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Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Objective To determine the mode of the next delivery for primigravid women who have an elective caesarean section for breech presentation.

Design Retrospective cohort study.

Setting University teaching hospital.

Population All primigravid women who had an elective caesarean section for a singleton pregnancy in the years 1992 to 1997 and who delivered their next baby in the hospital before 1999.

Methods Review of hospital computerised records.

Main outcome measures Mode of delivery and fetal presentation at next delivery.

Results Of 194 women who had an elective caesarean section with a breech presentation as a primigravida, 19 (9.8%) had a breech presentation at the time of elective caesarean section for their next baby compared with only two (1.7%) in the 121 women who had an elective caesarean section with a cephalic presentation as a primigravida (RR 5.9 [95% CI 1.4–25.0]). Despite the increased likelihood of another breech presentation, the overall repeat section rate was 43.8% (n= 85) in women with a previous breech presentation (n= 194), compared with 61.2% (n= 74) in women with a previous cephalic presentation (n= 121) (RR 0.72 [95% CI 0.58–0.89]). Of those women allowed to labour after elective caesarean section as a primigravid, the vaginal birth rate was 109/130 (84%) if the presentation previously was breech compared with 47/69 (68%) if the presentation previously was cephalic (RR 1.2 [95% CI 1.03–1.50]).

Conclusions Women who have an elective caesarean section for a breech presentation in their first pregnancy have about a 1 in 10 chance of having an elective caesarean section for a breech presentation in their second pregnancy. Overall, the incidence of repeat caesarean section for their second baby was 43.8%, and of those allowed to labour, 84% achieved a vaginal delivery. These results compared favourably with women who had an elective caesarean section with a cephalic presentation in their first pregnancy. This information is important in advising primigravid women with a breech presentation about longer term implications of elective caesarean section. It also allows healthcare managers to anticipate the resource implications of any changes in clinical practice for women with a breech presentation in their first pregnancy.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

A feature of modern obstetrics has been the increase in the incidence of elective caesarean section for breech presentation. In our hospital, 68.4% of primigravidae and 47.7% of multigravidae had an elective caesarean section with a breech presentation in 1998. In other countries, the caesarean section rate for breech presentation is now of the order of 80%1. As a consequence of the recent multicentre trial on planned caesarean section versus planned vaginal birth for breech presentation at term2, it is expected that the incidence of elective caesarean sections for breech presentation will increase worldwide in the future. The latest RCOG Guidelines on the treatment of breech presentation are also likely to accelerate this trend3. This practice has implications not just for the index pregnancy, however, but also increases the likelihood of a woman, particularly a primigravida, requiring a repeat caesarean section in subsequent pregnancies4.

It has been suggested in previous reports that women who have a caesarean section for a breech presentation are more likely to deliver vaginally subsequently than women who have a caesarean section for other indications5,6. These reports are inconclusive because of confounding variables such as parity and previous labours. To eliminate these two important variables, we studied primigravid women who had an elective caesarean section for a breech presentation and who delivered their next baby in our hospital. The study examined the mode of delivery for their second baby.

Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

The study was confined to primigravid women who had an elective caesarean section in the hospital between 1992 and 1997 inclusively and who delivered subsequently in the hospital before 1999 a baby weighing 500 g or more. The women were identified from the hospital's computerised records. We compared the mode of delivery for the second baby in women who had a breech presentation at the time of elective caesarean section for their first baby with the mode of delivery in women who had a cephalic presentation at the time of elective caesarean section for their first baby.

During the study, vaginal birth after caesarean section was encouraged. However, women with a breech presentation at term and a previous caesarean section were delivered at term by elective repeat section. Pelvimetry was not used to decide the optimum mode of delivery. In labour, the fetal heart was monitored electronically and epidural analgesia was available. Oxytocin was used to speed labour only after careful clinical evaluation by a senior obstetrician4. There were no exclusion criteria.

