Objectives To assess the proportion of breech presentations diagnosed
in labour and to compare their outcomes with those diagnosed prior to
the onset of labour. Design Retrospective casenote review. Setting Mil
l Road Maternity Hospital, a teaching hospital in central Liverpool. S
ubjects Three hundred and five singleton breech presentations delivere
d in the hospital between January 1988 and July 1991; 226 cases prior
to the onset of labour and 79 cases diagnosed for the first time in la
bour. Main outcome measures Rates of vaginal delivery and caesarean se
ction, birthweight, short term morbidity as assessed by trauma, signs
of cerebral irritation and admission to the newborn intensive care uni
t (NBICU), and Apgar scores. Results Breech presentations diagnosed fo
r the first time in labour were more likely to deliver vaginally than
those assessed and allowed to go into labour (odds ratio 1:68 95% CI 1
.0-3.0). This difference was not due to demographic variables or diffe
rences in birthweight. There was no short term morbidity attributable
to vaginal breech delivery. Conclusion A significant number of breech
presentations are not detected until labour despite rigorous antenatal
surveillance. Our results show that undiagnosed breeches may not be i
mportant as they are more likely to deliver vaginally, with no excess
morbidity or mortality, compared to diagnosed breeches in labour, care
fully assessed for vaginal delivery. There are, therefore, no grounds
for delivering all undiagnosed breeches by caesarean section.