We read with great interest the article titled “Congenital uterine anomalies and adverse pregnancy outcomes” by Meiling Hua et al (2011). However, the article contains a section that may not be correct regarding the incidence of preterm births <37 weeks by uterine anomalies, which requires the authors’ attention. And the article also has some confusing presentation in the “Materials and Methods,” “Results,” and “Comment” sections concerning the diagnosis of uterine anomalies.

First, focusing on the relationship between congenital uterine anomalies and adverse pregnancy outcomes in the figure by Hua et al, we think this is a very informative article. However, 25% for didelphys and 13% for septum may be typographical errors.

Secondly, we wonder how the authors diagnosed or detected congenital uterine anomalies. The authors stated that the morphology of the uterus was evaluated by “routine anatomic survey” in the “Materials and Methods” section, “anatomic survey” in the “Results” section, and “ultrasound diagnosis” in the “Comment” section.

The incidence of uterine anomalies has varied in previous reports. Simón et al reported that the incidence of uterine anomalies in the normal fertile population was 3.2%, 90% of which were septate uterus, and bicornuate and didelphys were 5% each. According to a report of Jurkovic et al, the incidence of uterine anomalies was 5.4%, confirmed by 3-dimensional ultrasound, in a population of outpatients at a gynecological ultrasound clinic. These varied data were likely caused by the characteristics of the population and the methods of examination employed. In this report by Hua et al, the prevalence of uterine anomalies was only 0.3% of their subjects. This discrepancy should be addressed. Saravelos and Cocksedge reviewed and concluded that 2-dimensional ultrasonography and/or hysterosalpingography should be used as the screening tool for detecting uterine anomalies, and that combined hysteroscopy and laparoscopy, sonohysterography, and 3-dimensional ultrasonography could be used for definitive diagnosis. The authors did not present how to examine the uterine anatomy precisely, which we believe requires clarification.