Recurrent pregnancy loss (RPL) is defined as three or more consecutive pregnancy losses before the 20th week of gestation.
Although there can be many causes of RPL, genetic cases are overwhelmingly the most common, making up approximately 90% of recurrent losses. Of these, 60-80% are caused by recurrent aneuploidy (extra or missing chromosome, such as Down Syndrome, Trisomy, and Turner Syndrome). In 15% of cases, microdeletions of the X chromosome causes skewing of the pattern of inactivation, causing a 25% loss of male offspring. Recent evidence from microarray testing suggests that a small percentage of RPL are due to chromosomal microdeletions or insertion (a chromosome missing or having an extra small piece of DNA).
There are also non-genetic causes of RPL from specific medical conditions. Severe cases of diabetes and hypothyroidism are associated with recurrent loss, but subclinical varieties of these disorders are not. The association between most medical conditions and RPL are controversial with little supporting evidence. These conditions include infections such as mycoplasma and ureaplasma, as well asluteal phase defects.
The association of inherited and acquired thrombophilias (blood clotting disorders) with RPL is also controversial. A number of authors have reported an association, while many others have not. The studies make an unclear connection between thrombophilias and early pregnancy loss, but there are potential associations between thrombophilias and late fetal loss (second trimester)..
For patients with RPL, it is important to have a thorough evaluation to determine any potential causes of RPL, as well as the options for therapy.
Maternal Fetal Medicine blogs are intended for educational purposes only and do not replace certified professional care. Medical conditions vary and change frequently. Please ask your doctor any questions you may have regarding your condition to receive a proper diagnosis or risk analysis. Thank you!