Prenatal care is essential to ensure the healthy growth and development of a fetus. Women who receive prenatal care have healthier babies, are less likely to deliver prematurely, and have fewer pregnancy-related problems. Prenatal care should begin as early as possible. Doctor visits are usually monthly, and become more frequent as the pregnancy progresses. Routine tests at these visits include urine testing and blood-pressure checks. In addition to routine tests, there are several prenatal tests that are performed at specific times during the pregnancy. They are administered to monitor the health of the fetus and, in some cases, the mother.
Types of Prenatal Tests
A variety of prenatal tests are performed to monitor the fetus‘s health, and identify anything that can lead to complications. Certain tests are administered at different times throughout the pregnancy. After initial blood and urine tests to confirm a pregnancy, additional prenatal tests often include those below.
Genetic Carrier Screening-Horizon
Horizon carrier screening is a simple blood test that checks to see if you are a carrier of one or more autosomal recessive or X-linked genetic conditions. Having carrier screening allows you to make more informed reproductive decisions by helping you understand your carrier status. If you are a carrier for any genetic condition, your partner can also be tested to determine likelihood of your fetus having the condition.
Non-Invasive Prenatal Testing (NIPT) Panorama
Cell-Free DNA Testing
Cell-free DNA testing is a noninvasive way of testing a fetus‘s DNA by using the mother‘s blood. It can be performed anytime after 10 weeks of pregnancy, and is used as a screening tool to determine whether the fetus has genetic conditions such as Down syndrome and Trisomy 18. It can also determine the sex of the fetus.
Nuchal Translucency Screening
Nuchal translucency screening is commonly performed at 11 to 14 weeks of pregnancy. An ultrasound is used to measure the thickness of the back of the fetus‘s neck. The information obtained from the ultrasound, in conjunction with a blood test, is used to determine whether Down syndrome is present.
Chorionic Villus Sampling
Chorionic villus sampling (CVS) is and invasive test performed at 10 to 12 weeks of pregnancy. It is used to determine whether the fetus has a genetic condition such as Down syndrome. During the test, a sample of chorionic villi is removed from the placenta for testing. An ultrasound may be performed in conjunction with this test to guide the physician as the tissue sample is removed.
The alpha-fetoprotein (AFP) test examines the level of alpha-fetoprotein in the mother‘s blood during pregnancy. This test is commonly performed between the 14th and 18th weeks of pregnancy. A blood sample is taken from the mother to measure the AFP levels in her blood, which may be an indicator of certain genetic conditions or birth defects.
A detailed fetal ultrasound is commonly performed at 18 to 20 weeks of pregnancy. This ultrasound will be performed at an imaging center and will detail all parts of the fetus, from the heart, to the bladder, to the mouth and nose and beyond. It will also monitor the fetus‘s growth and development, and determine how the pregnancy is progressing.
Amniocentesis is an invasive test that can be performed between 16 to 20 weeks of pregnancy to determine whether the fetus has Down syndrome or another genetic condition. During the test, a thin needle is inserted into the mother‘s abdomen to suction out a small amount of tissue and cells from the amniotic fluid that surrounds the fetus. It is usually only performed if the mother has a high risk of having a child with a genetic condition, or is at an advanced age for pregnancy.
Glucose screening is performed at 28 weeks of pregnancy in our office; it is used to test for gestational diabetes. The mother consumes a sugary drink, and her blood is tested an hour later to measure her blood-sugar levels.
Group B Streptococcus Infection Screening
Group B Streptococcus infection screening is often performed around 36 weeks of pregnancy. It is used to determine the presence of any streptococcus bacteria, which can cause serious infections in the fetus. Swabs are used to take samples from the mother‘s vagina and rectum. A woman who tests positive for this bacteria will need antibiotics when she is in labor.
Urine testing is performed throughout the pregnancy to test for diabetes, preeclampsia and infection.