Impact of adenomyosis on perinatal outcomes: a large cohort study (JSOG database)

BACKGROUND: A previous study investigated the effect of adenomyosis on perinatal outcomes. Some studies have reported varying effect of adenomyosis on pregnancy outcomes in some patients and dependence on the degree and subtype of uterine lesions. To elucidate the impact of adenomyosis on perinatal outcomes. METHODS: This large-scale cohort study used the perinatal registry database of the Japan Society of Obstetrics and Gynecology. A dataset of 203,745 mothers who gave birth between January 2020 and December 2020 in Japan was included in the study. The participants were divided into two groups based on the presence or absence of adenomyosis. Information regarding the use of fertility treatment, delivery, obstetric complications, maternal treatments, infant, fetal appendages, obstetric history, underlying diseases, infectious diseases, use of drugs, and maternal and infant death were compared between the groups. RESULTS: In total, 1,204 participants had a history of adenomyosis and 151,105 did not. The adenomyosis group had higher rates of uterine rupture (0.2% vs. 0.01%, P = 0.02) and placenta accreta (2.0% vs. 0.5%, P < 0.001) than the non-adenomyosis group. A history of adenomyosis (odds ratio: 2.26; 95% confidence interval: 1.43–3.27; P < 0.001), uterine rupture (odds ratio: 3.45; 95% confidence interval: 0.89–19.65; P = 0.02), placental abruption (odds ratio: 2.11; 95% confidence interval: 1.27–3.31; P < 0.01), and fetal growth restriction (odds ratio: 2.66; 95% confidence interval: 2.00–3.48; P < 0.01) were independent risk factors for placenta accreta. CONCLUSION: Adenomyosis in pregnancies is associated with an increased risk of placenta accreta, uterine rupture, placental abruption, and fetal growth restriction. TRIAL REGISTRATION: Institutional Review Board of Tottori University Hospital (IRB no. 21A244).