Instrumental delivery is employed to accelerate birth in the presence of suspected or anticipated fetal compromise, delay in the second stage of labour or when maternal pushing efforts may make blood pressure or heart problems worse (RANZCOG 2020). Both vacuum and forceps assisted delivery are associated with an increased risk of injury to the tissues of the vagina, perineum and anus. This may lead to long-term perineal pain and sexual difficulties; additionally, a very small number may have urinary or faecal incontinence (RANZCOG 2020; RCOG 2020). Specialist colleges of obstetrics and gynaecology recommend that episiotomy is used selectively, rather than routinely, in association with vacuum and forceps assistance to minimise that risk (RANZCOG 2020; RCOG 2020).
Although the overall rate of injury to the baby because of instrumental vaginal delivery is low, there is a risk of certain complications, including injuries to the baby’s scalp, head, and eyes; bleeding inside the skull; and problems with the nerves located in the arm and face (RCOG 2020). The choice of which instrument to use depends on the clinical situation, and the principles of informed consent require that the woman is provided with information regarding these risks and the proposed benefits of the procedure prior to embarking on assisted vaginal birth.