We thank Drs Matsushita, Ogawa, and Matsuda for their interest in our article. In their letter to the editor, they requested clarification regarding the diagnosis of uterine anomalies. The anomalies were diagnosed during the routine anatomy ultrasound, which is a 2-dimensional ultrasound that occurs typically in the second trimester. The words “routine anatomic survey” and “anatomy ultrasound” are used interchangeably throughout the manuscript.

Dr Matsushita et al also note that the incidence of uterine anomalies was lower in our cohort compared to other published studies. We agree with Dr Matsushita et al that the method of diagnosis likely contributes to the discrepancy. We acknowledge that ultrasound is not the most sensitive method to diagnose uterine anomalies. However, we believe that the consequence of this is that uterine anomalies are underdiagnosed in our control population, thus biasing our results toward the null.

Dr Matsushita et al are correct that there is a typo in the “Results” section and we appreciate the opportunity to clarify it. The statement should read: “while uterine didelphys accounts for only 25% of the uterine anomalies, they had a higher proportion of preterm birth <34 weeks and <37 weeks than any other subgroup.”

Lastly, Dr Matsushita et al request that we recommend an ideal method of diagnosing a uterine anomaly. Methods cited in the letter to the editors include hysterosalpingogram, sonohysterography, laparoscopy, and magnetic resonance imaging; however, these studies are not routinely performed on pregnant women. We regret that our study does not further clarify methods of diagnosing uterine anomalies. Our study’s aim was not to investigate imaging modality but rather to provide data regarding pregnancy outcomes for fertile women in whom uterine anomalies are diagnosed during the second trimester of pregnancy.