Is the policy of restrictive episiotomy generalisable? A prospective observational study.

Objective: To assess whether the policy of restrictive episiotomy could be safely implemented in Chinese population, and whether perineal length was related to risk of perineal tear during spontaneous vaginal delivery.

Methods: A prospective observational study was conducted between November 2007 and February 2008. A restrictive approach of episiotomy was implemented in those Chinese women who carried an uncomplicated singleton cephalic presenting pregnancy in labour. Perineal length (PL) was measured at three time points: (A) at early first stage of labour; (B) at the beginning of the second stage; (C) at crowning. Women with and without perineal tears were compared with reference to PL measured at different stages and its stretching performance (defined by the change in PL between different stages).

Results: Among the 429 women recruited, mean PL at point A, B and C was 38.8 mm (+/-7.9), 49.4 mm (+/-8.1) and 59.4 mm (+/-9.4), respectively, which were similar to those reported in other countries. Episiotomy rate reduced from 73.3 to 26.8%. Among the non-episiotomy group, 13.7% had no perineal tear, 86.3% had minor (first or second degree) tears but none had major tears, whilst 3.5% and 0.9% of episiotomy group had minor and major tears, respectively. PL was not associated with the risk of perineal tear.

Conclusions: Restrictive episiotomy reduces the episiotomy rate without compromising the perineal safety. Chinese women's PL is not shorter than other races, or is predictive of perineal tears.