Fast Facts
- Up to 1 in 5 pregnancies ends in loss; however, with time most couples go on to have healthy pregnancies after loss
- 1-2% of couples experience recurrent miscarriage, or the loss of multiple pregnancies before the 20th week
- For 50% of couples who experience multiple miscarriages, the underlying reason remains unexplained.
- Known causes of recurrent miscarriage include: anatomic abnormalities of the uterus; autoimmune, endocrine or other medical conditions; chromosomal abnormalities; and lifestyle or environmental factors.
Definition of Recurrent Pregnancy Loss
A pregnancy loss is devastating no matter when it occurs; however, definitions matter for diagnostics and medicine. The American Society for Reproductive Medicine defines recurrent pregnancy loss as the loss of two or more clinical pregnancies before the 20th week. But what exactly does this mean?
- A "clinical pregnancy" is one which has been confirmed by both an ultrasound and blood test. If a loss occurs after a positive urine or blood test, but before an ultrasound, it will be referred to as a "chemical pregnancy." This does not mean that chemical pregnancies don't count, and in fact many doctors will recommend full workups after three losses of any kind. But doctors may consider different factors or treatments depending on when losses occur.
- 20 weeks is the US line of demarcation between a "miscarriage" and a "stillbirth." In addition, an "embryonic loss" is a loss which occurs before 9 weeks and a "fetal loss" is a loss which occurs after 9 weeks but before 20 weeks
Known and Unknown Causes
A known cause, or "etiology" can be identified many families experiencing RPL. Those causes are depicted on the right side of the image below and discussed on the Causes and Treatments page.
However, in roughly 50% of cases, the cause of RPL is unknown, or "idiopathic." The depictions on the left side of the image represent factors that have been associated with recurrent miscarriage, but require more study.
Reprinted by permission from Springer Nature: Springer US, Journal of Assisted Reproduction and Genetics, "Genetic and Epigenetic Variations Associated with Idiopathic Recurrent Pregnancy Loss," Luis Alejandro Arias-Sosa et al, © 2018
Sources
- Rev Obstet Gynecol. 2009 Spring; 2(2): 76–83.
- Fact Sheet: What is Recurrent Pregnancy Loss? 2016 Revision. American Society for Reproductive Medicine. www.reproductivefacts.org
- Arias-Sosa, Luis Alejandro, et al. “Genetic and Epigenetic Variations Associated with Idiopathic Recurrent Pregnancy Loss.” Journal of Assisted Reproduction and Genetics, Springer US, 2018, www.ncbi.nlm.nih.gov/pubmed/29313278
NIAW 2021
It's National Infertility Awareness Week (NIAW) and we're raising awareness for the 1-2% of couples for who experience recurrent pregnancy loss.
Our goal is to raise $5,000 during NIAW to support our research grant program and we'd love your help.