achieved in 13 of 25 women (52%) with a previous Caesarean for CPD, compared to 21 of 25 (84%) with a prior Caesarean for breech presentation and 14 of 26 (54%) with a prior Caesarean for fetal distress. These differences were not statistically significant. The infants' birth-weight did not influence the outcome of labour in that in women having a trial of labour, 104 had babies with birth-weights less than 4,000 g and of these 67 (64.4%) delivered vaginally. Nine women had babies with birth-weights 4,000 g or more and 6 (66.6%) of them delivered vaginally. The health insurance status of patients did not significantly affect the mode of delivery. One hundred and fifty-five (62.5%) of the 248 patients with private health
insurance had an elective repeat Caesarean section compared to 38 (54.3%) of the 70 public patients. Only 28 patients had X-ray pelvimetry prior to being allowed to labour. In this small group, patients having an anteroposterior diameter of 11.5 cm or more had the same vaginal delivery rate as those with an A P value of less than 11.5 cm. Of the 125 patients having a trial of labour 88 (70.4%) had continuous electronic fetal heart rate monitoring, 49 (39.2%) received oxytocin in labour and 61 (48.8%) had epidural analgesia. Thirty-one (63.3%) of the women receiving oxytocin achieved a vaginal delivery compared to 49 (64.5%) of those who did not. Forty eight (78.7%) of the women having epidural analgesia achieved a vaginal delivery compared to 32 (56.1%) who did not. None of these differences were statistically significant. Two patients with more than 1 previous Caesarean section had a trial of labour and 1 delivered vaginally while the other had an emergency Caesarean section. No women with twins or breech presentation in the current pregnancy were allowed to labour in this study.
Maternal morbidity One uterine rupture occurred during the study period resulting in an incidence of 0.8% (1 of 125 having trial of labour). This patient had previously had 1 lower segment Caesarean section for fetal distress and in the current pregnancy laboured for 11 hours with oxytocin augmentation and epidural analgesia before being delivered by emergency Caesarean section when cardiotocographic changes of fetal distress developed. A lateral defect in the lower segment scar was found at repeat Caesarean section and a live male infant with Apgar scores of 9 and 10 was delivered. There were no subsequent maternal complications. There was no difference in the incidence of postpartum fever, wound inflammation, or blood transfusion when delivery by emergency Caesarean and elective Caesarean section were compared. Fifteen of the 44 patients (34.9%) having an emergency Caesarean were given antibiotics postoperatively compared to 26 of the 193 patients (13.5%) following elective Caesarean section (p < 0.005). The mean duration of hospital stay was significantly shorter following vaginal delivery than following either emergency or elective repeat Caesarean section (table 3) (p
Viginal Delivery After Caesarean Section Marc Miller’, MBBS and Leo R. Leader2, MD, FRACOG The Royal Hospital for Women, Sydney, New South Wales
EDITORIAL COMMENT: Thisprospective study reports excellent results although the 64% vaginal delivery ratefor those having a trial of scar is less than the other reported series quoted by the authors (table 5). The I case of uterine rupture occurring in the 125 women who had a trial of labour may have been called a ‘dehiscence’by many since there was no bleeding or haematoma, and importantly no harm to fetus or mother. We respectfully disagree with the authors final comment that ‘most women with a previous Caesarean section can safely deliver vaginally’ since this study showed that only 64% (80 of 125) of those having a trial of labour, or 25% (80 of 318) of consecutive women with a previous Caesarean scar could safely deliver vaginally. It seemed to our reviewer that an unmentioned takeaway message was that good clinical judgement was required to select the 61% (193 of 318) of women for elective repeat Caesarean section, as well as providing superior care during labour to those who elected to do so.
Summary: In a prospective study of 318 consecutive pregnancies complicated by previous Caesarean section, 193 (61%) had an elective repeat Caesarean section, 125 (39%) had a trial of labour and 80 (64%) of these women achieved a vaginal delivery. The incidence of uterine rupture was 0.8% (1 of 125). The vaginal delivery rate was not influenced by the indication for the first Caesarean section (including cephalopelvic disproportion), birth-weight, health insurance status, use of epidural analgesia or oxytocin in labour. Perinatal morbidity was unaffected by the mode of delivery and maternal morbidity was comparable following elective and emergency repeat Caesarean section. Patients having a vaginal delivery spent significantly less time in hospital. We conclude that vaginal delivery after lower segment Caesarean section is safe and should be considered in most patients after a critical review of the indication for the first Caesarean section.
The maternal mortality rate following Caesarean section is 4 times higher than after vaginal delivery (1). Despite this, the Caesarean section rate has continued to rise and repeat Caesarean section has made a large contribution to this increase. In New South Wales ‘previous Caesarean’ is now the leading indication for Caesarean section and comprises 22% of all indications (2). In many cases the decision to have another Caesarean section is based on the indication for the first Caesarean section. If this was performed for cephalopelvic disproportion (CPD), many obstetricians are unwilling to allow their patients a trial of labour. It has also been shown that the Caesarean section rate is higher in patients with private health insurance compared to public patients (3,4). This prospective study was therefore undertaken to review the management of women with a previous 1. Registrar. 2. Senior Lecturer.
Address for correspondence: Dr. Marc Miller, Wollongong Hospital, Crown Street, Wollongong, NSW, 2500.
