Time to pregnancy in women with rheumatoid arthritis who want to conceive treated according to a treat-to-target approach: a comparison of an observational cohort with a historical reference cohort.

Abstract

Time to pregnancy is prolonged in women with rheumatoid arthritis. Rheumatoid arthritis-related factors that influence time to pregnancy include high disease activity, high daily prednisone intake (exceeding 7·5 mg), and non-steroidal anti-inflammatory drug (NSAID) use. The aim of this study was to investigate whether a treat-to-target approach aimed at remission, while avoiding NSAIDs and high doses of prednisone, was associated with a reduced time to pregnancy in women with rheumatoid arthritis who wanted to conceive. This comparative study used data from a prospective observational cohort of patients treated with a treat-to-target approach and a historical prospective observation cohort that did not use this approach. Cases were derived from Preconception Counseling in Active Rheumatoid Arthritis (PreCARA; September, 2011, to September, 2023) and controls from Pregnancy-Induced Amelioration of Rheumatoid Arthritis (PARA; May, 2002 to August, 2010). Both studies were conducted at the Erasmus University Medical Center in The Netherlands and women with rheumatoid arthritis who wanted to conceive or were already in their first trimester were eligible. In PreCARA, participants were managed according to treat-to-target principles adapted for pregnancy. The treat-to-target approach avoided NSAIDs and prednisone use over 7·5 mg per day and medication compatible with pregnancy was provided (eg, TNF inhibitors). The primary outcome was the occurrence of pregnancy and time to pregnancy in all participants, calculated as the duration between the date of the first attempt to conceive and the first day of the last menstrual period before pregnancy. People with lived experience were involved in the design of both PreCARA and PARA. 215 patients from PreCARA and 245 patients from PARA were included. The mean age in PreCARA was 32·4 years (SD 4·2) and in PARA it was 31·8 years (3·9). Patients in PreCARA had a median time to pregnancy of 91 days (IQR 27-333), compared with 251 days (IQR 97-554) in the PARA cohort (p<0·0001). 165 (77%) of 215 patients in PreCARA got pregnant within 1 year versus 103 (42%) of 245 patients in PARA (p<0·0001). 131 (61%) of 215 patients in PreCARA reached clinical remission. Their median time to pregnancy was 65 days (IQR 19-295), compared with 150 days (IQR 49-575) in patients in PreCARA who did not reach remission (p=0·0054). This study showed that, in women with rheumatoid arthritis treated according to a treat-to-target strategy, time to pregnancy was reduced and was close to that of the general population. Dutch Arthritis Foundation and UCB.