Site and incidence of birth canal lacerations from instrumental delivery with mediolateral episiotomy.

OBJECTIVE

Instrument-assisted vaginal delivery is a significant risk factor for birth canal lacerations. Although many obstetricians recently are recommending restrictive rather than a routine episiotomy, reports have shown restrictive episiotomy to be associated with more extensive anterior birth canal trauma compared with routine episiotomy.

MATERIALS AND

METHODS

We retrospectively reviewed 110 cases of forceps and vacuum deliveries and investigated the site of birth canal lacerations. Birth canal lacerations were divided into four sites according to direction-anterior, ipsilateral, contralateral, and posterior.

RESULTS

The frequency of lacerations were, from most to least, posterior (34%), lateral (21.7%), and anterior (1.9%). Moreover, among the lateral lacerations, they were more frequent in the contralateral side of episiotomy than the ipsilateral side (18.9% vs. 4.7%, p < 0.01).

CONCLUSION

Our results indicate that caution is also needed concerning not only the anterior site, but also the contralateral site of an episiotomy to prevent laceration in an instrument-assisted vaginal delivery.