From the Research
Yes, X chromosome loss in women can cause miscarriage, as supported by the most recent and highest quality study available 1. When a woman loses an X chromosome in her eggs or in the developing embryo, it often results in a condition called Turner syndrome (45,X), where only one X chromosome is present instead of the normal two sex chromosomes. Most pregnancies with Turner syndrome (approximately 99%) end in spontaneous miscarriage, typically during the first trimester, as reported in various studies, including 2 and 1. This high rate of pregnancy loss occurs because the X chromosome contains essential genes needed for fetal development. While some Turner syndrome pregnancies do survive to term, they represent only about 1% of all Turner syndrome conceptions. The severity of the impact depends on when and in which cells the X chromosome loss occurs. If the loss happens after fertilization, it may result in mosaic Turner syndrome, which can have varying effects depending on the proportion of cells affected. The critical genes on the X chromosome are necessary for proper organ development, particularly the heart and lymphatic system, which explains why their absence often leads to developmental abnormalities incompatible with life, resulting in miscarriage, as discussed in 3 and 4. Key points to consider include:
- The frequency of chromosomal abnormalities, including X chromosome loss, increases with maternal age, as shown in 1.
- Cytogenetic analysis of products of conception (POC) is recommended for women with a history of miscarriage or normal live birth history, as suggested in 1.
- The mode of conception, whether natural or assisted, may also influence the frequency of chromosomal abnormalities, including X chromosome loss, as reported in 1. Given the potential for X chromosome loss to cause miscarriage, it is essential to consider cytogenetic analysis and genetic counseling for women experiencing recurrent miscarriages or those with a history of Turner syndrome in their family 1.