National Core Maternity Indicators: PI 13–Third and fourth degree tears for vaginal births, 2022

Collection and usage attributes

(a) The number of females who had a third or fourth degree perineal laceration after giving birth for the first time and birth vaginally, divided by the number of females who gave birth for the first time and birth vaginally, and multiplied by 100.

(b) The number of females who had a third or fourth degree perineal laceration after giving birth vaginally, divided by the number of females who gave birth vaginally, and multiplied by 100.

A birth is defined as the complete expulsion or extraction from a female, of a product of conception of 20 or more completed weeks of gestation or of 400 grams or more birthweight.

Births included are vaginal births, including non-instrumental and instrumental births. A non-instrumental vaginal birth is one in which the baby is born through the vagina without the assistance of instruments. An instrumental birth is a procedure that uses instruments (forceps or vacuum extraction) to assist the baby to come out through the vagina.

Births excluded are caesarean sections.

Third degree laceration is defined as perineal laceration, rupture or tear occurring during delivery, involving: anal sphincter, rectovaginal septum, and sphincter not otherwise specified. Excludes laceration involving the anal or rectal mucosa. Fourth degree laceration is defined as perineal laceration, rupture or tear as in third degree laceration occurring during delivery, also involving: anal mucosa and rectal mucosa.

100 × (Numerator ÷ Denominator)

(a) The number of females who had a third or fourth degree perineal laceration after giving birth for the first time and birth vaginally.

(b) The number of females who had a third or fourth degree perineal laceration after giving birth vaginally.

(a) The number of females who gave birth for the first time and birth vaginally.

(b) The number of females who gave birth vaginally.

• Year of birth
• State or territory of birth
• Mother's age at birth
• Hospital annual number of births
• Hospital sector
• Remoteness category (from mother's area of usual residence)
• Indigenous status of mother
• With and without episiotomy
• Mother's country of birth
• Primary Health Network (from mother's area of usual residence)
• Statistical local area 3 (from mother's area of usual residence)

Data elements are from the Perinatal National Minimum Data Set (NMDS) or have been provided as voluntary non-standardised items by states and territories. Records with a permissible value have been included in the denominator.

For the 2013 analysis, third and fourth degree tears was calculated using Labour complication: third/fourth degree data item. A revised collection of perineal status data items in the Perinatal NMDS was introduced in 2014, which meant that the perineal status was split between seven perineal status data items. As a result, for 2014 onwards analysis, third and fourth degree tears was calculated using two data items, Perineal status: third degree laceration (code 4) and Perineal status: fourth degree laceration (code 7).

Modified from Australian Council on Healthcare Standards (ACHS) Indicator 3.1-3.6: Major perineal tears and surgical repair of the perineum. This ACHS indicator is based on the definition by Women's Healthcare Australasia Core Maternity Indicators Project (WHA 2007).

Representational attributes

N[NN.N]

Data source attributes

Accountability attributes

No formal reporting requirements

Australian Institute of Health and Welfare

Australian Institute of Health and Welfare

Source and reference attributes

ACHS (The Australian Council on Healthcare Standards) 2021. The Australasian Clinical Indicator Report: 2013-2020. 22nd edn. Sydney: ACHS. Viewed 08 April 2022, https://www.achs.org.au/our-services/pos/previous-acir-publications.

WHA (Women's Healthcare Australasia) 2007. Supporting excellence in maternity care: the core maternity indicators project: findings from the core maternity indicators project. Canberra: WHA.

Relational attributes