Pregnancy tests help women to determine if they are pregnant. These tests work by picking up on markers in urine or blood that indicate pregnancy. Knowing which type of pregnancy test is most suitable, and understanding how to use them, helps ensure results are accurate. Whether taken at home or in a doctor's office, being informed about the pregnancy test process makes it easier to understand what the results mean, and what to do next.
Types of pregnancy test
There are two main types of pregnancy test available: urine tests and blood tests.
Urine tests can be taken at home or at the doctor's office. They detect the presence of the pregnancy hormone, human chorionic gonadotropin (hCG).
The hCG hormone circulates in a woman's blood once a fertilized egg has attached to the uterus wall. This usually happens six days after fertilization.
According to the American Pregnancy Association, levels of hCG double every 2 to 3 days, peak by 8 to 11 weeks of pregnancy, and then begin to level off. HCG can usually be detected by a urine test 12 to 14 days after conception.
Home pregnancy test
Home pregnancy tests can be purchased in a pharmacy or drugstore. They normally cost less than $20 and are easy to use. If used correctly, they give excellent results.
Results are usually visible within 3 to 10 minutes or sometimes sooner.
Several different brands and types of pregnancy tests are available. Most can be classed as standard tests or digital tests:
Clinical urine tests are performed at a doctor's office. Like home tests, they also look for the presence of the hCG hormone in urine.
Although they produce the same level of accuracy, tests performed n a clinical setting usually avoid some of the errors that can happen with home tests.
Waiting times for clinical results vary. Some facilities can provide results immediately, while others may take up to a week.
Although less common than urine tests, blood tests to detect hCG levels are available. These are always carried out at the doctor's office, and results take longer than urine test results.
Blood tests are usually more expensive but some can be taken earlier than urine tests to determine results. The two types of blood tests are:
This process can help indicate ectopic pregnancy, miscarriage, or a more accurate due date.
Several websites and phone applications have tests that claim to calculate the likelihood of being pregnant. These can be used as a source of information, but should not replace real pregnancy tests.
Who should use a pregnancy test?
Any woman of childbearing age, who suspects she may be pregnant, should use a pregnancy test. In particular, women who recently had unprotected sex should consider using a pregnancy test.
Some signs of early pregnancy that should be followed up with a pregnancy test include:
For a clinical urine test, the doctor will ask for a sample of urine. This can be tested immediately, or sent to a laboratory for testing at a later stage.
Blood tests require a sample of blood to be drawn and sent for testing.
Home pregnancy tests are simple to use. It is important to follow the instructions closely to get the most accurate result.
Most brands can be used on the first day of a missed period, but some more sensitive tests can be used sooner. Some clinical tests can also be taken earlier than this.
In general, home pregnancy urine tests involve one of the following methods:
Many home pregnancy tests claim to be accurate up to 99 percent of the time. Clinical tests can be even more accurate.
However, using them correctly is vital. Several studies suggest incorrect use of tests has led to many women reporting false results.
Most tests can be used on the first day of a missed period but it's advisable to wait 1 week after a missed period for accuracy.
This is because 10 to 20 percent of pregnant women won't detect their pregnancy on the first day of their missed period. This can be due to many women having irregular periods, or miscalculating when their period is due.
In addition, a number of other factors play a role in the accuracy of results, including:
Results of a pregnancy test are either positive or negative. If taking a clinical test, the doctor will explain what the results mean. If using a home test, it's important that women refer to the test instructions to ensure they understand what the colors, symbols, or words indicate.
A positive result indicates pregnancy, even if the color, symbol, or words on the test window are faint. It's a good idea to confirm this result by taking a clinical test.
Very rarely, a false-positive result occurs. This means the woman taking the test is not pregnant, despite the test indicating she is. False-positives can occur due to:
A negative result means pregnancy is unlikely. However, false-negative results are common.
These are where pregnancy may still occur but is not yet showing up on the test. They can occur for a number of reasons, including:
When to see a doctor
A woman should always consult her doctor if she has any queries about the pregnancy or test results. If the home pregnancy test is positive, a doctor can confirm this with a clinical test and begin to arrange prenatal care.
If a home pregnancy test is negative but a woman's periods don't resume, she should consult a doctor to determine the cause of the missed periods.
The original article was published on medicalnewstoday.com