What is the prevalence of vaginal laceration (vaginal tear) after vaginal birth for each degree of perineal trauma?

From the Guidelines

The prevalence of vaginal tears after vaginal birth varies by degree, with first-degree tears occurring in approximately 5.5% to 16.4% of births, second-degree tears in 29.0% to 35.1%, third-degree tears in 1.8% to 7.1%, and fourth-degree tears in 0% to 0.3% of births, as reported in a prospective study conducted in the United Kingdom 1.

Prevalence Rates

The prevalence rates of perineal lacerations can vary based on factors such as maternal age, baby size, use of instruments during delivery, episiotomy practices, and delivery position.

• First-degree tears: 5.5% to 16.4% of births
• Second-degree tears: 29.0% to 35.1% of births
• Third-degree tears: 1.8% to 7.1% of births
• Fourth-degree tears: 0% to 0.3% of births

Risk Factors

Risk factors for vaginal tears include first vaginal delivery, large babies (over 4kg), instrumental deliveries (forceps or vacuum), prolonged second stage of labor, and occiput posterior position of the baby 1.

Preventive Measures

Preventive measures include perineal massage during pregnancy, warm compresses during labor, controlled pushing during delivery, and appropriate support of the perineum by the birth attendant.

Repair and Postpartum Care

Proper repair and postpartum care are essential for healing and preventing long-term complications, with techniques such as end-to-end or overlapping repair of the internal anal sphincter (IAS) and external anal sphincter (EAS) recommended 1.

From the Research

Prevalence of Vaginal Tears After Vaginal Birth

• The prevalence of vaginal tears after vaginal birth is significant, with more than 85% of women experiencing some form of perineal trauma 2.
• Spontaneous tears requiring suturing are estimated to occur in at least one third of women in the UK and US 2.
• The prevalence of third- and fourth-degree perineal tears is particularly concerning, with Australian women experiencing higher rates compared to countries of similar economic development 3.

Degree of Vaginal Tears

• First-degree perineal tears are the most common type of tear, and surgical glue has been shown to be an effective alternative to sutures for repairing these tears, resulting in less perineal pain and faster repair 4.
• Second-degree perineal tears can be repaired using a continuous suture or an interrupted suture, with the former being recommended for reducing pain 5.
• Third- and fourth-degree perineal tears are associated with significant pain, discomfort, and long-term implications for women's health and quality of life 6, 3.
• The management of third- and fourth-degree perineal tears requires careful inspection, palpation, and surgical repair by a specialist physician, with the aim of reducing immediate and long-term damage 6.

Risk Factors for Vaginal Tears

• Risk factors for third- and fourth-degree perineal tears include primiparity, mother's ethnicity, large for gestational age infants, and certain interventions used in labor and birth, such as instrumental deliveries 3.
• Preventive practices, such as antenatal perineal massage, different maternal birthing positions, water births, warm compresses, protection of the perineum, and episiotomy for instrumental births, can reduce the risk of severe perineal tears 3.