Table 1. Patient Characteristics.

Baseline characteristic	No. (%)
All patients	2557
Age at CIS onset, mean (SD), y	31.5 (9.7)
Initial symptoms
Supratentorial	460 (18)
Optic neuritis	599 (23)
Brainstem or cerebellum	464 (18)
Spinal	525 (21)
Unifocal onset	1371 (54)
Multifocal onset	301 (12)
No information	885 (34)
Proportion of women with information on OCB status
In Czech Republic (n = 1854)	316 (17)
In Australia (n = 703)	138 (20)
EDSS score at CIS onset, median (IQR) (n = 717)a	1.5 (1.0-2.0)
No. of women with pregnancies before CIS onset	1188 (46)
No. of women with childbirths before CIS onset	1100 (43)
No. of women pregnant at time of CIS onsetb	71 (3)
Age, mean (SD), y
At first pregnancy before CIS onset (n = 1188)	23.3 (4.5)
At first childbirth before CIS onset (n = 1100)	23.8 (4.5)
Per woman, median (IQR) [range]
No. of pregnancies before CIS onset	0 (0-2) [0-11]
No. of childbirths before CIS onset	0 (0-2) [0-6]
Duration, mean (SD), mo
Pregnancies before CIS onset (n = 2586)	7.2 (3.2)
Childbirths before CIS onset (n = 1961)	9.0 (0.5)
Per woman, median (IQR)
Total breastfeeding duration before CIS onset, median (IQR), mo	0 (0-5)

Abbreviations: CIS, clinically isolated syndrome; EDSS, Expanded Disability Status Scale (score range: 0.0-6.5, with higher numbers indicating a greater degree of disability); IQR, interquartile range; OCB, oligoclonal bands.

^aAn EDSS assessment was administered within 12 months of CIS onset. Mean (SD) time between CIS onset and EDSS score was 5.2 (3.5) months.

^bSeventy-one women were diagnosed with CIS during pregnancy: 66 had childbirths, 3 had spontaneous miscarriages, and 2 had induced abortions.