Miscarriage and Its Associations

Stephen Brown, M.D.


Semin Reprod Med. 2008;26(5):391-400. 

In This Article

X-Chromosome Inactivation Skewing

In females, one of the two X chromosomes is inactivated in early embryonic life, a process that generally occurs randomly. X chromosome inactivation skewing occurs in situations in which there is a cellular survival advantage associated with one of the two Xs remaining active. Structural abnormalities of the X chromosome or the presence of a dominantly acting lethal mutation are examples of when this might occur. A relatively recent development has been the purported association with skewed (or nonrandom) X-chromosome inactivation with miscarriage, although the possible biological basis for such an association has not been clear. Earlier reports seemed to show a strong association,[44,45,46] whereas later reports have not.[47] Overall, it seems that this association is weak at best.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.