Free
E-newsletter
Subscribe to Housecall
Our weekly general interest
e-newsletter keeps you up to date
on a wide variety of health topics.
close window
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Risk factors
By Mayo Clinic staffSome parents have a greater risk of having a baby with Down syndrome. Risk factors include:
- Advancing maternal age. A woman's chances of giving birth to a child with Down syndrome increase with age because older eggs have a greater risk of improper chromosome division. By age 35, a woman's risk of conceiving a child with Down syndrome is 1 in 400. By age 45, the risk is 1 in 35. However, most children with Down syndrome are actually born to women under age 35 because younger women have far more babies.
- Having had one child with Down syndrome. Typically, a woman who has one child with Down syndrome has about a 1 percent chance of having another child with Down syndrome.
- Being carriers of the genetic translocation for Down syndrome. Both men and women can pass the genetic translocation for Down syndrome on to their children.
References
- Facts about Down syndrome. National Institute of Child Health and Human Development. http://www.nichd.nih.gov/publications/pubs/downsyndrome.cfm. Accessed Feb. 14, 2011.
- Barss V, et al. Overview of prenatal screening and diagnosis of Down syndrome. http://www.uptodate.com/home/index.html. Accessed Feb. 14, 2011.
- Esbensen AJ. Health conditions associated with aging and end of life of adults with Down syndrome. International Review of Research in Mental Retardation. 2010;39:107.
- What causes Down syndrome? National Down Syndrome Society. http://www.ndss.org/index.php?option=com_content&task=category§ionid=23&id=60&Itemid=234. Accessed Feb. 14, 2011.
- Genetic conditions: Down syndrome. Genetics Home Reference. http://ghr.nlm.nih.gov/condition=downsyndrome. Accessed Feb. 14, 2011.
- ACOG practice bulletin no. 77: Screening for fetal chromosomal abnormalities. Obstetrics and Gynecology. 2007;109:217.
- Birth defects: Down syndrome. Centers for Disease Control and Prevention. http://www.cdc.gov/ncbddd/birthdefects/DownSyndrome.htm. Accessed Feb. 15, 2011.
- Roizen NJ. Clinical features and diagnosis of Down syndrome. http://www.uptodate.com/home/index.html. Accessed Feb. 15, 2011.
- Birth defects. In: American College of Obstetricians and Gynecologists. Your Pregnancy and Childbirth Month to Month. 5th ed. Washington, D.C.: American College of Obstetricians and Gynecologists; 2010:343.
- Harms RW (expert opinion). Mayo Clinic, Rochester, Minn. Feb. 15, 2011.
- Chiu RWK, et al. Non-invasive prenatal assessment of trisomy 21 by multiplexed maternal plasma DNA sequencing: Large scale validity study. British Medical Journal. 2011;342:7401.
Find Mayo Clinic on