Table 2 Effect estimates of the association between pregnancy loss and rheumatoid arthritis risk

 Ever vs. never

1.28 (1.22–1.34)*

1.12 (1.06–1.18)*

 None

2477

1.00 (reference)

1.00 (reference)

 1

2386

1.19 (1.13–1.26)*

1.09 (1.03–1.16)*

 2

1600

1.31 (1.23–1.40)*

1.13 (1.05–1.20)*

 ≥3

1040

1.44 (1.34–1.55)*

1.19 (1.10–1.28)*

 Per additional

1.13 (1.11–1.16)*

1.06 (1.03–1.08)*

 Ever vs. never

1.14 (1.05–1.23)*

1.11 (1.03–1.20)*

 None

6742

1.00 (reference)

1.00 (reference)

 1

593

1.12 (1.03–1.22)*

1.10 (1.01–1.20)*

 2

110

1.05 (0.87–1.27)

1.03 (0.85–1.25)

 ≥3

58

1.58 (1.21–2.06)*

1.50 (1.15–1.96)*

 Per additional

1.10 (1.05–1.16)*

1.09 (1.03–1.15)*

 Ever vs. never

1.24 (1.19–1.30)*

1.11 (1.06–1.17)*

 None

3174

1.00 (reference)

1.00 (reference)

 1

2180

1.18 (1.12–1.25)*

1.09 (1.03–1.16)*

 2

1374

1.29 (1.21–1.37)*

1.14 (1.06–1.22)*

 ≥3

775

1.35 (1.25–1.46)*

1.16 (1.06–1.26)*

 Per additional

1.12 (1.09–1.14)*

1.05 (1.03–1.08)*

 Ever vs. never

1.16 (1.06–1.28)*

1.07 (0.97–1.18)

 None

7013

1.00 (reference)

1.00 (reference)

 1

392

1.20 (1.09–1.34)*

1.11 (1.00–1.23)

 2

75

1.10 (0.87–1.38)

0.97 (0.77–1.23)

 ≥3

23

0.84 (0.55–1.26)

0.74 (0.49–1.13)

 Per additional

1.07 (1.01–1.15)*

1.01 (0.94–1.08)