Many persist, but a five-year follow-up tells the true story.
Mothers are no more likely to develop structural MRI lesions during the five years after delivery, in a “stark contrast to the natural evolution of inflammatory lesions in axSpA”, according to new Belgian research.
The study of 19 women, all of whom had an uncomplicated vaginal delivery, also showed that bone marrow oedema was prevalent with higher Spondyloarthritis Research Consortium of Canada (SPARCC) scores in blue collar workers who performed physical labour.
“Even in these postpartum women subjected to more mechanical stress, no substantial evolution in structural lesions was seen in our cohort, even though blue-collar labour has been associated with more pronounced structural progression in axSpA,” the authors wrote in RMD Open.
“Yet, a new delivery during follow-up was linked to the total number of structural lesions at year five, whereas mean weight gain across all pregnancies correlated with sclerosis.”
The healthy subjects, who did not have spondyloarthritis and who were 35 years old on average, were given an MRI following their delivery and again five years later.
At baseline, the researchers found that six of the participants reported back pain and one reported inflammatory back pain.
They found no link between inflammatory back pain and SPARCC scores or a positive MRI as defined by the Assessment of SpondyloArthritis international Society (ASAS) definition.
At the five-year follow-up, they found that one in three participants presented with bone marrow oedema, and three of these participants met the ASAS definition of a positive MRI for sacroiliac joints. This was regardless of any additional pregnancies in the interim.
Participants who performed physical labour had a median SPARCC score of 5.5 out of 72 compared to 0 in the group who didn’t perform physical labour.
Patients with bone marrow oedema lesions at follow-up did not report back pain symptoms. And the presence of these lesions wasn’t associated with subsequent delivery.
Nevertheless, a delivery in the follow-up period was linked to the overall number of structural lesions at follow-up and the woman who gave birth to four children had the highest sclerosis score, at 10 out of 48. Weight gain was also correlated with sclerosis.
“In postpartum women, no significant development of structural MRI lesions was observed five years after a single delivery, despite the presence of bone marrow oedema in a significant number of individuals postpartum and at follow-up,” the authors wrote.
“These results support the hypothesis that, unlike bone marrow oedema in SpA, childbirth-related mechanical stress-induced bone marrow oedema does not lead to structural lesions. However, subsequent pregnancies may contribute to their development.”
