In a pregnant woman with high‑grade cervical intra‑epithelial neoplasia (CIN 2‑3), what is the miscarriage risk of a Loop Electrosurgical Excision Procedure (LEEP) and the safest timing for the procedure?

LEEP Procedure and Miscarriage Risk in Pregnancy

LEEP should not be performed during pregnancy for CIN 2-3 unless invasive cancer is suspected or confirmed—this is the only indication for cervical excisional procedures in pregnant women. 1, 2

Critical Management Principle for Pregnant Women with CIN 2-3

Defer all treatment until postpartum. The risk of progression from CIN 2-3 to invasive cervical cancer during pregnancy is minimal, and the rate of spontaneous regression postpartum is relatively high (69% in one study). 1, 3

Why LEEP is Contraindicated During Pregnancy

• Excisional procedures during pregnancy are associated with significant bleeding and preterm births. 1
• High rate of recurrent/persistent disease: 47% of pregnant women undergoing LEEP had residual CIN identified postpartum, making the procedure frequently nondiagnostic. 1
• Complications outweigh benefits: The procedures are associated with complications and high recurrence rates that do not justify the intervention given the low cancer progression risk during pregnancy. 1

Appropriate Management Algorithm for Pregnant Women with CIN 2-3

Step 1: Initial Evaluation

• Perform colposcopy by a clinician experienced in pregnancy-induced colposcopic changes. 4, 2
• Biopsy only lesions suspicious for CIN 2-3 or cancer (preferred approach). 2
• Never perform endocervical curettage—this is absolutely contraindicated in pregnancy. 1, 2

Step 2: Determine if Invasive Cancer is Present

• If invasive cancer is suspected based on referral cytology, colposcopic appearance, or cervical biopsy results, diagnostic excision is acceptable. 2
• If no invasive cancer is suspected, defer all treatment until postpartum. 1, 2

Step 3: Postpartum Re-evaluation

• Re-evaluate with cytology and colposcopy no sooner than 6 weeks postpartum for pregnant women with HSIL in whom CIN 2-3 was not diagnosed during pregnancy. 2
• Definitive treatment can be performed postpartum using LEEP, cold-knife conization, cryotherapy, or laser ablation. 4, 3

Miscarriage Risk Data (When LEEP is Performed Outside Pregnancy)

While LEEP should not be performed during pregnancy, understanding the obstetric risks when performed before pregnancy is important:

• LEEP increases the risk of preterm delivery in subsequent pregnancies: Women with previous LEEP had 7.2% preterm deliveries compared to 4.6% in controls (OR 1.61,95% CI 1.47-1.75). 5
• Repeat LEEP carries nearly threefold risk for preterm delivery (OR 2.80,95% CI 2.28-3.44). 5
• The severity of CIN itself does not increase preterm delivery risk—the procedure itself is the risk factor. 5
• Time interval since LEEP was not associated with preterm delivery risk, meaning the risk persists regardless of how long ago the procedure was performed. 5

Common Pitfalls to Avoid

• Do not perform LEEP during pregnancy for CIN 2-3 management—the only indication is confirmed invasive cancer. 1, 2
• Do not defer colposcopy in pregnant women with HSIL—unlike ASC-US or LSIL where deferral is acceptable, HSIL carries high risk and requires evaluation. 2
• Do not use HPV testing for triage in HSIL—intermediate triage is inappropriate due to high disease risk. 4, 2
• Do not equate cytological HSIL with histological CIN 2-3—they are not interchangeable. 3
• Avoid repeat LEEP in women of reproductive age whenever possible due to the substantially increased preterm delivery risk. 5

Treatment After Pregnancy

• Both excisional (LEEP, cold-knife conization) and ablative methods (cryotherapy, laser) are acceptable with overall failure rates of 5-15% and no significant difference between modalities. 1, 3
• Excisional procedures are preferred as they allow pathologic assessment to rule out occult invasive cancer. 1, 3
• LEEP is faster, causes less intraoperative bleeding, and results in shorter hospital stay compared to cold-knife conization. 6