Clinical characteristics and outcomes of women with adenomyosis pain during pregnancy: a retrospective study

Objectives Adenomyosis is associated with unfavorable perinatal outcomes, and recent case reports show that some women with adenomyosis experience pain at the adenomyosis lesion during pregnancy and have detrimental perinatal outcomes. This study aimed to clarify the clinical characteristics of this pain and perinatal outcomes associated with this phenomenon.Methods This was a single-center retrospective analysis of pregnant women with adenomyosis. The incidence of pain onset at adenomyosis lesions, defined as persistent pain at the adenomyosis site with administration of analgesics for pain relief, and its association with perinatal outcomes were analyzed.Results Among 91 singleton pregnancies with adenomyosis, 12 pregnancies (13.2 %) presented with pain. One pregnancy resulted in second-trimester miscarriage, and 5 of the 11 pregnancies (45 %) developed preeclampsia, which resulted in preterm delivery, and 3 of the 12 pregnancies (25 %) achieved term delivery. The incidence of preeclampsia and preterm delivery was higher in those who experienced pain than in those without (45 % [5/11] vs. 15 % [11/74]; p<0.05, and 73 % [8/11] vs. 34 % [25/74]; p<0.05, respectively). Among women with pain, the maximum C-reactive protein level was significantly higher in women who developed preeclampsia than in those who did not (5.45 vs. 0.12 mg/dL, p<0.05).Conclusions Our study revealed that adenomyosis can cause pain in over one of eight pregnancies with adenomyosis, which may be associated with the increased incidence of preeclampsia resulting in preterm delivery. Women with pain, especially those with high C-reactive protein levels, may be at high risk for future development of preeclampsia and consequent preterm delivery.