Study: Vulvar Lichen Sclerosus Increases Risk of Perineal Tears
Women diagnosed with vulvar lichen sclerosus face a significantly higher risk of sustaining severe perineal tears during vaginal delivery, according to a retrospective cohort study published online on October 7 in the American Journal of Obstetrics and Gynecology.
- Vulvar lichen sclerosus increases the relative risk of second-degree perineal tears by 1.32 to 1.37 times during vaginal birth.
- The condition elevates the risk of obstetric anal sphincter injuries by more than threefold compared to unaffected patients.
- Key risk factors for severe tearing within this patient group include nulliparity, vacuum-assisted delivery, and an already narrowed vaginal introitus.
Retrospective Cohort Findings Across North Denmark Region Births
Led by Cecilie Hagen Andersen of North Denmark Regional Hospital in Hjørring, Denmark, researchers evaluated medical birth records from the North Denmark Region spanning October 1, 2019, to September 30, 2024. The study analyzed 224 vaginal births among women diagnosed with vulvar lichen sclerosus, comparing them against 441 births from women without the condition. Meanwhile, a slightly broader count of 277 medical birth records for the vulvar lichen sclerosus group and 533 controls was noted in data extraction. Among the vaginal births evaluated in the vulvar lichen sclerosus group, 12 involved obstetric anal sphincter injuries.
Adjusted Risk Multipliers for Perineal Trauma
After adjusting for relevant maternal and obstetric factors such as parity, birth weight, head circumference, and vacuum assistance, statistical models revealed stark contrasts in delivery outcomes. Women with vulvar lichen sclerosus carried a 1.32-fold higher risk for second-degree perineal tears and a 3.37-fold higher risk for obstetric anal sphincter injury compared to unaffected controls, with p-values of .006 and .01, respectively. A nearly identical relative risk of 1.37 for second-degree tears and the same 3.37-fold elevated risk for sphincter injuries was recorded.
Specific Risk Factors During Labor and Pregnancy
Within the cohort of women with vulvar lichen sclerosus, investigators identified distinct variables that compounded the likelihood of severe perineal damage. First-time mothers faced a 4.91-fold increase in risk, while vacuum-assisted deliveries heightened the hazard by 6.50-fold. Anatomical narrowing of the vaginal opening before pregnancy raised the risk of obstetric anal sphincter injury by 6.20-fold, and active symptoms during pregnancy—such as persistent itching or skin fragility—added a 3.98-fold increase. The duration of the second stage of labor showed a minor association with elevated injury risk.
Clinical Management and Disease Control Before Delivery
Authors of the study emphasized that proper disease management remains vital for mitigating physical trauma during childbirth. “[The] study emphasizes the importance of adequate and continuous treatment of VLS both before and throughout pregnancy as disease control may help reduce the risk of obstetric perineal trauma,” the researchers wrote. Because vulvar lichen sclerosus is a chronic inflammatory skin disease that compromises tissue integrity in the anogenital region, maintaining skin elasticity through clinical interventions is standard practice, though retrospective limitations meant prior treatment controls could not be fully verified.
Disclaimer: The information provided in this article is for educational and scientific communication purposes only and does not constitute medical advice.