Prenatal Testing
Everyone hopes for a healthy baby. However, most parents-to-be cannot help but to have occasional worries about their developing baby. Fortunately, prenatal tests are available to put your mind at ease. The purpose of these vital tests is to screen for and to diagnose any problems that may affect you or your baby. This process of testing helps to keep you informed throughout your pregnancy about your baby's growth and development as well as your own personal health.
Many prenatal tests and techniques are performed during pregnancy and this can be quite confusing. Some prenatal tests are routinely performed on all women at specific times throughout pregnancy, while others are performed only on women considered to be high-risk based on age, lifestyle, personal or family history. The following list is a quick overview of some of the most common routine and screening tests you should expect and/or may receive during your pregnancy.
FIRST TRIMESTER TESTS (0-12 weeks)
Bloodwork/Cultures/Pap Smear (First Prenatal Visit): Performed on all pregnant women
Hemoglobin/Hematocrit: This checks to see if you are anemic. If the levels are low, you may need iron supplementation and/or increased intake of iron-rich foods.
Urinalysis/Urine Culture: This checks for a bladder infection. If an infection is present, you will be treated with antibiotics to avoid a more serious infection of the kidney.
Blood Type/Rh Factor: This checks your blood type. If your blood is Rh negative and your partner's is Rh positive, you may develop antibodies that can harm your baby. This can be prevented through a course of injections given to you during and after pregnancy.
Rubella (German Measles) Status: This checks to see if you are immune to Rubella disease. Most women have been vaccinated in childhood and are indeed immune. However, if you are not, you will need vaccination after delivery to protect future pregnancies. Rubella infection during pregnancy could lead to still birth, miscarriage or serious birth defects.
Hepatitis B Testing: This checks to see if you have been exposed to Hepatitis. Many women can pass this disease to their baby even if they have no symptoms. If this test is positive, your baby will be given an injection and a vaccination after birth.
Syphillis/Gonorrhea/Chlamydia Testing: This checks for specific sexually transmitted infections that can cause serious birth defects. If you test positive, you and your partner will be treated with antibiotics.
HIV Testing: This checks for the virus that causes AIDS. If you test positive, you will be offered treatment, which greatly reduces the chance that your baby will become infected.
Pap Smear: This checks for precancerous cells or cervical cancer. If detected, you will be offered therapeutic options based on the severity.
Cystic Fibrosis: This checks for the hereditary respiratory disease, CF, that causes breathing and digestion problems. This test is now routinely offered even when there's no family history of the disorder.
First Trimester Genetic Screening (11-14 wks): Offered to all pregnant women. This is a screening test that is used to check for Down syndrome and other chromosomal abnormalities. A blood test as well as an ultrasound is obtained. During the ultrasound, the fluid underneath the skin fold along the back of your baby's neck (nuchal fold) is measured. The combination of these two tests may help to identify pregnancies at risk. If abnormal, an amniocentesis or CVS may be offered to determine if a true problem exists.
Chorionic Villi Sampling (9-12 wks): Offered to certain pregnant women. This is an invasive diagnostic genetic test that may diagnose chromosomal abnormalities or fetal disorders. Using a needle, cells are carefully removed from your placenta and the DNA of these cells is then checked for the presence of chromosomal disorders. This procedure carries a risk of miscarriage.
SECOND TRIMESTER TESTS (13-23 weeks)
QUAD (15-20 wks): Offered to all pregnant women. This is a screening test used to detect the possibility of chromosomal abnormalities or neural tube defects. It is a blood test and if it is positive, an amniocentesis and/or detailed ultrasound is offered.
Ultrasound (18-20 wks): Performed on all pregnant women. This procedure will check the anatomy of your baby and check for physical abnormalities. Ultrasounds may also be used at other times during your pregnancy to confirm your due date, to detect a problem or to monitor a condition of your developing baby.
Amniocentesis (15-18 wks): Offered to certain pregnant women. This is an invasive diagnostic genetic test that may diagnose chromosomal abnormalities such as Down syndrome, neural tube defects and/or certain genetic disorders. It is typically offered to those patients who have abnormal QUAD test results or to women who are advanced maternal age (over 35). Using a needle, cells are carefully removed from the baby's amniotic fluid and the DNA of these cells is then checked for the presence of disorders. This procedure carries a risk of miscarriage.
THIRD TRIMESTER TESTS (24-42 weeks)
Glucose Tolerance Test (24-28 wks): Performed on all pregnant women. This is a one hour glucose screening test that is used to check for gestational diabetes, a condition developed by some women only during pregnancy. If this test is abnormal, a three hour glucose test is performed to confirm the diagnosis. Gestational diabetes may cause health problems with your baby if not diagnosed and/or treated. This condition usually resolves after delivery but the chance of developing permanent diabetes later in life remains.
Group B streptococcus (GBS) infection (35-37 wks): Performed on all pregnant women. The test involves swabbing the vagina and the rectum. It is used to check for GBS which is a common bacteria naturally found in the birth canal that can cause serious infections in newborns during the birthing process. If the culture is positive, you will be given intravenous antibiotics during labor. The antibiotics may reduce the likelihood of your baby becoming infected.
