ArticlesEarly maternal and neonatal morbidity associated with operative delivery in second stage of labour: a cohort study
Introduction
The rising rate of caesarean section worldwide has been widely debated. Issues relating to maternal choice,1, 2 mode of delivery for breech presentation at term,3 and vaginal birth after caesarean section4 have been emphasised, and much debate has focused on subsequent morbidity. Vaginal instrumental delivery and caesarean section account for up to 25% of all deliveries in British maternity units5 and we believe that these deliveries should receive greater attention. For many women, caesarean section is not planned or even considered, and it is especially disappointing when caesarean section is the outcome of a long and difficult second stage of labour. The dilemma obstetricians frequently encounter is how to keep maternal and neonatal morbidity to a minimum when given a choice between difficult vaginal instrumental delivery and caesarean section, at full dilatation.
In the changing childbirth report6 the authors emphasised the importance of patient choice when decisions need to be made about the management of pregnancy and childbirth. We believe that women should be able to make an informed choice on the basis of the best available evidence rather than on the opinion of the obstetrician alone. At present we have little high quality evidence on which to base decisions in relation to difficult delivery in the second stage of labour. There have been inconsistent reports of early maternal and neonatal morbidity after vaginal instrumental delivery compared with caesarean section for midcavity arrest.7, 8, 9, 10, 11, 12 This inconsistency might be related to the retrospective design of such studies and the methodological biases inherent in them.
Rates of operative delivery vary strikingly between UK regions, which cannot be wholly explained by mix of cases.5 Such wide variation in obstetric practice is due to the scarcity of published data about the outcome of operative delivery and the wide range of opinion about the best mode of delivery. This situation seems to present the perfect setting for a randomised trial. However, as Penn and colleagues13 found, when obstetricians have strong views on appropriate management, randomised trials will probably fail because insufficient numbers of patients would be willing to participate. Furthermore, to randomise women to caesarean section or vaginal instrumental delivery in the second stage of labour is neither feasible nor ethical,14 and recruitment will probably be difficult in the antenatal period. We have to rely, therefore, on high-quality observational studies to make decisions.
Our aim was to investigate maternal and fetal morbidity after vaginal instrumental delivery in theatre and caesarean section, at full cervical dilatation, in a complete geographical cohort of women with obstructed labour.
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Participants
Between February, 1999, and January, 2000, we identified all women at St Michael's Hospital and Southmead Hospital, Bristol, who were fully dilated and needed vaginal instrumental delivery in theatre or caesarean section. Women were followed up prospectively until discharge from hospital. Both study centres are teaching hospitals that have a combined total of 1010 000 deliveries a year. Obstetricians with varying levels of skill rotate between the two hospitals. Additionally, women are
Characteristics
393 women from a cohort of 10·106 deliveries required operative delivery in theatre during the year of the study. No woman declined to participate in the study. Caesarean section was done in 209 cases (21 per 1000 deliveries) and vaginal instrumental delivery was successful in 184 cases (18 per 1000 deliveries), which consisted of 63% of the total 291 attempts at vaginal instrumental delivery. Immediate caesarean section without attempted vaginal delivery was done in 102 cases (26%). Caesarean
Discussion
We compared caesarean section delivery at full dilatation with vaginal instrumental delivery and noted a higher rate of maternal morbidity after caesarean section delivery, which is shown by extended postnatal admission. Caesarean section delivery was associated with increased neonatal admission to the SCBU but with reduced neonatal trauma.
The higher rate of maternal morbidity reported after caesarean section is consistent with those in other studies, particularly in relation to blood loss and
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