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Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. References

Objective To determine the outcome of subsequent labour in primiparous women after a caesarean section for delay in descent in the second stage of labour in cephalic presentations with or without trial of instrumental vaginal delivery.

Design Retrospective follow up study.

Setting Medical Centre Leeuwarden, The Netherlands.

Participants All primiparous parturients who delivered after prior caesarean section during the second stage of labour in the period 1986–1998.

Methods Data concerning the outcome of the first subsequent delivery were gathered from delivery notes and patients charts. The group of women was subdivided into those with or without trial of instrumental vaginal delivery during the previous labour.

Results Of 132 women, 29 (22%) underwent a planned repeat caesarean section. Of the 103 women who were allowed a trial of labour, 82 (80%) were successful in having a vaginal delivery, and 21 (20%) had a second caesarean section. Of the 74 women with a failed trial of instrumental delivery during the previous labour, 19 had a planned repeat caesarean section and 41 of the remaining 55 (75%) had a successful trial of labour.

Conclusions In women with a cephalic presentation who had an arrest of descent in the second stage of labour during their first delivery, the chances of vaginal delivery in their next pregnancy are high, even after a failed instrumented vaginal delivery, and a trial of labour can usually be pursued.


INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. References

Several studies suggest that for adequately screened women with a prior caesarean section, in a hospital environment, a trial of labour is as safe or even safer than elective repeat caesarean section1,2. More than 90% of women with a history of previous low transverse section are delivered by repeat caesarean section in the United States3. Successful trial of labour shortens the duration of hospital stay and gives more patient satisfaction. Caesarean delivery at full dilatation is associated with a much reduced chance of successful vaginal birth in a subsequent pregnancy4. Delay in descent of the head in labour is associated with cephalo-pelvic disproportion5. Many obstetricians may be unwilling to allow their patients a trial of labour if the caesarean section was preceeded by a delay in descent in the second stage and failed attempt of instrumental delivery by vacuum or forceps. Women with prolonged or dysfunctional labour at the first birth are less likely to attempt a subsequent vaginal delivery, perhaps because of the memory of a painful, long and unsuccessful first labour6. This study was undertaken to determine the outcome of trial of labour in such women. Assessment included whether prior failed trial of instrumental vaginal delivery and birthweight have any predictive value for the chances of a successful trial of labour.

METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. References

In our region about 50% of the obstetric population are delivered by general practitioners or midwives; these births take place primarily at home (40%) or in a hospital (10%). Because of risk factors the remaining 50% are delivered in a hospital under the care of a gynaecologist; 10,235 such deliveries were recorded at the Medical Center of Leeuwarden, The Netherlands between January 1986 and January 1993. During this period 1676 women (16.4%) were delivered by caesarean section; the overall caesarean section rate including home births in our region is about 8%–9%.

Inclusion criteria for the study were term first pregnancy with a singleton fetus in vertex position in which caesarean section had been performed for delay in descent during the second stage of labour. All caesarean sections were performed by an experienced consultant obstetrician; all these women were fully dilated and were experiencing delay during the second stage. Women were not included in the study if slowness in the early second stage or fetal distress precipitated the decision for caesarean section. There were 204 such women, representing 12.2% of all women who had caesarean sections. Each woman's record was reviewed by one of the authors for the following: parity, trial of vaginal instrumental delivery, birthweight and neonatal outcome, success or failure of an eventual trial of labour in the first subsequent pregnancy. Results of the next pregnancy were followed up until 1 January 1998. In the subsequent pregnancy a trial of labour was usually pursued. Progress was monitored on a regular basis and when necessary labour was augmented with oxytocin, but the decision to allow a trial of labour was at the discretion of the individual doctor respecting the woman's request for a particular mode of birth.

For comparison of the results and statistical analysis probability values (P) were calculated using Student's t test.

RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. References

Of 204 primiparous women who had had a caesarean section due to delay in descent of the head in the second stage of labour, 61 were excluded as they were not delivered again and nine because they were lost to follow up. Two women were excluded as fetal distress during the trial of labour precipitated the decision for secondary caesarean section.

Of the remaining 132 primiparous women, 29 (22%) had a planned caesarean section in their next pregnancy for a variety of reasons (Tables 1 and 2). Trial of labour was attempted in 103 women (78%). Of these, 82 were successful and 21 had a further section. Of the 82 successful vaginal births, 40 were assisted by vacuum (n= 32) or forceps (n= 8). Trials of labour were mostly of spontaneous onset: eight women had an induction for various reasons with a successful vaginal birth in five women. Where the previous caesarean section had followed a failed attempt of instrumental delivery by vacuum (n= 7 1) or forceps (n= 3), successful vaginal delivery after a trial of labour (n= 55) occurred in 41 women (75%). Of 21 women with a fetal malpresentation, such as a brow presentation or occiput posterior position during the prior labour, five were delivered by planned repeat caesarean section, and 14 (88%) succeeded in having a vaginal delivery. Overall, of the 132 women 50 (37.9%) had an elective or secondary caesarean section in the subsequent pregnancy, giving an over-all rate of succesful vaginal birth of 62.1%. Excluding planned repeat caesarean sections, the rate of vaginal birth after a trial of labour was 79.6%.

