Pregnancy Tests Used in Doctor Offices

Even though most women will take pregnancy tests in the privacy of their own homes, many will visit the doctor's office for confirmation of the result. Pregnancy tests used in doctor's offices include urine tests and blood tests. Though both tests are looking for the same hormone, the sensitivities of the test differ.

hCG Hormone

According to the American Pregnancy Association, both blood and urine pregnancy tests detect the presence of human chorionic gonadotropin or hCG. This is the hormone that is produced by the body when implantation occurs in the uterus. The level of this hormone doubles every two to three days during the first trimester of pregnancy and causes many of the early pregnancy symptoms that most women experience.

Urine Tests

Urine pregnancy tests are the most common and the least expensive pregnancy tests. The urine pregnancy test used in the doctor's office is very similar to the ones that are bought over-the-counter in most drugstores. The urine test detects the presence of hCG in the urine but does not detect the level of the hormone. This test is performed by either urinating directly on the test or by urinating into a cup and dipping the test strip into the sample. The results are available in a matter of minutes.

Blood Tests

Blood pregnancy tests are more expensive and must be conducted in the doctor's office. This type of test detects the level of the hCG hormone in the blood. With a healthy pregnancy, the hormone doubles every two to three days. When this does not occur, it can indicate an issue with the pregnancy. If the doctor suspects an issue or the patient has a history of complications, multiple blood tests may be ordered in the early weeks of pregnancy to monitor the levels of hCG in the blood. To conduct this test, the patient will have blood drawn and sent to the lab. The results from a blood pregnancy generally take a few days.

Timing

Urine pregnancy tests are most accurate if taken after a missed period. Though some tests may indicate a pregnancy before the period is missed, it is possible that hCG will not be built up in the system enough to indicate a positive. Blood tests can generally be taken early and give an accurate result. According to the American Pregnancy Association, a blood pregnancy test can be taken 7 to 12 days after conception.

Considerations

A false negative is more likely to occur than a false positive with a pregnancy test. If the woman's period does not start, the pregnancy test should be repeated. Because the blood test is more sensitive, the woman may choose to visit the doctor's office for a blood test if her period is late and the urine test is still showing a negative result.

References

• American Pregnancy Association