[Association of Birth Trauma with the Implementation of Obstetrical Monitoring Tools: A Retrospective Cohort Study]

Lacerations are common in vaginal births. They can result in immense physical and psychological morbidity. Ongoing efforts are being made to reduce birth trauma. We implemented different obstetrical monitoring tools in the labor ward and evaluated their association with the incidence and distribution of different types of birth lacerations.

We retrospectively analyzed nulliparous and multiparous women with singleton term pregnancies in vertex presentation, who gave birth vaginally in our tertiary care center between October 2014 and September 2015. We evaluated 3 different time intervals (T1=4 months before the implementation of the monitoring tools, T2=0-4 months and T3=5-8 months afterwards). Outcome parameters were the incidence and distribution of different types of birth lacerations during the 3 different time intervals.

The incidence of all types of birth trauma decreased from 95,52% in nulliparous and 68,53% in multiparous women at T1 to 89,92% and 62,27% non-significantly at T3, with a decrease in perineal and vulvar/labial lacerations and an increase in vaginal lacerations. The rate of episiotomies and third-/fourth-degree perineal tears remained stable for nulliparous (33 and 3%) and multiparous (10 and 0.4%) women between the time intervals.

The overall incidence of birth lacerations is high, with lacerations predominantly appearing as first- and second-degree perineal tears but also vaginal and labial lacerations. The initiation of different obstetrical monitoring tools is associated with a change in the incidence of birth traumas and a shift from an external to an internal distribution, probably due to more careful management by the obstetrical staff. The implementation of such tools might help to improve obstetrical management and laboring women might benefit. However, it is important to realize the effect of monitoring and observation itself on the course of observational studies.