The Danish National Research Foundation established the Danish Epidemiology Science Centre, which created the Danish National Birth Cohort.
Time to pregnancy among women with rheumatoid arthritis†
Article first published online: 31 MAY 2011
Copyright © 2011 by the American College of Rheumatology
Arthritis & Rheumatism
Volume 63, Issue 6, pages 1517–1521, June 2011
How to Cite
Jawaheer, D., Zhu, J. L., Nohr, E. A. and Olsen, J. (2011), Time to pregnancy among women with rheumatoid arthritis. Arthritis & Rheumatism, 63: 1517–1521. doi: 10.1002/art.30327
- Issue published online: 31 MAY 2011
- Article first published online: 31 MAY 2011
- Accepted manuscript online: 4 MAR 2011 01:30PM EST
- Manuscript Accepted: 24 FEB 2011
- Manuscript Received: 23 SEP 2010
- NIH (National Institute of Arthritis and Musculoskeletal and Skin Diseases Career Development award). Grant Number: K01-AR-053496
- The Danish National Birth Cohort is supported by a major grant from the Danish National Research Foundation
- Pharmacy Foundation
- Egmont Foundation
- March of Dimes Birth Defects Foundation
- Augustinus Foundation
- Health Foundation
To assess whether onset of rheumatoid arthritis (RA) prior to conception is associated with a delayed time to pregnancy (TTP).
The study included pregnant women from across Denmark who enrolled in the Danish National Birth Cohort between 1996 and 2002 and had planned or partly planned the cohort pregnancy. RA diagnosis was identified using the Danish National Hospital Discharge Registry. Self-reported data, including TTP, maternal age, parity, prepregnancy height and weight, maternal occupational status, smoking, and alcohol consumption, were collected using a detailed computer-assisted telephone interview at ∼16 weeks of gestation. We used logistic regression analyses as well as a complementary log regression model to examine whether TTP was influenced by RA, adjusting for the abovementioned variables.
Overall, compared with women with no recorded RA (n = 74,255), women with prevalent RA (onset prior to conception) (n = 112) were slightly older (mean ± SD age 30.8 ± 4.3 years versus 29.7 ± 4.1 years), were more likely to have been treated for infertility (9.8% versus 7.6%), and were more likely to have taken >12 months to conceive (25.0% versus 15.6%). The association between RA and TTP was borderline significant after adjusting for covariates in the regression analyses (odds ratio 1.6 [95% confidence interval 1.0–2.4]). Similar results were obtained after restricting the analyses to women who had planned the pregnancy or those who were nulliparous before the cohort pregnancy.
Women with RA onset prior to conception had a slightly longer TTP compared with those who did not have RA, indicating a slight reduction in fecundity.