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

  • Third and fourth degree tears were more common in vaginal first births (around 5%) than subsequent vaginal births (around 3%) across all years between 2013 and 2020.
  • Women in the 25 to 29 age group were most likely to experience a third of fourth degree tear than women in other age-groups for first and subsequent vaginal births.
  • Third and fourth degree tears were more frequent in public hospitals compared to private hospitals.

The interactive data visualisation below presents data on third and fourth degree tears for all vaginal births and all vaginal first births by selected maternal characteristics. Click the Data tables button to view the data between 2013 and 2020 and use the radio buttons to see how each characteristic has changed during this time.

Third and fourth degree tears for all vaginal first births, by State/territory of birth and all Australia, 2013 to 2020.

This chart shows the proportion of third and fourth degree tears in mothers for all vaginal first births, by state/territory of birth, 2013 to 2020.  Data can be viewed for each state/territory of birth, and for all Australia. 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 4.8% in 2020. The chart also includes an option to display 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 steady with 3.0% in 2013 and 2.9% in 2020.

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). 

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 & 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 the Data tab.

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