Background/Purpose:   While it has long been reported that rheumatoid arthritis (RA) improves with pregnancy, there is very limited information about ankylosing spondylitis (AS) or psoriatic arthritis (PsA).  We sought to explore similarities and differences between disease activity and treatment in pregnancy, delivery, and the postpartum experience for women with RA, AS, and PsA. 

Methods:   The pregnancies in women with RA, juvenile inflammatory arthritis (JIA), AS, other spondyloarthropathies (Spondy), and PsA were collected through a prospective pregnancy registry collected at a single center.  For analysis, pregnancies were divided into 3 groups by diagnosis: RA & JIA, AS & Spondy, and PsA.   Medications, disease activity, and pregnancy complications were collected throughout pregnancy to a post-partum visit.  The physician’s global assessment (PGA) was used to compare disease activity between the diseases.    Non-parametric statistical testing was used due to small sample sizes.  A generalized estimating equation controlled for multiple pregnancies in some women. 

Results:   62 pregnancies in 50 women were completed between January 2008 and May 2014.  Of these, 37 were in women with RA (including 10 with JIA), 17 with AS/Spondy (including 11 with AS and 6 with other forms), and 8 with PsA (see table).    Disease Activity:  While the large majority of women with RA (96.5%) or AS/Spondy (80%) had either improved or stable disease activity over the course of pregnancy, 40% of women with PsA had increasing disease activity (p=0.02).  Medications:   Overall, 32.2% took no medications for arthritis in pregnancy, 8% took only prednisone, 21% took SSZ, HCQ, and/or a TNF inhibitor and prednisone, and 38.7% took SSZ, HCQ, and/or a TNF inhibitor without prednisone.  About a third (35.5%) of all pregnancies received TNF-inhibitors.  Medication use was similar across the diagnoses (see table)

Pregnancy Outcomes: Half of the pregnancies in women with PsA were complicated by preeclampsia and/or preterm birth, compared to 18.9% with RA and 5.9% with AS (p=0.046).   Overall, prednisone exposure was associated with preterm birth and/or preeclampsia (38.9%) compared to those without prednisone exposure (11.4%, p=0.029).

Postpartum:  Women with PsA continued to have more active disease than other women; AS/spondy patients improved following delivery.  Breastfeeding:  Far fewer women with PsA (14.3%) were breastfeeding at follow-up, compared to women with RA (76.9%) or AS/Spondy (80%, p=0.006). 

Conclusion:   It appears that the experience in pregnancy may be different for women with PsA compared to women with RA or AS/Spondy, with higher levels of disease activity as pregnancy progresses and following delivery, a higher rate of preterm birth and preeclampsia, and greater difficulties with breastfeeding.  This small cohort demonstrates an urgency to study PsA in pregnancy.