Page 64 - Fertility in Women with Rheumatoid Arthritis Vruchtbaarheid van vrouwen met reumatoïde artritis

Chapter 4
PATIENTS AND METHODS
Patients
This study was performed within the Pregnancy-induced Amelioration of RA (PARA) study, a nationwide prospective cohort study in the Netherlands.1 From 2002 to 2008, RA patients who wanted to become pregnant or were in their rst trimester of pregnancy were invited by their attending rheumatologist to participate. Patients had to ful ll the American College of Rheumatology 1987 revised criteria.11 According to current guidelines, patients were required to have stopped teratogenic medications, such as methotrexate (MTX), at least 3 months before trying to conceive to be eligible for the study. Informed consent was acquired from all patients. The study was approved by the Erasmus Medical Center medical ethics review board.
For the current study, all patients who were enrolled preconceptionally were included. If patients participated at least twice in the PARA study, only the rst episode was included.
Data
During the study, patients were visited preconceptionally, during each trimester of pregnancy, and 3 times (6, 12, and 26 weeks) after delivery. When patients miscarried, they were also visited at 6, 12, and 26 weeks following their pregnancy loss. Pregnancies were con rmed by the patients with a positive urine pregnancy test result. Miscarriage was de ned as a loss of pregnancy before 16 completed weeks of gestation.
At each visit, patients were interviewed by a research team member to obtain information on obstetric history and medication use. The level of disease activity was measured using the Disease Activity Score in 28 joints (DAS28)12 based on 3 variables: the swollen, tender joint count, and C-reactive protein (CRP) level.1
To determine the change in disease activity after miscarriage, we calculated the difference between the preconception DAS28 and DAS28 at 6, 12, and 26 weeks after miscarriage. We de ned deterioration of RA as severe or moderate flares, de ned as a reverse improvement response according to the European League Against Rheumatism response criteria for disease activity,13 which is independent of the baseline DAS28.1
Finally, levels of CRP, presence of rheumatoid factor (RF) and presence of anti- citrullinated protein antibodies (ACPAs) were determined, as described previously.2
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