Recurrent spontaneous abortion (RSA), defined as 2 or more consecutive pregnancy losses before 20-22 weeks of gestation, is a multifactorial disorder that affects about 5% of all couples.In up to 50% of women who have experienced RSA, the cause still remains unexplained, with genetic problem proposed as a main cause. X chromosome inactivation (XCI) is a physiological phenomenon in female mammals for 'dosage compensation' of X-linked genes with males. A normal female is mosaic, with about one-half of her somatic cells expressing the paternal derived X and the remainder of her cells using maternal X. In some situations, however, the inactivation is not random, resulting in a female having most or even all her somatic cells inactivating the same X chromosome from either paternal or maternal resource, which is known as skewed X-chromosome inactivation (SXCI).Evidence of an association between skewed X chromosome inactivation (SXCI) and idiopathic recurrent spontaneous abortion (RSA) is conflicting. This is a single-center observational case-control trial to determine whether there is higher incidence of skewed X chromosome inactivation(SXCI) in the recurrent miscarriage(RM) population compared with normal population, and verify the existing hypothesis of the possible genetic mechanisms underlying the association between SXCI and RM.
To determine whether there is higher incidence of skewed X chromosome inactivation(SXCI) in the recurrent miscarriage(RM) population compared with normal population, and verify the existing hypothesis of the possible genetic mechanisms underlying the association between SXCI and RM.