The ADENO study: ADenomyosis and its Effect on Neonatal and Obstetric outcomes: a retrospective population-based study.

BACKGROUND:Adenomyosis is a benign gynecologic condition arising from the uterine junctional zone. Recent studies suggest a relationship between adenomyosis and adverse obstetrical outcomes, but evidence remains conflicting. There is no large-scale study investigating obstetrical outcomes in women with adenomyosis using the gold standard of histopathologic diagnosis. OBJECTIVE:This study aimed to investigate the prevalence of adverse obstetrical and neonatal outcomes in women with histopathologic adenomyosis and that of the general (Dutch) population. STUDY DESIGN:This retrospective population-based study used 2 Dutch national databases (Perined, the perinatal registry, and the nationwide pathology databank [Pathologisch Anatomisch Landelijk Geautomiseerd Archief], from 1995 to 2018) to compare obstetrical outcomes in women before histopathologic adenomyosis diagnosis to the general Dutch population without registered histopathologic adenomyosis. The adjusted odds ratios (95% confidence interval) were calculated for adverse obstetrical outcomes. The outcomes were adjusted for maternal age, parity, ethnicity, year of registered birth, induction of labor, hypertensive disorders in previous pregnancies, multiple gestation, and low socioeconomic status. RESULTS:The pregnancy outcomes of 7925 women with histopathologic adenomyosis were compared with that of 4,615,803 women without registered adenomyosis. When adjusted for confounders, women with adenomyosis had adjusted odds ratios of 1.37 (95% confidence interval, 1.25-1.50) for hypertensive disorders, 1.37 (95% confidence interval, 1.25-1.51) for preeclampsia, 1.15 (95% confidence interval, 1.07-1.25) for small-for-gestational-age infants, 1.54 (95% confidence interval, 1.41-1.68) for emergency cesarean delivery, 1.24 (95% confidence interval, 1.12-1.37) for failure to progress, 1.29 (95% confidence interval, 1.10-1.48) for placental retention, and 1.23 (95% confidence interval, 1.10-1.38) for postpartum hemorrhage. No increased risk of HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome, placental abruption, or operative vaginal delivery or need for oxytocin stimulation was found. CONCLUSION:Women with a histopathologic diagnosis of adenomyosis showed an increased prevalence of hypertensive disorders of pregnancy and small-for-gestational-age infants, failure to progress in labor, and placental retention compared with the general population in previous pregnancies. This suggests that uterine (contractile) function in labor and during pregnancy is impaired in women with adenomyosis.