Intrauterine adhesions following an induced termination of pregnancy: a nationwide cohort study

OBJECTIVE Intrauterine adhesions (IUAs) are a problematic complication after termination of pregnancy, but their incidence is unknown. Our objective was to assess the incidence of IUAs following induced termination of pregnancy and the risk factors for IUAs. DESIGN Retrospective cohort study. SETTING A nationwide registry study. SAMPLE All women undergoing induced termination of pregnancy (n = 80 015) in Finland between 2000 and 2008. METHODS The data were retrieved from the Finnish Abortion Registry and the Hospital Discharge Registry. The diagnosis of IUAs or complications was based on the diagnostic codes (International Statistical Classification of Diseases and Related Health Problems 10th Revision, ICD-10) and operative codes according to the Nordic Medico-Statistical Committee (NOMESCO) Classification of Surgical Procedures (NCSP). IUAs were defined as ICD-10 code N85.6 or operative code LCG02. A subanalysis of IUA cases and five matched controls was performed. MAIN OUTCOME MEASURES The incidence of and risk factors for IUAs. RESULTS A total of 12 (1.5 per 10 000) IUA diagnoses were identified from 79 960 eligible induced terminations of pregnancy. The rate of IUAs was 1.5 and 2.0 cases per 10 000 terminations of pregnancy following medically and surgically induced termination of pregnancy, respectively (P = 0.19). In a subgroup analysis of IUA cases and five matched controls, surgical treatment of the remaining products of conception following termination of pregnancy significantly increased the risk of IUAs (odds ratio, OR 5.50; 95% confidence interval, 95% CI 1.46-20.79; P = 0.012). CONCLUSION IUAs that require further treatment are rare after an induced termination of pregnancy. Surgical evacuation following medical or surgical termination of pregnancy was a risk factor for the diagnosis of IUAs. These results suggest that trauma to a recently pregnant uterus is an important risk factor for IUAs. TWEETABLE ABSTRACT IUA is rare after induced termination of pregnancy (iTOP), but surgical evacuation is a risk factor for IUAs.