Undiagnosed breech revisited

Objectives To study the incidence of undiagnosed breech and to compare the obstetric outcome with those diagnosed before the onset of labour in a loca l teaching hospital where external cephalic version at term is routinely of fered. Design A retrospective casenote analysis. Setting Tsan Yuk Hospital, a reaching hospital in Hong Kong. Participants One hundred and thirty-one women with a singleton breech prese ntation at term, delivered in a local teaching hospital from 1 January 1997 to 31 December 1997. The group of 22 women who had successful external cep halic version performed was included. Results Breech presentation was diagnosed at: the antenatal clinic in 103 w omen (79%). In the remaining 28 women (21%), breech presentation was diagno sed for the first time after the onset of labour. Undiagnosed breech presen tations were more likely to deliver vaginally (42%) than those diagnosed at the antenatal clinic (11%) (P < 0.001). Vaginal delivery was still more co mmon in the undiagnosed group (46%) than the diagnosed group (26%), even wh en the group with successful external cephalic version was included (P < 0. 05), although the difference became less obvious. The demographic character istics, birthweight, type of breech and short term neonatal outcomes were c omparable between the two groups. Conclusion It is important to include women who had successful external cep halic version when comparing the obstetric outcome of undiagnosed and diagn osed breeches. Careful assessment for vaginal delivery is still very useful even when breech presentations are first diagnosed after the onset of labo ur because the infants are even more likely to deliver vaginally with no gr eat excess of neonatal morbidity.