- Design
- Retrospective matched cohort, single Danish region
- Population
- 277 births to women with vulvar lichen sclerosus, 533 control births
- Primary outcome
- Second-degree tears and obstetric anal sphincter injury
- Effect
- Second-degree tear RR 1.37 (1.14-1.65); sphincter injury RR 3.37 (1.30-8.76)
A Danish regional cohort (AJOG, 7 October 2026) compared 277 births to women with diagnosed vulvar lichen sclerosus against 533 matched control births between 2019 and 2024.
After adjustment for parity, birth weight, head circumference and vacuum delivery, lichen sclerosus was associated with more second-degree tears (RR 1.37, 95% CI 1.14-1.65) and more obstetric anal sphincter injuries (RR 3.37, 1.30-8.76). Within the lichen sclerosus group, sphincter injury was associated with nulliparity, vacuum delivery, a narrowed introitus and symptoms during pregnancy.
Lichen sclerosus is often thought of as a postmenopausal problem, so it may not be asked about at booking. This study suggests it is worth knowing about before the second stage, when it can shape counselling, positioning and the threshold for assisted delivery. The design is retrospective and the sphincter-injury estimates are imprecise, so these are associations to act on with judgement rather than a basis for routine caesarean.
- Ask about vulvar lichen sclerosus at booking, and examine where symptoms suggest it
- Flag a narrowed introitus or active symptoms in pregnancy in the birth plan
- Consider optimising disease control with topical steroid before term in symptomatic women
- Take extra care with perineal protection and with the decision for vacuum delivery
- Examine carefully for sphincter injury after birth in affected women
Why it matters
A condition rarely asked about at booking may mark women who need a different second-stage plan.
Don't overread it
A retrospective association with few events - it does not justify planned caesarean for lichen sclerosus.
The statistics, in plain English
A relative risk of 3.37 means sphincter injury was about three times as common, but the interval (1.30-8.76) is wide because events were few: the true increase could be modest or very large. The within-group risk factors came from bivariate analyses of a small group, so treat them as pointers.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for obstetrics & gynaecology, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free