How adenomyosis changes throughout pregnancy: A retrospective cohort study

Objective To study how adenomyosis changes during pregnancy and to possibly correlate these changes to maternal and fetal outcomes. Methods Retrospective exploratory cohort study including 254 women with a pre-conceptional/first-trimester scan to document adenomyosis and known obstetric outcome. If visible, adenomyosis signs were documented in each trimester and postpartum. Mann-Whitney U tests or chi(2) tests were used for continuous and categorical variables, respectively. Results A globular uterus was reported in 79% (n = 52) of women with adenomyosis in the first trimester, in 38% (n = 20) and 2% (n = 1) of women in the second and third trimesters, respectively, and postpartum in 77% (n = 34) of women. Asymmetrical thickening (n = 20, 30%) and cysts (n = 15, 23%) were only visible in 1st trimester. Adenomyosis was associated with miscarriage (odds ratio [OR] 5.9, 95% confidence interval [CI] 2.4-14.9, P < 0.001) also in normal conception only (OR 5.1, 95% CI 1.8-14.2, P = 0.002) or adjusting for maternal age (adjusted OR 5.9, 95% CI 2.3-15.2, P < 0.001). Gestational age at delivery was lower in adenomyosis (P = 0.004); the cesarean section rate was higher than in controls (OR 2.5, 95% CI 1.3-4.8, P = 0.007) also adjusting for age (adjusted OR 2.07, 95% CI 1.06-4.08, P = 0.035). Conclusions Signs of adenomyosis were visible but progressively disappeared in pregnancy; adenomyosis was associated with an increased risk of early miscarriage. Prospective studies are needed to confirm our results.