Pregnancy Test
A pregnancy test can tell whether you're pregnant by checking a sample of your urine (pee) or blood for a hormone called human chorionic gonadotropin (hCG).
A pregnancy test can tell whether you're pregnant by checking a sample of your urine (pee) or blood for a hormone called human chorionic gonadotropin (hCG). This hormone is made by the placenta, the organ that grows in your uterus to provide oxygen and nutrients to the fetus. The placenta starts making hCG after a fertilized egg attaches to the inside wall of your uterus. Levels then continue to rise for ten weeks, almost doubling every three days. hCG helps your body prepare for pregnancy by: Telling your body to produce progesterone, which thickens the lining of your uterus. Telling your body to produce estrogen, which prepares your body for labor and helps your fetus develop. Stopping your menstrual periods . There are two types of pregnancy tests: Urine tests , which can be done at your health care provider's office or with an at-home test kit. These tests are 97-99% accurate when done a week or two after you've missed your period and can give you the results quickly. If you do an at-home test, follow the instructions carefully. Blood tests , which are always done in your provider's office or a lab. These tests can find very small amounts of hCG and show whether you're pregnant before you've missed your period. However, they aren't commonly used to check for pregnancy. That's because urine tests are less expensive, very accurate, and provide quicker results than blood tests, which may take hours to more than a day. Other names: human chorionic gonadotropin test, HCG test, qualitative hCG blood test, quantitative hCG blood test, Beta-hCG urine test, total chorionic gonadotropin, hCG total OB, chorionic gonadotropin
Why is this test ordered? You may need this test if you think you're pregnant. Symptoms of pregnancy vary, but the most common sign of early pregnancy is a missed period. Other common signs of early pregnancy may include: Swollen, tender breasts Fatigue Frequent need to urinate (pee) Nausea and vomiting (also called morning sickness) Feeling bloated or swollen in your abdomen (belly) or body You may also need a pregnancy test to make sure you are not pregnant if you need to have medical treatment that could harm a fetus. Lastly, you may need a quantitative blood test if you: Are at high risk for a miscarriage. The most common risk factors include active infections, thyroid disease , uncontrolled diabetes , obesity , and uterus or cervix problems. Have symptoms of an ectopic pregnancy. These can include abnormal vaginal bleeding, pain in your lower back and/or abdomen, and cramping on one side of the pelvis. Have symptoms of a molar pregnancy. These can include abnormal vaginal bleeding , pain in your abdominal or pelvic area, high blood pressure , and severe nausea.
Clinical Interpretation
Your results will show whether you're pregnant. A negative result means hCG wasn't found in your sample, so you may not be pregnant. However, this isn't always the case. If you did a home urine test too soon after getting pregnant, your body may not have made enough hCG to show up in the results. This is called a false-negative. A false negative result means your test shows that you aren't pregnant, but you really are. Because hCG levels increase every day during early pregnancy, it's a good idea to repeat the test a week after you took it the first time. If you get negative (not pregnant) results on two home tests, but you still think you're pregnant, call your provider. A positive result means that hCG was found in your sample. That usually means that you're pregnant. It's important to see your provider as soon as possible to make sure you get the right care . If you did a home test, your provider may do another test to confirm your pregnancy. In some cases, a home test may say that you're pregnant when you aren't. This is called a false-positive. A false-positive result means your test shows that you are pregnant, but you really aren't. Taking a pregnancy test while also taking fertility medicines could lead to a false-positive test result. If your results are positive but you think you might not be pregnant, talk to your provider. Learn more about laboratory tests, reference ranges, and understanding results .
Related ICD-10 Codes
Clinical Protocol & Patient Advice
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If you're doing a urine test, don't drink large amounts of fluid before collecting your sample. That could dilute the hCG in your urine, and it may not show up on the test. Taking medicine to help you get pregnant (fertility drugs) could affect your pregnancy test results. If you are taking fertility drugs , talk to your provider if you get a positive result. Your provider may need to verify it. Otherwise, you don't need any special preparations for a pregnancy test that uses a sample of your urine or blood.
Usage Guidance
- Reference ranges vary by laboratory. Always discuss your specific results with a qualified healthcare professional.
Source: MedlinePlus, National Library of Medicine. View the original.