Factors related to genital tract trauma in normal spontaneous vaginal births

Episiotomy rates are declining in the United States. In settings with very low rates, evidence remains sparse on how best to facilitate birth without lacerations. The purpose of this investigation was to identify maternal and clinical factors related to genital tract trauma in normal, spontaneous vaginal births.

Data from a randomized clinical trial of perineal management techniques were used to address the study objective. Healthy women had spontaneous births with certified nurse-midwives in a medical center setting. Proportions of maternal characteristics and intrapartum variables were compared in women who did and did not sustain sufficient trauma to warrant suturing, according to parity (first vaginal births versus others). Logistic regression using a backward elimination strategy was used to identify predictors of obstetric trauma.

In women who had a first vaginal birth, risk factors for trauma were maternal education of high school or beyond, Valsalva pushing, and infant birthweight. Risk factors in women having a second or higher vaginal birth were prior sutured trauma and infant birthweight. For all mothers, delivery of the infant's head between contractions was associated with reduced trauma to the genital tract.

Delivery technique that is unrushed and controlled may help reduce obstetric trauma in normal, spontaneous vaginal births.