Systemic sclerosis, birth order and parity

Abstract

Aim: A recent study identified increasing birth order to be a risk factor for the development of systemic sclerosis (SSc). This finding supports the theory that transplacental microchimerism may be a key pathological event in the initiation of SSc. We investigated the relationship between birth order and parity and the age of onset of SSc in South Australia.Method: A retrospective analysis of patient data in the South Australian Scleroderma Register was performed. Data were obtained from a mailed questionnaire. Control data was collected prospectively using a similar questionnaire. The relationship between birth order, family size or parity and risk of subsequent development of SSc was analyzed by mixed effects logistic regression analysis.Results: Three hundred and eighty-seven index probands were identified and compared with 457 controls. Controls were well matched for gender, but not for age. No statistically significant relationship was identified between SSc and birth order, parity in females, family size, age at first pregnancy in females or gender of first child in parous females. Conclusion:Our data suggests that parity, age at first pregnancy and the gender of the first child are not relevant factors in our understanding of the epidemiology and pathogenesis of SSc. Birth order and family size in both genders also appears irrelevant. These results argue against microchimerism as being relevant in the pathogenesis of SSc and add further support to the theory that stochastic events may be important in the etiopathogenesis of SSc.

A systematic review of the epidemiology, disease characteristics and management of systemic sclerosis in Australian adults

“…The Australian studies of prevalence recruited patients from SA and NSW only, thus their generalizability to the wider Australian population is uncertain. Genetic and shared environmental factors may play a role in this high prevalence, although the studies to date have been inconclusive . In addition, there was only one study focusing on the epidemiology of SSc among the Indigenous population ( n = 5), demonstrating a similar prevalence to non‐Indigenous Australians.…”

“…Genetic and shared environmental factors may play a role in this high prevalence, although the studies to date have been inconclusive. 4,5,19 In addition, there was only one study focusing on the epidemiology of SSc among the Indigenous population (n = 5), demonstrating a similar prevalence to non-Indigenous Australians. This is discordant with the prevalence of other CTDs, such as systemic lupus erythematosus, which has a higher reported prevalence among the Indigenous Australian population.…”

Fetal microchimerism in a pregnant woman and risk of autoimmune disease

“…Retrospektywną analizą objęto 387 pacjentek z SSc oraz 367 zdrowych kobiet. Badacze wykluczyli kolejność urodzenia, wielkość rodziny, liczbę ciąż, wiek pierwszej ciąży oraz płeć pierwszego dziecka jako czynniki istotne w epidemiologii i patogenezie SSc, zaznaczając jednocześnie, że niezbędne jest przeprowadzenie większego badania z dobrze dobraną grupą kontrolną [10].…”

“…However, the theory of fetal MC in SSc was not confirmed in the study by Russo et al The retrospective analysis covered 387 patients with systemic scleroderma and 367 healthy individuals. The authors excluded birth order, family size, parity, age at first pregnancy and the gender of the first child as relevant factors in the understanding of epidemiology and the pathogenesis of SSc, although they admitted that a larger study with a well-matched control population is required [10].…”

The association between reproductive factors and systemic sclerosis in Chinese women: A case‐control study and meta‐analysis

“…Then 3 studies 10,18,19 were excluded and 3 review articles [20][21][22] were also excluded for the absence of sufficient information about menstrual and reproductive factors. Totally, along with our study, 6 case-control studies 9,[11][12][13]23 including 3837 SSc patients and 13 914 controls were finally selected (including those from our own case-control study). The characteristics of the studies are shown in Table 3.…”