Strengths and limitations
A strength of our study is that, to the best of our knowledge, this is the first report to show the clinical characteristics of pain at the adenomyosis site during pregnancy. Another limitation is that we did not confirm the imaging findings that are linked to the manifestation of adenomyosis pain. However, as with degeneration in fibroids, diagnosis of adenomyosis pain during pregnancy seems sufficient to confirm the tenderness over the adenomyosis lesion with ultrasound after carefully excluding the possibility of intra-amniotic infection (IAI). Moreover, to elucidate the pathophysiology of pain at the adenomyosis site, pathological confirmation of the histological change in adenomyosis is warranted in future studies.