Instrumental vaginal birth

Selected women

Selected women include those aged between 20 and 34 years, whose baby’s gestational age at birth was between 37 and 41 completed weeks, with a singleton baby in the vertex presentation.

Comparison of ‘selected’ groups of women allows for an indication of standard practice. Selected women, for this indicator, refers to a cohort of mothers who are expected to have reduced labour complications and better birth outcomes. The proportion of selected women is approximately one-third of all women who gave birth in 2016.

Clinical commentary

The use of instruments – vacuum extraction cup or forceps – may be required to achieve a safe vaginal birth. Using instruments to assist birth is usually recommended when the condition of either the baby or the mother makes it less safe to allow time for normal birth to occur (RANZCOG 2016).

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 2016). Both vacuum and forceps assisted delivery are associated with an increased risk of injury to the tissues of the vagina, perineum and anus, which may lead to long-term perineal pain and sexual difficulties; additionally, a very small number may have urinary or faecal incontinence (RANZCOG 2016; RCOG 2011). Specialist obstetric and women’s healthcare groups recommend that episiotomy is used selectively, rather than routinely, in association with vacuum and forceps assistance to minimise that risk (RANZCOG 2016; RCOG 2011; WHA 2017).

Although the overall rate of injury to the baby as a result 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 2011). 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.

Indicator specifications and data

Excel source data tables are available from the Data tab.

For more information refer to Specifications and notes for analysis in the technical notes.