In our analysis, we estimated the relative risks and their 95% confidence intervals using Stata Release 7.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Before 1999, 194 women delivered their second baby who had had an elective caesarean section in their first pregnancy for a breech presentation between 1992 and 1997 inclusive. During the same period, 121 women delivered their second baby who had had an elective caesarean section for their first baby with a cephalic presentation. Of these 121 women, the indication for the previous elective section was intrauterine growth restriction with or without pre-eclampsia (n= 88), previous uterine surgery (n= 8), insulin dependent diabetes mellitus (n= 7), placenta praevia (n= 5) and other indications (n= 13). The mode of delivery for the second baby is shown in Table 1. The fetal presentation at repeat elective caesarean section for the second baby is shown in Table 2. Women who had an elective caesarean section with a breech presentation in their first pregnancy were more likely to have a breech presentation in their second pregnancy, all these women being delivered by elective caesarean section (RR 5.9 [95% CI 1.4–25.0]).

Table 1.  Mode of delivery for the second baby after elective caesarean section for the first baby.
 Previous breech presentation (n= 194)Previous cephalic presentation (n= 121)
Spontaneous vaginal72 (37.1%)34 (28.1%)
Instrumental vaginal37 (19.1%)13 (10.7%)
Emergency section21 (10.8%)22 (18.2%)
Elective section64 (33.0%)52 (43.0%)
Table 2.  Presentation at repeat elective section for the second baby.
 Previous breech presentation (n= 194)Previous cephalic presentation (n= 121)
Breech19 (9.8%)2 (1.7%)
Cephalic45 (23.2%)50 (41.3%)
Total elective sections64 (33.0%)52 (43.0%)

Despite the increased likelihood of another breech presentation, however, the overall repeat section rate was 43.8% in the women with a previous breech presentation compared with 61.2% in the women with a previous cephalic presentation (RR 0.72 [95% CI 0.58–0.89]). Of those allowed to labour after elective caesarean section as a primigravid, the vaginal birth rate was 84% (109 of 130) if the presentation previously was breech, compared with 68% (47 of 69) if the presentation previously was cephalic (RR 1.2 [95% CI 1.03–1.5]).

The indications for repeat emergency caesarean section in labour for the second baby are shown in Table 3. The incidence of caesarean sections for dystocia was 6.9% in the previous breech group compared with 17.4% in the previous cephalic group (RR 0.40 [95% CI 0.18–0.88]). We considered that birthweight might explain differences in the overall section rates. In the previous breech group, the mean birthweight was 3.472 kg and 16 babies weighed >4.0 kg; in the previous cephalic group, the mean birthweight was 3.413 kg and 18 babies weighed >4.0 kg. Possible maternal confounding variables, such as body mass index, were not recorded in the clinical records or in the computerised database; this precluded a multivariate analysis.

Table 3.  Indications for repeat emergency caesarean section in labour.
 Previous breech presentation (n= 130)Previous cephalic presentation (n= 69)
Fetal distress7 (5.4%)4 (5.8%)
Dystocia9 (6.9%)12 (17.4%)
Other5 (3.8%)6 (8.7%)
Total21 (16.1%)22 (31.9%)

The indications for repeat elective caesarean section for the second baby are shown in Table 4. Despite the higher incidence of breech presentations delivered by elective caesarean section, women with a previous elective caesarean section for breech presentation were less likely to require a repeat elective caesarean section overall than the women with a previous elective caesarean section with a cephalic presentation, but this difference did not reach the conventional level of statistical significance (RR 0.77 [95% CI 0.58–1.02]).

