Table 2

MRI findings at the sacroiliac joints

Nulliparous (NP)Early post partum (EPP)Late post partum (LPP)P value
n=219n=60n=144NP versus EPPNP versus LPPEPP versus LPP
n (%)n (%)n (%)
BME*31 (14)20 (33)30 (21) 0.001 0.1140.074
 Unilateral23 (11)8 (13)18 (13)
 Bilateral8 (4)12 (20)12 (8)
Positive ASAS MRI criteria for sacroilitis22 (10)15 (25)24 (17)1.0000.5540.736
Erosions*10 (5)4 (7)9 (6)0.5100.4801.000
Condensation40 (18)23 (38)41 (29) 0.001 0.029 0.135
Ankylosis0 (0)0 (0)0 (0)
Osteophytes*60 (27)17 (28)60 (42)0.869 0.006 0.109
  • NP, had never given birth.

  • EPP, had given birth within the 12 months preceding MRI acquisition.

  • LPP, had given birth more than 24 months prior to MRI acquisition.

  • Underlined p-values are statistically significant.

  • *At least one observation.

  • ASAS, Assessment of SpondyloArthritis international Society; BME, bone marrow oedema.