Activity of ankylosing spondylitis in women within one year after childbirth

Aim. To assess the dynamics of activity of ankylosing spondylitis (AS) during the year after childbirth, to identify predictors of high activity.

Materials and methods. 75 pregnant with confirmed AS (modified New York criteria, 1984) were included for prospective observation. Of these, 44 women were followed up for 1 year after delivery. The average age of the patients was 32.5±5.8 years, the duration of the disease was 149.0±96.3 months. Lactation was established in 40 women and the duration was 10 [4; 12] months.

Results. The BASDAI (Bath Ankylosing Spondylitis Disease Activity Index) at 1, 6 and 12 months after giving birth was 2.4 [1.4; 4.2], 2.6 [1.4; 4.4] and 2.7 [1.5; 4.1], respectively (p>0.05). ASDAS-CRP (Ankylosing Spondylitis Disease Activity Score – C-reactive protein) was 2.0 [1.2; 2.7], 1.9 [1.4; 2.5] and 1.7 [1.3; 2.3], respectively (p>0.05). There were no differences between the values of BASDAI, ASDAS-CRP between women with and without lactation. Predictors of high AS activity (BASDAI≥4) 1 month after delivery were: BASDAI≥4 in the 1st (odds ratio – OR 8.1; 95% confidence interval – CI 1,8–37,0) and 2nd trimesters of pregnancy (OR 5.1, 95% CI 1.2–20.6); NRS back pain >4 in the 2nd trimester (OR 4.3, 95% CI 1.1–17.2); cancellation of biological disease-modifying antirheumatic drugs therapy in the 1st trimester of pregnancy (OR 21.0, 95% CI 1.0–440.9). Predictors of high AS activity in 6 months after delivery were: BASDAI≥4 in the 1st (OR 6.5, 95% CI 1.5–28.7), in the 2nd (OR 6.7, 95% CI 1.6–27.8) and in the 3rd trimesters of pregnancy (OR 8.7, 95% CI 1.9–38.6); high activity in 1 month after delivery (OR 4.0, 95% CI 1.0–15.9).

Conclusion. AS activity remains stable for 1 year after delivery. High AS activity during pregnancy was a risk factor for high activity within 6 months after delivery.