Table 5.

Children of HLA-B27 positive mothers with AS are more likely to have axSpA than children of HLA-B27 positive fathers with AS

	Children with axSpA number (%)	Healthy children number (%)	Total
AS fathers (n=78)	15 (12.6%) (95% CI: 6.6% to 18.6%)	104 (87.4%)	119 (100%)
AS mothers (n=22)	12 (41.4%) (95% CI: 22.7% to 60.1%)	17 (58.6%)	29 (100%)
Total	27	121	148
p=0.00032

AS by modified New York criteria.

OR 4.89 with 95% CI 1.96 to 12.23.

Mean number of children for fathers: 119/78=1.53.

Mean number of children for mothers: 29/22=1.32.

Mean number of axSpA children.

For fathers: 15/78=0.19 (95% CI 0.10–0.27).

Mean number of axSpA children.

For mothers: 12/22=0.55 (95% CI 0.33 to 0.77).

AS, ankylosing spondylitis; axSpA, axial spondyloarthritis.