Adenomyosis and adverse perinatal outcomes: increased risk of second trimester miscarriage, preeclampsia, and placental malposition

<p><b>Objective:</b> To evaluate the potential impact of adenomyosis on the pregnancy outcomes by retrospectively investigating adenomyosis-complicated pregnancy cases.</p> <p><b>Methods:</b> We performed a retrospective case–control study. Forty-nine singleton pregnancy cases complicated with adenomyosis were included in this study. The controls (<i>n</i> = 245) were singleton pregnant women without adenomyosis and were frequency matched to adenomyosis cases by age, parity, and the need for assisted reproductive technology for this conception. The incidence of obstetrical complications and delivery and neonatal outcomes were examined.</p> <p><b>Results:</b> Patients in the adenomyosis group were significantly more likely to have a second trimester miscarriage (12.2% versus 1.2%, odds ratio (OR): 11.2, 95% confidence interval (95% CI): 2.2–71.2), preeclampsia (18.3% versus 1.2%, OR: 21.0, 95% CI: 4.8–124.5), placental malposition (14.2% versus 3.2%, OR: 4.9, 95% CI: 1.4–16.3), and preterm delivery (24.4% versus 9.3%, OR: 3.1, 95% CI: 1.2–7.2), compared with the control group.</p> <p><b>Conclusion:</b> Adenomyosis was associated not only with an increased incidence of preterm delivery, as previously reported, but also with an increased risk of second trimester miscarriage, preeclampsia, and placental malposition, which could lead to poor perinatal outcomes.</p>