Are all Inflammatory Arthritides Created Equal in Pregnancy?

As a full disclosure, one of the abstracts I will refer to (#992) is my own – and yet it fits well with my Rheum Reporter assignment to cover pregnancy and rheumatic diseases. More importantly, I think it provides Canadian context to the impact of rheumatic diseases on pregnancy.

My colleagues at the Canadian Vigour Centre (Kaul and Savu) assembled a pregnancy cohort of all female Albertans from January 1, 2005 to December 31, 2014 with all inpatient and outpatient visits, to evaluate the hypothesis that women with inflammatory arthritis (IA) (rheumatoid arthritis [RA] or spondyloarthritis [SpA], AS, or psoriatic arthritis/psoriasis) have worse obstetrical and neonatal outcomes compared to those without these diagnoses.

We found that among females, women with either RA (n=631) or SpA (n=2461) were a little bit older (~30.4 years vs 29.3 years), with slightly higher numbers in both groups of IA coming from rural residences compared to females without IA females (n=308,989). There were more women with RA with aboriginal status compared to the other groups. We found more hypertension, diabetes and thyroid disease in the women with either RA or SpA. Women with RA were more likely than either "No IA" or "SpA" to have preterm delivery (13.5% vs 7%), C-sections (33.9% vs ~ 28%) and hypertensive syndromes such as preclampsia (10.5% vs 6-7%). Neonatal outcomes were also worse for RA females compared to either "No IA" or "SpA" with small for gestational age babies and more days spent in NICU for the RA group. The odds of a small for gestational age baby was 1.51 (95% CI 1.21-1.87) compared to SpA 0.97 (95% CI 0.85-1.10) when adjusting for factors such as age, comorbidities, and income.

So what does this mean? Well, RA appears to confer different effects than SpA on pregnancy-related outcomes. When we just compared RA to psoriasis and psoriatic arthritis, the results stayed the same. This is in contrast to Dr. Amiri's work (Abstract #2443) that evaluated 180 women with psoriasis/psoriatic arthritis (PsO/PsA) from the OTIS registry (Organization of Teratology Information Specialists) Autoimmune Diseases in Pregnancy project, and compared these to 379 non-diseased women. In addition to higher pre-pregnancy obesity, smoking and illicit drug use in the PsO/PsA groups, the PsO/PsA women had more depression and like our work, more hypertension. Moreover, the pregnant PsO/PsA females were at increased risk of C-section (RR 1.42 (95% CI 1.10-1.83), and preterm birth (RR 1.81 (95% CI 1.02-3.23) compared to unexposed females, which is different from our work. She also found no increased risk of pre-eclampsia or small for gestational age, consistent with our findings.

More work is needed to clarify important factors that were not addressed in either study: the impact of disease activity and severity as well as medications on these outcomes. For RA patients, the impact of seropositivity may also be important.

More reports from ACR 2016