Adenomyosis and obstetric complications: A retrospective case-control study

Adenomyosis is a uterine pathology affecting an increasing number of women of childbearing age. Its diagnosis is based upon histology or imaging [ultrasound or magnetic resonance imaging (MRI)]. Several studies have investigated the impact of adenomyosis on obstetric complications, with its diagnosis based on clinical symptoms, ultrasound or composite criteria. The aim of this study was to identify potential obstetric complications related to adenomyosis in women with an MRI-confirmed diagnosis.

A single centre retrospective case-control study was undertaken in pregnant patients with an MRI-confirmed diagnosis of adenomyosis between January 2013 and December 2017 at the University Hospitals of Strasbourg. Controls were matched in a 4:1 ratio for age, parity and body mass index. Multivariate analysis was performed to identify obstetric complications.

In total, 291 women with an MRI-confirmed diagnosis of adenomyosis were identified during the study period. Of these, 89 patients achieved pregnancy after 24 weeks of gestation. The mean age of patients was 30.8 years. The adenomyosis group and the control group were comparable for matching criteria. Adenomyosis was found to be associated with increased risk of caesarean section [odds ratio (OR) 1.1, 95 % confidence interval (CI) 1.0-1.2; p = 0.03], intrauterine growth restriction (OR 1.3, 95 % CI 1.1-1.4; p < 0.001), postpartum haemorrhage (OR 1.2, 95 % CI 1.1- 1.4; p < 0.01), pre-eclampsia (OR 1.3, 95 % CI 1.0-1.6; p = 0.004) and previous spontaneous miscarriage (OR 2.09, 95 % CI 1.36-3.33; p < 0.001). Premature rupture of membranes, preterm delivery, severe intrauterine growth restriction and the risk of placenta praevia were not significantly higher in the adenomyosis group compared with the control group on multivariate analysis.

This study demonstrates increased risk of several obstetric complications (caesarean section, intrauterine growth restriction, postpartum haemorrhage, pre-eclampsia, history of spontaneous miscarriage) in women with adenomyosis. To the authors' knowledge, this is the first study to use MRI as the sole criterion for diagnosis. These results could be complemented by larger-scale prospective studies in order to manage these patients more effectively during pregnancy.