Müllerian duct anomalies diagnosed by saline contrast sonohysterography: prevalence in a general population.

OBJECTIVE To estimate the prevalence of uterine müllerian duct anomalies in a general population. DESIGN Cross-sectional study. SETTING University hospital in collaboration with the Danish Civil Registry. PATIENT(S) A total of 1,654 women randomly recruited from a general population; 686 women were eligible and accepted inclusion (429 pre- and 257 postmenopausal). Saline contrast sonohysterography (SCSH) was finally performed in 622 women (aged 20-74 years) (the procedure was impossible owing to cervical stenosis in 58, contraindicated in 2, other patient-related factors in 4). INTERVENTION(S) The shape of the uterus was dynamically evaluated in the transversal and longitudinal planes during SCSH and classified in accordance with American Fertility Society as normal, arcuate, septate (partial, complete), bicorn (partial, complete), or unicorn. History of previous miscarriage and menstrual cycle was obtained by a questionnaire. MAIN OUTCOME MEASURE(S) Prevalence of müllerian anomalies, miscarriage, and oligomenorrhea. RESULT(S) The overall prevalence of müllerian anomalies was 9.8% (61 of 622) (95% confidence interval [CI] 7.5-12.1). The majority had arcuate uteri (n=42, 6.8%), 17 partial septate (2.7%), 1 complete septate (1.6%), and 1 unicorn uterus (1.6%). Müllerian anomalies were significantly more frequently diagnosed in nulliparous (20% [26 of 128]) compared with parous women (7% [35 of 494]). Müllerian anomalies were more frequent in women with oligomenorrhea compared with women with normal menstrual periods (19% [15 of 79] vs. 10% [34 of 339]). One first-trimester miscarriage or multiple miscarriages (more than one) were not significantly more frequent in premenopausal women with müllerian anomalies compared with women with normal-shaped uteri (24% [6 of 25] vs. 22% [57 of 265]). CONCLUSION(S) In a general population examined by SCSH the prevalence of Müllerian anomalies is estimated at 9.8%. Müllerian anomalies were more frequent in nulliparous women. Both impaired fertility and a pregnancy-associated modulation of the uterine corpus are among explanations. Müllerian anomalies were associated with oligomenorrhea in premenopausal women. In this general population there was no association between miscarriage and müllerian anomalies; however, the number of cases was limited.