Third and fourth degree tears

A perineal tear is the laceration of the skin and tissues that separate the vagina from the anus. Third or fourth degree tears are classified as severe trauma to the perineum and can occur spontaneously or as a result of obstetric intervention during vaginal birth. For more information, see Clinical commentary.

This indicator looks at the proportion of third and fourth degree tears among all women who gave birth vaginally, and among all vaginal first births.

Key findings

In 2021:

  • 4.5% of women giving birth for the first time and giving birth vaginally experienced a third or fourth degree tear
  • 2.7% of all women giving birth vaginally experienced a third or fourth degree tear.

The proportion of third and fourth degree tears among women giving birth vaginally:

  • has fluctuated around 5% between 2013 (5.2%) and 2021 (4.5%) for vaginal first births, and has remained fairly stable for all vaginal births during this time (3.0% in 2013 and 2.7% in 2021)
  • was higher for women giving birth in public hospitals than private hospitals (5.0% compared with 2.5% for all vaginal first births in 2021)
  • was highest in women aged 25–29 (3.1% in 2021) and lowest in women aged 40 and over (1.7% in 2021) for all vaginal births.

The interactive data visualisation (Figure 15) presents data on third and fourth degree tears for all vaginal births and all vaginal first births by selected maternal characteristics. Select the trend button to see how data have changed between 2013 and 2021.

Figure 15: Third and fourth degree tears

Third and fourth degree tears for all vaginal first births, 2013 to 2021.

This chart shows the proportion of third and fourth degree tears for all vaginal first births, for the current data 2021 and trend data from 2013 to 2021. The proportion of third and fourth degree tears for all vaginal first births, for all Australia, has fluctuated around 5% with 5.2% in 2013 and 4.5% in 2021. The chart also shows data for third and fourth degree tears for all vaginal births. The proportion of third and fourth degree tears for all vaginal births, in Australia, has remained fairly stable with 3.0% in 2013 and 2.7% in 2021.

Clinical commentary

Severe perineal trauma is defined as a third degree tear, which involves injury to the perineum which extends to the anal sphincter muscles; or a fourth degree tear, which involves injury to the perineum involving the external and internal sphincter and the anorectal epithelium (RCOG 2015). Severe trauma to the perineum can occur spontaneously or due to obstetric intervention during vaginal birth.

Severe perineal trauma is associated with maternal morbidity such as perineal pain, incontinence and subsequent difficult or painful sexual intercourse, and rarely, recto-vaginal fistula (RCOG 2015; ACSQHC 2021). The significant psychological effects of severe perineal trauma are under-researched but likely to be significant for many women in this situation (Priddis et al. 2013). While it may not always be possible to prevent these types of tears, the likelihood can be reduced through appropriate labour management and high-quality obstetric care (ACSQHC 2021, OECD 2021). Internationally, Australia's rate of third and fourth degree tears was higher than the average for OECD countries in 2019 or nearest year (OECD 2021). Variation between countries is likely to be affected by differences in clinical practice and reporting (ACSQHC 2018).

Risk factors during the antenatal period associated with an increased incidence of severe perineal trauma include nulliparity, young maternal age, ethnicity and poor nutritional status, high fetal weight, as well as previous experience of perineal tear (Dahlen et al. 2013). Intrapartum risk factors include fetal malpresentation (for example occipito-posterior position), episiotomy (especially midline), instrumental vaginal birth, prolonged second stage of labour, birth position and shoulder dystocia (Eskandar and Shet 2009; Hartman et al. 2005; Kudish et al. 2008; O'Mahony et al. 2010).

Indicator specifications and data

Excel source data tables are available from Data.

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