How do pregnancy tests work?
If you’ve ever taken a home pregnancy test, you probably felt many different emotions at the same time. What do those little lines really mean? Simply understanding how pregnancy tests work, may reduce some stress. This article will answer your questions about how pregnancy tests work. You will also learn how an ultrasound offers important information about your pregnancy.
Pregnancy tests work by measuring the amount of Human Chorionic Gonadotropin or hCG in the body. HCG is often called the “pregnancy hormone.”
What is hCG?
HCG is often called the “pregnancy hormone” because the placenta produces HCG which can be detected in the blood and urine when someone is pregnant.
After an egg is fertilized by sperm, it travels through the fallopian tubes to the uterus. The fertilized egg – also known as an embryo – attaches to the wall of the uterus. This is called implantation and it triggers the placenta to form. The placenta produces and releases hCG – the pregnancy hormone – into the blood and urine.
How soon can HCG be detected?
HCG can be detected in urine from 7-9 days after fertilization as the embryo attaches and implants in the uterus. As the pregnancy grows, the hCG levels increase.
There are two types of pregnancy tests:
- 1.Urine pregnancy test
- 2.Blood pregnancy test
A urine pregnancy test detects hCG in the urine. This type of pregnancy test can detect levels of hCG in urine at about 12 to 14 days after conception- when your period is due.
A blood pregnancy test detects hCG levels in the blood. This type of pregnancy test can detect hCG in blood approximately 11 days after conception – right before your period is due.
What’s the difference between urine and Blood pregnancy tests?
There is a difference between urine and blood pregnancy tests.
A urine test shows a positive or negative result, while a blood test measures the amount of hCG in the blood. Repeated blood pregnancy tests check increasing levels of hCG during early pregnancy. However, blood tests do not replace the importance of an early pregnancy ultrasound. An ultrasound determines how far along the pregnancy is, that it’s growing in the right place, and whether it has a heartbeat.
Why is an ultrasound important?
An ultrasound is important because it gives you much more information than a urine or blood pregnancy test. An ultrasound tells 3 important things:
- A small percentage of pregnancies implant and begin growing outside the uterus which can become life-threatening to the pregnant person if undetected and/or untreated. An ultrasound confirms that the pregnancy is growing in the right place in the body.
- About 30% of early pregnancies end naturally during the first trimester. An ultrasound will confirm whether there is a heartbeat and that the pregnancy is viable. For someone considering abortion, an ultrasound is very important before taking pills or undergoing a procedure that might not be necessary.
- Pregnancy tests are not able to tell you the exact age of a pregnancy. An ultrasound measures the exact gestational age of the pregnancy – how many weeks along it is. For someone considering abortion, it’s very important to know the exact age of the pregnancy since that will determine which methods or procedures are available to them.
Jewel Women’s Center offers free pregnancy testing and free ultrasound. Contact us today to schedule an appointment and get the important information you need.