Table 4.  Indications for repeat elective caesarean section.
 Previous breech presentation (n= 194)Previous cephalic presentation (n= 121)
Breech presentation19 (9.8%)2 (1.7%)
Other45 (23.2%)50 (41.3%)
Total64 (33.0%)52 (43.0%)

In the women who had a previous breech presentation with a cephalic presentation in the index pregnancy, the indications for repeat elective section were repeat alone (n= 17), intrauterine growth restriction (n= 11), pre-eclampsia (n= 7), diabetes mellitus (n= 4) and others (n= 6). In the previous cephalic presentation with a cephalic presentation again, the indications for repeat elective section were repeat alone (n= 15), intrauterine growth restriction (n= 8), pre-eclampsia (n= 9), diabetes mellitus (n= 6) and others (n= 12). The practice in the hospital during this study was to avoid induction of labour in women with a previous section if the cervix was unfavourable, to avoid the risk of uterine rupture in labour4.

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Our hospital is responsible for delivering one in seven Irish women. The caesarean section rate in the hospital in primigravidae increased from 15.4% in 1992 to 16.9% in 1997 due in part to an increase in elective caesarean sections for breech presentation, which prompted this present study.

In a large review of delivery following previous caesarean section5, the incidence of vaginal delivery with a trial of labour in women with a previous caesarean section was analysed by indication for primary section. In the ‘breech/malpresentation’ category, the incidence of vaginal delivery was 84% (n= 1189), compared with 77% (n= 659) in the ‘fetal distress’ category, 65% (n= 2528) in the ‘dystocia’ category and 77% (n= 1945) in the ‘other indications’ category. Analysis by indication for primary section may be unreliable, however, because it may be affected by variables such as a previous labour or previous vaginal delivery. To eliminate these variables, therefore, we confined our study to women who had a previous elective caesarean section only.

Our results confirm that primigravid women who had an elective section for breech presentation are more likely to have a subsequent vaginal delivery than primigravid women who had an elective section for other reasons. Given the widespread policy of elective section in women with two or more previous sections, it follows that they are also less likely to need a caesarean section for their third and subsequent births if a vaginal delivery can be achieved in the second pregnancy. The higher incidence of vaginal delivery occurred despite the fact that women who had an elective caesarean section for breech presentation are more likely to have a subsequent section for breech presentation.

We are unable to explain the higher incidence of vaginal delivery in the previous breech presentation group, particularly as the incidence of both elective and emergency sections was lower compared with the previous cephalic presentation group. It may be due to intrinsic biological differences in the women or it may reflect a higher threshold by obstetricians for repeating a caesarean section in women whose previous section was for a breech presentation.

Whatever the explanation, our results are useful in advising primigravid women who require an elective caesarean section about the mode of delivery in subsequent pregnancies. It also provides more detailed information about the long term effects of increasing the rate of planned caesarean section in first time mothers, as recently recommended in the Royal College of Obstetricians and Gynaecologists Guideline on the Management of Breech Presentation3. In view of the increasing number of women who have had a previous elective section for breech presentation, further research is indicated into labour in the presence of a uterine scar.

Acknowledgements

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

We thank Mr Ronan Conroy, Biostatistics Lecturer, Royal College of Surgeons in Ireland.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References
  • 1
    Penn Z, Ghaem-Maghami S. Indications for caesarean section. Best Pract Res Clin Obstet Gynaecol 2001;15: 115.
  • 2
    Hannah ME, Hannah WJ, Hewson SA, Hodnett ED, Saigal S, Willan AR. Planned caesarean section versus planned vaginal birth for breech presentation at term: a randomised multicentre trial. Lancet 2000;356: 13751383.
  • 3
    Johanson RB. The management of breech presentation, Guideline No. 20. Royal College of Obstetricians and Gynaecologists, April 2001.
  • 4
    Turner MJ. Delivery after one previous cesarean section. Am J Obstet Gynecol 1997;176: 741744.
  • 5
    Enkin M. Labour and delivery following previous caesarean section. In: ChalmersI, EnkinM, KierseMJNC, editors. Effective Care in Pregnancy and Childbirth. Oxford : Oxford University Press, 1989: 11961215.
  • 6
    Shipp TD, Zelop CM, Repke JT, Cohen A, Caughey AB, Lieberman E. Labor after previous cesarean: influence of prior indication and parity. Obstet Gynecol 2000;95: 913916.