Evaluation of a Quality Improvement Intervention to Increase Vaginal Birth for Twins

To evaluate whether there was an association between the systematic promotion of twin vaginal delivery and an increase in the rates of twin vaginal birth.

We conducted a retrospective cohort study. We implemented a quality improvement initiative promoting twin vaginal delivery at an academic tertiary care center in 2013. The program included a needs assessment, simulation of vaginal twin delivery, online educational material, and the expansion of a dedicated twin clinic. We analyzed rates of twin vaginal birth in pregnancies at or beyond 24 weeks of gestation without a contraindication to labor, prior uterine surgery, or a demise or lethal anomaly of either twin. Using linear regression, we calculated annual adjusted rates of twin vaginal birth from 2010 to 2015 and in the 3 years before and after our intervention. We performed an interrupted time-series analysis estimating rates of change before and after the intervention to account for the influence of secular trend.

Of 1,574 patients delivering twins, 897 (57%) were included, with 479 in the 3 years before and 418 in the 3 years after the intervention. Adjusted rates of vaginal delivery increased from 32.1% (n=153) to 44.2% (n=185) before and after the intervention (P<.01), with a decrease in elective cesarean delivery from 54.6% (n=479) to 44.3% (n=185) (P<.01). Rates of breech extraction increased after the intervention (5.7% vs 9.3%, P=.04). However, there was no difference in the rate of change in twin vaginal birth in the time period before (1.35% annual increase, P=.76) or after (5.8% annual increase, P=.40) the intervention.

Although we observed an increased rate of twin vaginal birth in the time period after our intervention, because the rates of increase before and after the intervention were not statistically different, the increase is not attributable to our intervention and is more properly attributed to secular trend.