Table 1.  Outcome of delivery after previous caesarean section (CS) for arrest of descent in the second stage of labour in cephalic presentations with or without trial of vacuum delivery in the first labour (n= 132). Values are given as n (%).
 Trial of vacuum (n= 74)No trial of vacuum (n = 58)TOTAL (n = 132)
Elective CS191029
Trial of labour5548103
Vaginal delivery
  Spontaneous19 (35)23 (48)42 (41)
  Instrumental22 (40)18 (37)40 (39)
Secondary CS14 (25)7 (15)21 (20)
Table 2.  Reasons for planned second section after caesarean section for arrest of descent.
ReasonsPrimiparous (n= 29)
Cephalo-pelvic disproportion8
Elective (anxiety)8
Breech presentation9
Transverse lie1
Placenta previa1
Diabetic retinopathy1
Intrauterine infection1

The incidence of uterine rupture was 1%: one woman had an uncomplicated first stage during a trial of labour without oxytocin stimulation. Due to delay in descent during the second stage a secondary caesarean section was performed. During the procedure a bloodless scar dehiscence was found without further maternal or fetal morbidity. Neonatal out-come was affected by one stillbirth in a woman with planned repeat caesarean section: a child with Down's syndrome appeared stillborn due to cerebral bleeding. In the second delivery Apgar scores following vaginal delivery were not significantly different when compared with Apgar scores after elective or secondary caesarean section. Failed instrumental delivery followed by caesarean section in the first delivery was not associated with increased fetal morbidity.

Birthweight did not influence the clinician's decision regarding a trial of labour or elective caesarean section, as no difference in mean birthweight was found between infants born by planned caesarean section and those born after a trial of labour (Table 3; P= 0.25). Within the group with a trial of labour (n= 103) infants delivered via spontaneous vaginal birth (n= 42) had a lower birthweight compared with infants delivered by vacuum or forceps (n= 40; P= 0.0085), or compared with all infants delivered via vaginal instrumental or abdominal delivery (n = 61; P= 0.0062).

Table 3.  Mode of delivery in relation to mean birthweight among primiparous women with a previous caesarean section (CS) (n= 132). SEM = standard error of the mean.
 Total (n)Mean birthweight second delivery (g)SEM
  1. *Elective CS vs trial of labour; P= 0.25.

  2. † Spontaneous vaginal birth vs instrumental and operative delivery; P= 0.0062.

  3. § Spontaneous vaginal birth vs instrumental vaginal delivery; P= 0.0085.

Elective CS*293475103
Vaginal delivery
Spontaneous*†§42342683
Instrumental*†§40377297
Secondary CS*213682120

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. References

We have demonstrated that a trial of labour is possible in most women with a previous caesarean section for delay in descent in the second stage of labour; in our series there was an overall success rate for vaginal delivery of 80% for 103 women attempting trial of labour. Several studies3,4,7–14 report the outcome of trial of labour after previous caesarean delivery for cephalo-pelvic disproportion, but only a few small studies consider the outcome where the previous operative delivery occurred for delay in descent during the second stage of labour. Ollendorf et al.14 reported an overall success rate of vaginal birth after caesarean section of 69% in 35 women with prior full dilatation. Likewise Duff et al3 reported a success rate of 65% in 17 women who had a delay in descent in the previous pregnancy. Hoskins and Gomez4 reported a success rate of only 13% in 245 woman who had a caesarean birth at full dilatation in their previous pregnancy, concluding that the chance of success of trial of labour is very small in women who had had a caesarean delivery at full dilatation.

However, our study demonstrates that a history of caesarean delivery for delay in descent in the second stage of labour does not necessarily mean that there is a diagnosis of cephalo-pelvic disproportion, even if trial of instrumental delivery failed. Our study is the first to demonstrate that there is a high chance of success in a trial of labour, even if a trial of instrumental vaginal delivery by vacuum or forceps at the previous delivery failed and was followed by caesarean section. One study15 has reported that failed instrumental delivery performed as a trial of vacuum followed by caesarean section was not associated with increased fetal morbidity.

Our study showed a reduced success rate of trial labour with progressive birthweight, as reported before10,14. Where trial of labour resulted in vaginal birth, there was an increased chance of instrumental vaginal delivery with a higher birthweight.

Acknowledgement

We are grateful to Dr H. M. Koning for help in statistical analysis.

References

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. METHODS
  5. RESULTS
  6. DISCUSSION
  7. References