Introduction
Uterine adenomyosis is a benign disorder in which endometrial tissues are present within the myometrium, and it is associated with abnormal uterine bleeding, dysmenorrhea, pelvic pain, and infertility.(1) (2) Moreover, adenomyosis is also known to be associated with unfavorable perinatal outcomes, with increased incidence of preterm delivery, preeclampsia (PE), cesarean delivery, postpartum hemorrhage (PPH), and small for gestational age infants. (3-8) However, the pathophysiology underlying this etiology remains to be elucidated, along with the clinical factors associated with adenomyosis that are responsible for these outcomes.
Several cases of adenomyosis accompanied by severe pain and enhanced inflammatory response during pregnancy that showed degenerative changes, which were confirmed with magnetic resonance imaging, have been reported since 2006, including one from our institution.(9) (10) (11) Intriguingly, all of the cases developed either preterm delivery, miscarriage, preeclampsia, or non-reassuring fetal status. Although fibroids are reported to degenerate during pregnancy and cause pain and enhanced inflammation in 12.6-28.0% of these women,(12),(13) the incidence of pain and enhanced inflammation during pregnancy among women with adenomyosis has not been reported, nor has its degeneration during pregnancy and its impact on perinatal outcomes.
Our main objective was to evaluate the clinical characteristics of pain at the adenomyosis site during pregnancy. We also compared perinatal outcomes between those who experienced pain and those who did not among pregnant women with adenomyosis to investigate whether this pain, suggesting degeneration during pregnancy, affects perinatal outcomes.