How Accurate Are Blood Tests To Determine Pregnancy?


Share |

The most important thing to consider when thinking about how any test, whether it is a blood test to determine pregnancy or whether it is an at-home urine test to determine pregnancy, is that a pregnancy test really only is looking for one thing. A pregnancy test is looking for only the presence of Human Chorionic Gonadotropin, or hCG for short. Some blood tests will check the actual level of hCG that is present in a woman’s system, where other blood tests and most urine tests used to determine pregnancy only check for the presence of a specific amount of hCG, and give a “yes” or “no” type answer, rather than an answer of the numerical level of hCG in a woman’s body. The one test is considered “quantitative” in that it gives the quantity of hCG in the woman’s blood. The other sort of test is considered “qualitative” in that it qualifies whether hCG is there or not.

It is important also to think about how exactly conception occurs, and when hCG can be found in blood. A woman’s body does not start producing hCG until after the fertilized egg has implanted in the wall of the uterus. This typically will occur between 7 and 10 days after the woman ovulates. Within a couple of days, there should be enough hCG in the woman’s body that the most sensitive of the tests used to determine pregnancy should be able to pick it up, whereas other tests, including some blood tests to determine pregnancy, may not yet be able to accurately tell whether the woman is pregnant or not. On the average, blood tests to determine pregnancy are not typically as sensitive as urine tests, but are at least as accurate.

By the time that a woman has missed her period, however, nearly all tests to determine pregnancy, including blood tests to determine pregnancy, become around 99% accurate. At that point there is enough hCG in the woman’s system that even the least sensitive tests will be able to pick up on its presence.



Share |



This entry was posted in Getting Pregnant.



 



Article Categories

Copyright 2007-2014 DownTheLane.com. All Rights Reserved. Return Policy | Shipping Info | Site Map