Relationship between parity and clinical and biological features in patients with systemic sclerosis

To assess the influence of parity on the clinical and biological features of systemic sclerosis (SSc).

We recorded the following clinical and biological data of 100 consecutive women with SSc: age, disease duration before diagnosis, cutaneous extension of sclerosis according to LeRoy's classification, pulmonary involvement, and antinuclear antibodies. We compared these features to the number and sex of children who were born before SSc onset. Date of birth of the first children was systematically recorded.

Patients with limited SSc had more children before SSc onset than patients with diffuse SSc (2.4 +/- 1.8 vs 1.7 +/- 1.5; p < 0.05). The interval between first birth and SSc onset was shorter for patients with limited SSc than for patients with diffuse SSc (11.0 +/- 9.9 vs 23.5 +/- 14.5 yrs; p < 0.01). Patients with pulmonary fibrosis had more children than patients without pulmonary fibrosis (2.5 +/- 1.9 vs 2.0 +/- 1.6; p < 0.05). Age at first birth was significantly higher when the child was a girl than a boy (26.8 +/- 7.5 vs 22.9 +/- 5.3 yrs; p < 0.05). The interval between the first birth and SSc onset was shorter when the child was a girl than a boy (16.2 +/- 9.6 vs 25.4 +/- 13.4 yrs; p < 0.05).

Pregnancy related microchimerism could be preferentially associated with limited SSc and pulmonary fibrosis. Microchimerism may be facilitated in cases in which the fetus is female.