Risk factorsBy Mayo Clinic Staff
Some parents have a greater risk of having a baby with Down syndrome. Risk factors include:
April 19, 2014
- 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 about 1 in 350. By age 40, the risk is about 1 in 100, and by age 45, the risk is about 1 in 30. However, most children with Down syndrome are 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 in 100 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.
- What is Down syndrome? National Down Syndrome Society. http://www.ndss.org/Down-Syndrome/What-Is-Down-Syndrome/. Accessed Nov. 14, 2013.
- Down syndrome fact sheet. National Down Syndrome Society. http://www.ndss.org/Down-Syndrome/Down-Syndrome-Facts/. Accessed Nov. 14, 2013.
- Learning about Down syndrome. National Human Genome Research Institute. http://www.genome.gov/19517824. Accessed Nov. 14 2013.
- Down syndrome. Genetics Home Reference. http://ghr.nlm.nih.gov/condition/down-syndrome. Accessed Nov. 14, 2013.
- Facts about Down syndrome. Centers for Disease Control and Prevention. http://www.cdc.gov/ncbddd/birthdefects/DownSyndrome.html. Accessed Nov. 13, 2013.
- Ostermaier KK. Down syndrome: Clinical features and diagnosis. http://www.uptodate.com/home. Accessed Nov. 14, 2013.
- Messerlian GM, et al. Overview of prenatal screening and diagnosis of Down syndrome. http://www.uptodate.com/home. Accessed Nov. 14, 2013.
- American College of Obstetricians and Gynecologists (ACOG) Committee on Practice Bulletins — Obstetrics. ACOG Practice Bulletin No. 77. Screening for fetal chromosomal abnormalities. Obstetrics & Gynecology. 2007;109:217. Reaffirmed 2011.
- Frequently asked questions. Pregnancy FAQ094. Genetic disorders. American College of Obstetricians and Gynecologists. http://www.acog.org/~/media/For%20Patients/faq094.pdf?dmc=1&ts=20131118T2245557486. Accessed Nov. 14, 2013.
- How do health care providers diagnose Down syndrome? Eunice Kennedy Shriver National Institute of Child Health and Human Development. https://www.nichd.nih.gov/health/topics/down/conditioninfo/Pages/diagnosed.aspx. Accessed Nov. 18, 2013.
- Ghidini A. Chorionic villus sampling: Risks, complications, and techniques. http://www.uptodate.com/home. Accessed Dec. 4, 2013.
- Hoecker JL (expert opinion). Mayo Clinic, Rochester, Minn. Dec. 5, 2013.
- Patterson MC (expert opinion). Mayo Clinic, Rochester, Minn. Dec. 22, 2013.
- Harms RW (expert opinion). Mayo Clinic, Rochester, Minn. Jan. 16, 2014.
- American College of Obstetricians and Gynecologists Committee on Genetics. Committee Opinion No. 545: Noninvasive prenatal testing for fetal aneuploidy. Obstetrics & Gynecology. 2012;120:1532.
- Second trimester: Cordocentesis (percutaneous umbilical blood cord sampling, PUBS). Lab Tests Online. http://labtestsonline.org/understanding/wellness/pregnancy/second-trimester/cordo/. Accessed Jan. 17, 2014.