LAUSR

We read with great interest the article “Poor maternal and foetal outcomes in women with systemic sclerosis: an interview-based study at a tertiary centre” by Kharbanda et al. [1]. It is the first study comparing the maternal and foetal outcomes in women with systemic sclerosis (SSc) to those of patients with systemic lupus erythematosus, idiopathic inflammatory myositis, and Takayasu arteritis. Moreover, the study analyzed the outcomes of pregnancies before and after disease onset. In our opinion, certain points need clarification. First of all, patients’ data were collected by phone call, filling up a case record form. It is not the first study using this strategy [2–4], and, as the authors stated in the discussion, this bias was reduced by reviewing obstetric records shared by WhatsApp or email. However, they did not specify how many patients have sent this information, if all or part of them. Second, the authors do not mention if the different groups were matched based on age or other clinical variables. We are aware that, using an historic cohort, matching would had been hard to achieve, but it would have improved the strength of results. Moreover, only 15 pregnancies occurred after SSc onset and, with such a small number, results must be interpreted with caution. For instance, spontaneous abortions occurred in 3 out of 15 conceptions after SSc onset, but it is not specified if other causes, such as chromosomal abnormalities, had been excluded. Society has evolved and, in present years, late pregnancies, after 40 years of age, are not a sporadic event. Moreover, progressive improvement in assisted reproductive technologies, had notably increased such contingency also in couples with fertility issues. We completely agree with the authors that pregnancies in SSc patients should be considered as high-risk and, therefore, followed in specialized multidisciplinary units. Moreover, as the authors stated in the discussion, a large prospective collaborative multi-centre study assessing the maternal and foetal outcomes in pregnancies of women with SSc is warranted. For instance, a large, multicentre, prospective observational study of pregnancy in SSc (International Multicentric Study on PREgnancy in Systemic Sclerosis, IMPRESS 2) is currently ongoing and definitive results are awaited [5]. Without a solid methodology, drawing conclusions about the effect of SSc on pregnancy and vice versa is like doing a Schrödinger's cat experiment: you cannot infer that the cat is dead or alive until you open the box.