Instrumental vaginal delivery
A meta-analysis of two studies found that IVD was associated with a higher PTSD score than SVD (appendix S5) , again consistent with the NMA findings. The small-to-medium difference (ES=0.38) was strongly statistically significant (p<0.001).
Two studies subdivided instrumental vaginal deliveries into forceps and ventouse deliveries . Creedy et al. found an association between forceps and ventouse deliveries and PTSD symptoms . In contrast to this, Lyons found no significant relationship between PTSD symptoms and mode of delivery .
Five of the other studies combined instrumental vaginal births into one variable. Furuta et al. found PTSD symptoms were more common with IVD than SVD. Dekel et al. found greater PTSD symptoms in IVD than in SVD and their separate category of natural VD (without anaesthesia) . Ryding et al. did not directly compare IVD and SVD, but found no significant difference between PTSD symptoms in those who had IVD and those who had EmCS, which they found to be more related to PTSD than both ElCS and SVD. Cohen et al. found no significant differences between IVD, SVD and CS, Polachek et al. did not find an association with any mode of birth and PTSD and Vossbeck-Elsebuschet al. found no statistically significant association between IVD and PTSD.