Birth injury and perineal recovery

Most vaginal births involve some perineal trauma. Understanding the grade, the expected healing course and the treatable causes of ongoing pain prevents years of avoidable discomfort.

Grades of tear

Obstetric anal sphincter injury (OASI, third and fourth degree combined) occurs in about 2.9% of vaginal births in the UK overall, and around 6% of first vaginal births (RCOG Green-top Guideline 29). Risk factors include first vaginal birth, birthweight over 4 kg, occipito-posterior position, prolonged second stage and forceps delivery.

The OASI Care Bundle (RCOG/RCM, evaluated 2020) — including manual perineal protection and mediolateral episiotomy where indicated — was associated with a reduction in OASI rates from 3.3% to 3.0% across participating units. Warm compresses and perineal massage in the second stage have Cochrane-supported evidence for reducing severe tears.

Healing timeline

• Skin closure typically 2–3 weeks; sutures usually dissolve within 4–6 weeks.
• Deeper muscle healing and remodelling continues for 3–6 months.
• After caesarean, the uterine scar is largely healed at 6 weeks but abdominal wall sensitivity and scar numbness often persist 6–12 months.

Sex after birth

• The "six-week rule" is a convention, not a physiological deadline. Guidance from RCOG and ACOG is to wait until bleeding has stopped, any repair has healed, and the person feels ready — which for many is later than six weeks.
• Timing data: the Australian MatCHS cohort (McDonald & Brown, BJOG, 2013) found 41% had resumed vaginal sex by 6 weeks, 78% by 3 months and 94% by 6 months.
• Pain data is the important part. In the same cohort, 85% reported pain at first postpartum vaginal sex, falling to about 45% at 3 months and 24% at 6 months. Persistent dyspareunia at 18 months affected around 1 in 4 in some cohorts, and was strongly predicted by OASI, assisted delivery, and — independently — by exclusive breastfeeding.
• Breastfeeding lowers oestrogen, which thins vaginal tissue and reduces lubrication. This is physiological, not a failure of desire. Generous water- or oil-based lubricant is the first step; vaginal oestrogen is safe during breastfeeding and is prescribed when lubricant is not enough.

What helps

• Pelvic floor muscle training, ideally supervised — Cochrane evidence supports it for postpartum incontinence and it is associated with improved sexual function scores.
• Scar massage once fully healed (from around 6 weeks), for perineal and caesarean scars.
• Positions that let the receiving partner control depth and angle, and non-penetrative intimacy while healing.
• Treating constipation early; straining stresses a repaired perineum.

Red flags — see a clinician

• Pain at the same spot every time, or a tight band of scar tissue — often a treatable granulation or over-tight repair, not something to live with.
• Any new incontinence of urine, wind or stool; any urgency you cannot defer. OASI carries a real risk of anal incontinence and specialist perineal clinics exist for this.
• Wound gaping, offensive discharge, fever — signs of infection or breakdown.
• A dragging or bulging sensation, which may indicate prolapse.
• Persistent low mood or intrusive thoughts about the birth: birth trauma and PTSD are common and treatable (see perinatal mood and intimacy).

Ongoing pain after 6 months should always be assessed. It is not "just how it is now".

Sources

• RCOG, Green-top Guideline No. 29, The Management of Third- and Fourth-Degree Perineal Tears, 2015.
• RCOG/RCM OASI Care Bundle evaluation, 2020.
• McDonald EA & Brown SJ, BJOG, 2013 (resumption of sex and dyspareunia after birth).
• Aasheim V et al., Cochrane Database of Systematic Reviews, 2017 (perineal techniques in second stage).
• ACOG Committee Opinion 736, Optimizing Postpartum Care, 2018.