Perinatal Patterns of Medication Use in Women with Rheumatoid
Arthritis: A Population-based Study

Background/Purpose: Although the incidence of RA peaks during the 4^th and 5^th
decades of life, a substantial proportion of women are also affected during the
more common childbearing years. Given the limited
data on perinatal medication use, including traditional and biologic DMARDs as
well as other medications, our objective was to characterize real-world therapy
patterns among women with RA before, during, and after pregnancy.

Methods: We linked population-based health data on all
visits to health professionals and hospital admissions (01/01/1992 –
12/31/2012) and all dispensed medications, regardless of payer (01/01/1996
– 12/31/2012) with a perinatal registry capturing information on >99%
of births in hospitals and homes in the province of British Columbia, Canada (01/01/2002
– 12/31/2012). Unique to this pregnancy cohort is valid,
clinically-derived information on date of conception according to gestational
age or date of last menstrual period as confirmed by ultrasound. The case
definition for RA was 2 outpatient ICD9 codes for RA ³2 months apart and we
excluded individuals with a non-RA coded subsequent visit to a rheumatologist
or no subsequent RA-coded visits during the last 5 years of follow-up. Using
information on prescription date and days supply, we determined the use of traditional
and biologic DMARDs, glucocorticosteroids, and NSAIDs for the following
periods: 1) pre-conception 1 (366-730
days before conception); 2) pre-conception
2 (1-365 days before conception); 3)
1^st trimester; 4) 2^nd
trimester; 5) 3^rd trimester; and
6) post-delivery (1-365 days after
delivery).

Results: We identified 513 pregnancies in 414 women with
RA; 80% of women were primipara and 20% multipara.  At delivery, mean age was 31.3 ±
5.4 years. We tabulated the proportion of exposed pregnancies according to each
period and medication class (Table).
The majority of traditional DMARD pregnancy exposures were to
hydroxychloroquine and/or chloroquine (proportion of pregnancies exposed during
the 1^st, 2^nd, and 3^rd trimester were 17.0,
10.7 and 9.2%, respectively) and the majority of biologic pregnancy exposures
were to anti-TNFs (4.7, 2.1 and 2.1%). 
For all medications, we observed a decline in use during pregnancy
followed by increased use in the year following delivery.

Conclusion: This population-based study provides
data on real-world patterns of perinatal medication use among women with RA.
Findings emphasize the importance of counseling women regarding childbearing
decisions as well as the need for evaluation of the risk-benefit profiles of
medications in pregnancy.