Q&A: The Impact of AS on Pregnancy Outcomes

Outcomes of pregnancy are well studied in various rheumatic diseases, yet data is limited on these outcomes for women with ankylosing spondylitis (AS). It has remained unknown whether or not, more complications occur during pregnancy for this patient population compared with the general obstetric population.

Vikas Majithia, MD, MPH, division chief and program director of the fellowship program in the division of rheumatology at the University of Mississippi Medical Center, is the lead author of a new study¹ on AS outcomes in pregnancy, which he presented at the ACR/ARHP Annual Meeting 2018. Rheumatology Consultant caught up with Dr Majithia about his research. 

Rheumatology Consultant: How did your study come about? 

Vikas Majithia: We wanted to review this data because pregnancy outcomes have been well studied in a number of rheumatic disorders including rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). This raised our curiosity to see how AS impacts pregnancy.

AS belongs to a category of spondyloarthritides and are believed to be quite different from RA or SLE, and not have as much systemic inflammation. Also, previous small studies have yielded limited and conflicting information on pregnancy outcomes in patients with AS. The Nationwide Inpatient Sample (NIS) database lets us evaluate this kind of information with confidence as it has huge numbers, diverse geographic and ethnic populations, and is real-world data.

RHEUM CON: Why is there limited data in pregnancy outcomes for patients with AS? 

VM: Women tend to be less commonly affected by AS but are also frequently underdiagnosed. Overall, prevalence of AS is low, and it is difficult to find a big population of pregnant women with AS to provide a large enough sample size. 

RHEUM CON: In your study, results showed that the maternal AS population had no significant increase of inpatient mortality or fetal death. Were you surprised by these findings? 

VM: Somewhat, but not quite. As I pointed out earlier, due to low systemic inflammation, we hypothesized that these adverse complications will occur at a lower rate than other rheumatic conditions, but we certainly did not expect a really low rate of complications throughout. 

RHEUM CON: What is the key takeaway from the results of your study? Why is this important?  

VM: The takeaway is that women with AS had good maternal and fetal outcomes with no increase in common adverse complications. This is important because it provides reassuring information that pregnancy in these women may be safe, and appropriate counseling can be performed when this comes up at their visit with rheumatologists. It is also important, though, that appropriate antenatal/post-delivery monitoring be performed to ensure success.

RHEUM CON: What is the next step in your research?

VM: We want to work on getting it published soon. Also, we want to analyze additional years in NIS—2012 to 2016—to confirm these findings and also see if there any trends. The 2014 to 2016 data will include ICD-10 coded data and may provide additional insights. Also, we hope that this data stimulates large collaborative prospective cohort studies of pregnant women with AS, which can give the best long-term information on these very significant issues. 

For more on ankylosing spondylitis, visit the Resource Center.

Reference:

1. Majithia V, Kishore S. Pregnancy in women with ankylosing spondylitis is not associated with poor obstetric outcomes: analysis of Nationwide Inpatient Sample Database 2003-201 Paper presented at: 2018 ACR/ARHP Annual Meeting; October 19-24, 2018; Chicago IL. https://acrabstracts.org/abstract/pregnancy-in-women-with-ankylosing-spondylitis-is-not-associated-with-poor-obstetric-outcomes-analysis-of-nationwide-inpatient-sample-database-2003-2011/. Accessed October 19, 2018.