Risk of preterm birth after treatment for cervical intraepithelial neoplasia among women having Large Loop Excision of the Transformation Zone (LLETZ): a retrospective analysis.

Keywords: Key words: Large loop excision of the transformation zone (LLETZ); Preterm delivery.


Objective: To assess the risk of: severe preterm (< 34 weeks) delivery, extreme preterm (< 28 weeks delivery, perinatal mortality, and low birth weight associated with previous LLETZ to cervix.

Design: Retrospective data collected from Euroking, ‘joe’ and e-searcher systems of 407 cases. Cases analyzed to identify singleton live births between 20-43 gestational weeks before or after cervical histology. 

 Setting: East Sussex Healthcare Trust

Population: Women who had LLETZ treatment for cervical intraepithelial neoplasia (CIN) in the colposcopy service, and who subsequently had a pregnancy at the East Sussex hospital. Case records and histology reports for women were studied. Exclusion criteria were age >42 years, previous premature labour or twin pregnancies.

Main outcome measures Proportion of preterm births (<37 weeks); the relative risk for the strength of association between preterm births and treatment for cervical intraepithelial neoplasia.

Result: Total number of deliveries in East Sussex hospital in a year were 4349 and the deliveries at term gestation (37 +) were 4057. Total number of all preterm deliveries were 268 (6.16 %), 34 to 36+6 weeks were 198 (4.55 %) and less than 34 weeks were 70 (1.6 %). In 24 cases gestation was unknown.

Total number of data was collected of 407 LLETZ treatment cases. Total number of preterm deliveries less than 37 weeks was 45 (11 %) as against background risk of 6.16%.  Fifteen of these 45 women had term pregnancies prior to LLETZ whereas others were pregnant for the first time beyond 16 weeks after having LLETZ.

Conclusion: LLETZ increases the risk of preterm delivery.

Key words: Large loop excision of the transformation zone (LLETZ); Preterm delivery.

Original Articles