Genetic testing helps determine whether a person’s genes or chromosomes are linked to a health problem; it can also identify changes in a person’s genes. The procedure can be done before, during or after pregnancy.
WHO SHOULD CONSIDER GENETIC TEST?
You may consider genetic testing if:
- If you or your partner are at risk of having a genetic condition (such as cystic fibrosis)
- You or your partner have a chromosomal disorder or have a child with a chromosomal problem (such as Down syndrome)
- If you are over 35 (for women) and therefore you have a higher risk of having a child with a chromosomal disorder due to your age.
GENETIC TESTS BEFORE PREGNANCY
Embryos created using in vitro fertilization (IVF) can be tested for a specific genetic condition before being transferred to the womb. This test is called preimplantation genetic diagnosis (PGD). If the test shows that the embryos carry a genetic condition, these embryos are not usually transferred.
ADVANTAGES OF PGD
PGD is very accurate and is the earliest way to detect a genetic or chromosomal condition before birth. Finding a genetic condition through PGD can help with decision making. Because genetic and chromosomal conditions often cause natural abortions, PGD can also increase the chances of pregnancy and live birth.
DISADVANTAGES OF PGD
PGD is usually only performed if the genetic alteration for the particular condition has already been found in one or both partners through previous genetic testing. PGD is intended to detect specific genetic conditions. However, tests may reveal an unexpected chromosomal problem in the embryo that has nothing to do with family history. The costs of PGD are often added to the costs of fertility treatments and are tied to the specific test. PGD does not guarantee that an embryo will be implanted or that a full-term pregnancy will result. It may still be low.
GENETIC SCREENING AND TESTING IN PREGNANCY
Prenatal screening is done before the baby is born. It detects pregnancies that are more likely to be affected by a chromosomal condition (such as Down syndrome) or birth defects (such as Spina bifida). The screening test can only estimate the risk and cannot confirm whether the developing fetus has one of these conditions.
Some screening options include: Integrated prenatal screening (IPS), first trimester screening (FTS), maternal serum screening, and obstetric ultrasound. Prenatal genetic testing means testing the fetus for genetic changes. Options include amniocentesis and chorionic villus sampling (CVS). Amniocentesis is usually done between 15-18 weeks of pregnancy. done between weeks. CVS is usually between 10 and 12 weeks of pregnancy. done between weeks. Most babies are born healthy. But genetic conditions and birth defects occur in at least 3 percent of pregnancies, either naturally or through fertility treatments.