For thousands of years women have attempted to “test for pregnancy” in a variety of ways. Ancient Greek and Egyptian writings record lengthy and complicated methods which were not scientifically based or accurate. It wasn’t until the 1940s that there was a way to conclusively determine a pregnancy before it became physically apparent.
Both blood and urine pregnancy tests work by detecting the presence of hCG, Human Chorionic Gonadotropin. This hormone is secreted by the developing placenta after implantation. The earliest that this hormone can be detected is four days before a period is expected, or about 6-10 days after conception.
hCG is measured in mIU’s. Blood pregnancy tests are the most sensitive and can detect hCG levels as low as 5 mIU’s. Additionally, a blood test will actually measure the amount of hCG present which can be valuable for determining how a pregnancy is progressing. hCG levels will double every 48 to 72 hours in healthy, viable pregnancy. This requires more than one blood test but it is the earliest and most accurate pregnancy test obtainable.
In the mid 1970s the home pregnancy test became available which allowed women the opportunity to easily and accurately find out if they were pregnant in the privacy of their homes.
Unlike a blood pregnancy test which measures hCG amounts, urine tests work by determining the presence of the hormone. The detection thresholds are between 20 mIU’s to 100 mIU’s, depending on the brand. Typically, the more expensive the over-the-counter test, the more sensitive and reliable it is.
Early detection of pregnancy can be helpful since an expectant mother who knows early on can avoid behaviors that might harm the pregnancy. However, a urine pregnancy test cannot tell you if the pregnancy will continue. One in six pregnancies will end in a miscarriage. Only ultrasound confirmation can determine whether or not a pregnancy is viable in the early stages of pregnancy.
CareNet offices provide free reliable tests. If you are concerned that you may be pregnant, please call us for an appointment.
The information provided here is general in nature. It is not a substitute for a consultation with a medical professional. Before any medical procedure, it is imperative that you discuss your personal medical history, risks, and concerns with your doctor. If you have questions during or after a procedure, your doctor should be immediately contacted. Avenue Women’s Center is not an emergency center. If you are experiencing severe symptoms, such as bleeding and/or pain, seek immediate medical attention. Contact your physician, go to an emergency room, or call 911.