age risk downs pregnancy
The main factor that increases the chance of having a baby with Down's syndrome is the age of the woman when she becomes pregnant. For example, a woman who is: 20 years of age has a chance of one in 1,500. 30 years of age has a chance of one in 800. 35 years of age has a chance of one in 270. A woman's risk of having a baby with chromosomal abnormalities increases with her age. Down syndrome is the most common chromosomal birth defect, and a woman's risk of having a baby with Down syndrome is: At age 20, 1 in 1,441. At age 25, 1 in 1,383. At age 30, 1 in 959. Increased maternal age can increase your child's risk of certain conditions. Down Syndrome. A woman is born with all of the eggs she will ovulate with for the rest of her life. So if you're 30 when you conceive, then the egg you conceived with is also 30 years old. If you are 45 when you conceive, then the egg you conceive with is 45 years old. As eggs age, the more likely they are to have errors that can result in trisomies, including trisomy 21 (Down syndrome). At the age of 35, your risk of having a baby with a chromosomal problem is about 1 in 200 and the risk to have a miscarriage from an amniocentesis was thought to be about 1 in 200. Since these rates were considered to be the same, 35 was picked as the recommended starting age for diagnostic testing. The factors that place a pregnancy at risk can be divided into four categories: 1  Existing Health Conditions. 2  Age. 3  Lifestyle Factors.  Conditions of Pregnancy. Multiple gestation. Pregnancy with twins, triplets, or more, referred to as a multiple gestation, increases the risk of infants being born prematurely (before 37 weeks of pregnancy). Having infants after age 30 and taking fertility drugs both have been associated with multiple births. The likelihood of Down Syndrome continues to increase as a woman ages, so that by age 42, the chance is one in 60 that a pregnant woman will have a baby with Down syndrome, and by age 49, the chance is one in 12. If a patient has had a trisomy 21 pregnancy in the past, the risk of recurrence in a subsequent pregnancy increases to approximately 1 percent above the baseline risk determined by maternal age. Diagnosis of a chromosome-21 translocation in the fetus or newborn is an indication for karyotype analysis of both parents. At age 45, the risk of a having a child with Down syndrome increases to 1/30. (By convention, maternal age refers to age at the estimated or actual delivery date.) Historically, maternal age can be viewed as the first “screening test” for fetal chromosome abnormalities. Down syndrome (trisomy 21) is the most commonly recognized genetic cause of mental retardation. The risk of trisomy 21 is directly related to maternal age. All forms of prenatal testing for Down syndrome must be voluntary. This is because older mothers tend to have fewer babies. The likelihood that a woman under age 30 who becomes pregnant will have a baby with Down syndrome is less than one in 1,000, but the chance of having a baby with Down Syndrome increases to 1 in 400 for women who become pregnant at age 35.
A woman's risk of having a baby with Down syndrome is: At age 20, 1 in 1,441. At age 25, 1 in 1,383. At age 30, 1 in 959.