Genetic Testing & Health Screenings
Genetic tests during pregnancy are used to screen for genetic diseases and disorders. Some of the diseases that genetic testing measures are Down's syndrome, which delays physical and mental development, Tay-Sachs disease, a fatal illness that destroys nerves in the brain, sickle-cell anemia, a disease in which the red blood cells are abnormally shaped, cystic fibrosis, a gland disease that results in lung damage, and spina bifida, in which the spine is not fully developed. Women choose to have genetic testing for a variety of reasons, one of which may simply be their own peace of mind, though the more invasive the test, the more likely there may be complications.
Risks for Genetic Disorders
Women who are at risk for giving birth to babies with genetic disorders, and who may want to consider genetic testing, include women who are older than 35 years of age, women who have given birth before to a child with a genetic disorder, and women who have a family history of genetic disorders.
Types of Genetic Testing
The types of genetic testing can be grouped in several ways. Some merely screen the fetus for potential genetic abnormalities, and others are used for a diagnosis. Amniocentesis is one example of a diagnostic genetic test that you may undergo. This is an invasive test, which carries a small risk of miscarriage, according to expectantmothersguide.com http://www.expectantmothersguide.com/library/cleveland/prenatal-genetic-testing.htm. Non-invasive tests include ultrasounds and blood tests.
First Trimester Genetic Testing
If you decide to have genetic testing, in your first trimester, your baby will be tested for Down's syndrome using a blood test and an ultrasound. Tissue thickness and hormone and protein levels are measured. For diagnostic testing, a pregnant woman may have a chorionic villus sampling done, in which a tube is used, through insertion into the cervix, to gather chromosomes from the placenta and the baby for further examination.
Second Trimester Genetic Testing
In your second trimester, you may have quad testing done. This blood test looks at liver function of the fetus, and the hormones and proteins made by the placenta, and evaluates whether they are too high or too low. Diagnostic testing includes amniocentesis, which can check for spina bifida in a baby. In this test, a needle gathers amniotic fluid, which contains fetal cells, through a small incision in the abdomen. A comprehensive ultrasound can also be done. This ultrasound looks to see if the fetus could have exterior defects such as a cleft palate.
Complications of Genetic Testing
It is important for mothers to remember that if they receive unfavorable results on a screening test, that does not necessarily mean that their child will have a genetic disorder. Likewise, if the screening is clear, that does not mean the child will not have a genetic disorder. If a pregnant woman wants to be certain of her baby's health, she will have to undergo a diagnostic test. However, diagnostic testing carries certain risks to the health of the baby and the mother. According to birth.com http://www.birth.com.au/Genetic-Testing/Genetic-testing-about.aspx?p=2, these risks include uterine infection, internal bleeding, miscarriage, and fetal injury. Women should consider the dangers of diagnostic genetic testing carefully, because the potential exists for her to do damage to a healthy baby.