High prevalence of spondyloarthritis-like MRI lesions in postpartum women: a prospective analysis in relation to maternal, child and birth characteristics

Abstract

ObjectivesBone marrow oedema (BMO) on MRI of sacroiliac joints (SIJs) represents a hallmark of axial spondyloarthritis (SpA), yet such lesions may also occur under augmented mechanical stress in healthy subjects. We therefore sought to delineate the relationship between pregnancy/delivery and pelvic stress through a prospective study with repeated MRI. Results were matched with maternal, child and birth characteristics.MethodsThirty-five women underwent a baseline MRI-SIJ within the first 10 days after giving birth. MRI was repeated after 6 months and, if positive for sacroiliitis according to the Assessment of SpondyloArthritis International Society (ASAS) definition, after 12 months. BMO and structural lesions were scored by three trained readers using the Spondyloarthritis Research Consortium of Canada (SPARCC) method.ResultsSeventy-seven per cent of the subjects (27/35) displayed sacroiliac BMO immediately postpartum, 60% fulfilled the ASAS definition of a positive MRI. After 6 months, 46% of the subjects (15/33) still showed BMO, representing 15% (5/33) with a positive MRI. After 12 months, MRI was still positive in 12% of the subjects (4/33). Few structural lesions were detected. Intriguingly, in this study, the presence of BMO was related to a shorter duration of labour and lack of epidural anaesthesia.ConclusionA surprisingly high prevalence of sacroiliac BMO occurs in women immediately postpartum. Our data reveal a need for a waiting period of at least 6 months to perform an MRI-SIJ in postpartum women with back pain. This study also underscores the importance of interpreting MRI-SIJ findings in the appropriate clinical context.

Ultrasound-guided epidural block in axial spondyloarthritis patients with limited spine mobility: a randomized controlled trial

“…They pointed out that epidural anesthesia has a significant effect on reduction of this bone marrow edema. This finding strongly supports our results and signifies the role of epidural anesthesia in controlling sacroiliac joint inflammation [45].…”

“…In a recent study by Renson and his colleagues [45], 77% of female patients had sacroiliac bone marrow edema 10 days after labor and 46% of them still had bone marrow edema after 6 months. This percentage went down to 12% after 12 months.…”

Which factors are associated with bone marrow oedema suspicious of axial spondyloarthritis as detected by MRI in the sacroiliac joints and the spine in the general population?

“…However, the result is clinically plausible, looking at the reported prevalence of MRI 29 and CT 30 findings of osteitis condensans ilii (OCI) in young patients with symptoms of low back pain. In a recent Belgian study, 10 27 (77%) out of 35 women developed sacroiliac BME immediately postpartum, with 60% fulfilling the ASAS definition of a positive MRI in axSpA. Importantly, after 6 months, BME was still present in 46% of the participants.…”

“…7 8 Furthermore, these changes may also occur in situations with physical demanding activities 9 or after pregnancy. 10 The pathogenesis of axSpA is not fully understood to date but it seems to be largely genetically determined. 11 HLA-B27 is itself responsible for about 20% of the total genetic risk 11 and HLA-B27+ individuals carry a 10-20-fold increased risk of developing SpA.…”

Edema-like marrow signal intensity: a narrative review with a pictorial essay

“…For this reason, when an axial spondyloarthropathy is suspected, it is reasonable to wait at least 6 months to perform an MRI in postpartum women, and, if positive, repeat the exam after 12 months. The evolution of this physiological condition towards a true spondyloarthropathy seems coincidental, since the prevalence of peripartum women with ELMSI of the sacroiliac joints is not far greater than would be expected in a young patient population (< 4%) [35,36].…”