Estimated prevalence of müllerian anomalies.

Among 167 women who underwent laparoscopic sterilization in the course of one year, 1.2% were found to have a bicornuate uterus. Of them, 111 were offered follow-up by hysterosalpingography (HSG), and the history of their menstrual pattern as well as reproductive potential was recorded. Evaluation of the HSG exposures revealed 3.6% moderately to severely septate uteri (H/L greater than 0.20), and a total of 15.3% had fundal anomalies (H/L greater than 0.10). In women who had always had normal fertility and menstrual cycles of less than 35 days, the corresponding frequencies of septate uterus were 1.2% and 11.8% respectively. Among women who had had oligomenorrheic periods exceeding one year in duration, the frequency of müllerian anomalies was significantly higher (21.1% at H/L greater than 0.20 and 36.8% at H/L greater than 0.10) than in the above-mentioned groups. A control group of infertile oligomenorrheic women revealed that the material was comparable with previously published populations as regard the occurrence of minor müllerian anomalies. It is concluded that the HSG-diagnosed prevalence of developmental uterine anomalies is in general somewhat higher than usually assumed.