TIME TRENDS IN EPISIOTOMY AND SEVERE PERINEAL TEARS IN PORTUGAL: A
NATIONWIDE REGISTER-BASED STUDY
Abstract
Objective: To estimate time trends in the frequency of severe perineal
tears (SPT) in Portugal and its relationship with episiotomy. Design:
Nationwide register-based study by using the national inpatient
database. Setting: All Portuguese public hospitals Population: All women
with a singleton vaginal delivery between 2000 and 2015 Methods:
Time-trend analysis using joinpoint regression models was performed to
identify time trends in the prevalence of SPT and of risk factors,
including episiotomy. Poisson regression models were fitted to assess
the association between episiotomy and SPT. Main Outcome Measures:
Annual percentage change (APC) with 95% Confidence Interval (95% CI)
in the prevalence of SPT and its risk factors. Adjusted relative risk
(RR) and respective 95% CI. Results: From 908,889 singleton vaginal
deliveries, 20.6% were instrumental deliveries, 76.7% with episiotomy
and 0.56% were complicated by SPT. SPT decreased among women with
non-instrumental deliveries and no episiotomy from 2009 onwards (1.3%
to 0.7%), whereas SPT kept increasing in women with episiotomy for both
non-instrumental (0.1% in 2000 to 0.4% in 2015) and instrumental
deliveries (0.7% in 2005 to 2.3% in 2015). Episiotomy was associated
with a decrease in SPT with adjusted RR varying between 2000 and 2015
from 0.18 (95%CI:0.13-0.25) to 0.59 (95%CI:0.44-0.79) for
non-instrumental deliveries and from 0.45 (95%CI:0.25-0.81) to 0.50
(95%CI:0.40-0.72) for instrumental deliveries. Conclusions: Episiotomy
rate could safely further decrease as the main factor driving SPT rates
seems to be an increase in awareness and reporting of SPT particularly
among women who underwent an episiotomy.