title: Loop electrosurgical excision of the cervix and risk for spontaneous preterm delivery in twin pregnancies.
abstract: OBJECTIVE
  To investigate the association between three cervical procedures (biopsy with no treatment, ablation, and loop electrosurgical excision procedure [LEEP]) and subsequent spontaneous preterm delivery in twin pregnancies using population-based data from various nationwide registries.
  
  
  METHODS
  : The study population consisted of all twin deliveries in Denmark during a 9-year period, 1997-2005. Information on the deliveries, including cervical procedures, was obtained from various national registries. In all, 9,868 deliveries were eligible for analyses, of which 3,228 were delivered spontaneously preterm (32.7%). Preterm delivery was defined as gestational age between 21 weeks and 37 weeks. Logistic regression analyses were used to evaluate the association between cervical procedures and preterm delivery.
  
  
  RESULTS
  Twin pregnancies subsequent to LEEP had a significantly increased risk of overall subsequent spontaneous preterm delivery (43.4%) with an adjusted odds ratio of 1.58 (95% confidence interval 1.16-2.14) compared with pregnancies with no prior LEEP (32.5%). The association was consistent in various secondary analyses and especially strong for the very preterm and extremely preterm groups. We found no increase in risk of preterm delivery subsequent to biopsy without treatment or ablation.
  
  
  CONCLUSIONS
  Our study showed an overall significant increase in risk of preterm delivery in twin pregnancies subsequent to LEEP treatment, even after adjustment for several potential risk factors.
  
  
  METHODS
  II.
authors.affiliation: From the Institute of Cancer Epidemiology, Danish Cancer Society; Department of Foetal Medicine and Ultrasound, Juliane Marie Centre, Rigshospitalet; and Department of Gynaecology and Obstetrics, Juliane Marie Centre, Rigshospitalet, Copenhagen, Denmark.
authors.forename: Bugge
authors.initials: B
authors.lastname: Noehr
authors.forename: Allan
authors.initials: A
authors.lastname: Jensen
authors.forename: Kirsten
authors.initials: K
authors.lastname: Frederiksen
authors.forename: Ann
authors.initials: A
authors.lastname: Tabor
authors.forename: Susanne K
authors.initials: SK
authors.lastname: Kjaer
mesh_terms: D055011:Ablation Techniques; D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D019092:Conization; D004598:Electrosurgery; D005260:Female; D006801:Humans; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000473:pathology* / Q000601:surgery; D011272:Pregnancy, Multiple; D047928:Premature Birth / Q000453:epidemiology* / Q000473:pathology; D012189:Retrospective Studies; D012307:Risk Factors; D014427:Twins; D002583:Uterine Cervical Neoplasms / Q000150:complications / Q000473:pathology / Q000601:surgery*; D055815:Young Adult; D002578:Uterine Cervical Dysplasia / Q000150:complications / Q000473:pathology / Q000601:surgery*
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