We’ve probably all seen or heard the jokes about pregnancy tests where the doctor lets a woman know she’s pregnant by saying “the rabbit died.”
The Rabbit Test came into vogue in 1927 when it was discovered that if urine from a pregnant woman was injected into a female rabbit, the rabbit’s ovaries would show distinct changes.
Saying “the rabbit died” as a catch phrase to indicate pregnancy was misleading, because actually all of the rabbits died as they had to be killed in order to look at their ovaries.
The Rabbit Test is now defunct, thank goodness, and there are modern pregnancy tests that don’t require the sacrifice of poor rabbits.
There are two types of pregnancy tests today. One uses urine, the other a blood sample. Both tests detect the presence of Human Chorionic Gonadatropin, or hCG.
hCG is a hormone that is produced by the placenta soon after the embryo attaches to the lining of the uterus. hCG will build up very rapidly in a woman during the first few days of pregnancy.
Urine Tests
Urine tests to determine pregnancy may be performed at home, or at the doctor’s office, depending on the type of test. Urine tests will vary as to how long it takes to get a result.
You might be looking for a certain change of color, a line, or a symbol.
How Accurate are Urine Tests for Pregnancy?
If done correctly, urine tests for pregnancy—including home pregnancy tests—are usually about 97% accurate. It is best to wait at least until the first day of a missed period.
If you get a negative result from a home pregnancy test, wait another week or so, then retest.
Blood Tests
There are two types of blood tests for pregnancy:
- Quantitative test
- Qualitative test
The qualitative blood test simply gives a yes or no answer. “Yes,” you are pregnant, or “No” you are not pregnant.
The quantitative blood test measures the exact amount of hCG in your blood.
There are advantages and disadvantages to having a blood test done to detect pregnancy.
Advantages:
- A blood test is able to detect pregnancy earlier than a urine test, usually at around the 7th-12th day of conception.
- A blood test can measure the amount of hCG in your blood
Disadvantages:
- Costs more than a urine test
- Takes longer to get a result
- Must be performed in a doctor’s office
Most pregnant women will end up having both types of pregnancy tests.
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