Does pregnancy increase curve progression in women with scoliosis treated without surgery?

Study design: Systematic review. Study rationale: It is commonly believed that scoliosis treated nonoperatively does not worsen in pregnancy; however, at times patients with scoliosis progress rapidly during these months. Objective or clinical question: What is the level of evidence to support or deny the claim that scoliosis treated nonoperatively does not worsen in pregnancy? Methods: A systematic review of the literature was undertaken for articles published through March 2011. PubMed, Cochrane, National Guideline Clearinghouse Databases as well as bibliographies of key articles were searched. Two independent authors reviewed articles. Inclusion and exclusion criteria were set and each article was subject to a predefined quality-rating scheme. Results: We identified two articles meeting our inclusion criteria. There was no difference in risk of curve progression > 5° or > 10° between women who had one or more pregnancies compared with those who had never been pregnant. However, among women who had been treated with an orthosis, those with one or more pregnancies had a higher risk of curve progression > 5° compared with never-pregnant women: relative risk = 8.1 (95% confidence interval: 1.8–35.8) in one study and 1.9 (95% confidence interval: 0.8–4.3) in the other. While women with more severe curves had a higher risk of curve progression, having one or more pregnancies did not appear to modify the effect of curve severity. Conclusions: Having one or more pregnancies does not appear to affect curve progression in scoliosis. However, among patients who had prior orthotic treatment, there is some evidence to suggest that women experiencing one or more pregnancies had a higher risk of curve progression compared with never-pregnant women. The overall strength of evidence for this conclusion is low.