Caesarean section delivering in a Sydney teaching hospital, to determine those variables which may influence the likelihood of vaginal delivery and assess the perinatal and maternal morbidity associated with vaginal delivery after Caesarean section.
PATIENTS AND METHODS Three hundred and eighteen consecutive patients with 1 or more previous Caesarean sections delivering at the Royal Hospital for Women between July, 1989 and June, 1990 inclusive were recruited. The medical records of these patients were examined and details of all previous pregnancies including the first Caesarean section, the conduct of labour in the current pregnancy and perinatal and maternal complications were collected. Indication for Caesarean section was taken to be the main indication listed in the operation notes and postpartum fever was defined as a temperature of 38 “C or more on 2 occasions more than 24 hours apart. Statistical analysis was performed using Chi-square for discrete variables and Student’s t-test (paired or unpaired where appropriate) for continuous variables to assess the difference between groups and a p value of less than 0.05 was regarded as significant.
214
AUST.AND N.Z. JOURNAL OF OBSTETRICS AND GYNAECOLOGY
Table 1. Indications for Elective Repeat Caesarean Section (%)
n More than one previous Caesarean Cephalopelvic disproportion One previous Caesarean High head Breech presentation Medical complication Previous classical Caesarean Patient request Other indications
62 34 27 16 12 10 4 3 25
Table 2. Patient Characteristics According to Mode of Delivery
Age (years) Weight (Kg) Parity Gestation (weeks)
Elective Caesarean (n = 193)
Emergency Caesarean (n = 45)
Vaginal delivery (n = 80)
Mean SD 32.09 4.59 64.28 13.59 2.48 0.68 37.99 1.98
Mean SD 31.13 5.04 65.53 11.97 2.29 0.57 38.73 2.73
Mean SD 31.46 4.71 63.06 12.16 2.65 0.98 38.28 3.41
Results are shown as mean
+ 1- standard deviation (SD)
RESULTS
Pregnancy outcome The 318 patients with a previous Caesarean section represented 7.2% of the 4,395 deliveries at the Royal Hospital for Women during the study period. Of these 318 patients 193 (61%) were delivered by elective repeat Caesarean section and the indications are listed in table 1. In 14% the sole indication for repeat Caesarean section was 1 previous Caesarean section. The remaining 125 patients (39%) had a trial of labour and of these 80 (64%) achieved a vaginal delivery. There was no significant difference in patient characteristics according to the mode of delivery (table 2). In this study there were 121 patients who had had a previous Caesarean section for CPD and only 25 of these (20.7%) were allowed a trial of labour. This was significantly fewer than women labouring after a Caesarean section for fetal distress (59.1%) or breech presentation (52.1%). A vaginal delivery was achieved in 13 of 25 women (52%) with a previous Caesarean for CPD, compared to 21 of 25 (84%) with a prior Caesarean for breech presentation and 14 of 26 (54%) with a prior Caesarean for fetal distress. These differences were not statistically significant. The infants' birth-weight did not influence the outcome of labour in that in women having a trial of labour, 104 had babies with birth-weights less than 4,000 g and of these 67 (64.4%) delivered vaginally. Nine women had babies with birth-weights 4,000 g or more and 6 (66.6%) of them delivered vaginally. The health insurance status of patients did not significantly affect the mode of delivery. One hundred and fifty-five (62.5%) of the 248 patients with private health
insurance had an elective repeat Caesarean section compared to 38 (54.3%) of the 70 public patients. Only 28 patients had X-ray pelvimetry prior to being allowed to labour. In this small group, patients having an anteroposterior diameter of 11.5 cm or more had the same vaginal delivery rate as those with an A P value of less than 11.5 cm. Of the 125 patients having a trial of labour 88 (70.4%) had continuous electronic fetal heart rate monitoring, 49 (39.2%) received oxytocin in labour and 61 (48.8%) had epidural analgesia. Thirty-one (63.3%) of the women receiving oxytocin achieved a vaginal delivery compared to 49 (64.5%) of those who did not. Forty eight (78.7%) of the women having epidural analgesia achieved a vaginal delivery compared to 32 (56.1%) who did not. None of these differences were statistically significant. Two patients with more than 1 previous Caesarean section had a trial of labour and 1 delivered vaginally while the other had an emergency Caesarean section. No women with twins or breech presentation in the current pregnancy were allowed to labour in this study.
Maternal morbidity One uterine rupture occurred during the study period resulting in an incidence of 0.8% (1 of 125 having trial of labour). This patient had previously had 1 lower segment Caesarean section for fetal distress and in the current pregnancy laboured for 11 hours with oxytocin augmentation and epidural analgesia before being delivered by emergency Caesarean section when cardiotocographic changes of fetal distress developed. A lateral defect in the lower segment scar was found at repeat Caesarean section and a live male infant with Apgar scores of 9 and 10 was delivered. There were no subsequent maternal complications. There was no difference in the incidence of postpartum fever, wound inflammation, or blood transfusion when delivery by emergency Caesarean and elective Caesarean section were compared. Fifteen of the 44 patients (34.9%) having an emergency Caesarean were given antibiotics postoperatively compared to 26 of the 193 patients (13.5%) following elective Caesarean section (p < 0.005). The mean duration of hospital stay was significantly shorter following vaginal delivery than following either emergency or elective repeat Caesarean section (table 3) (p
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