Pregnancy Test - Sensitivity Comparison

Pregnancy Tests and hCG Values

The pregnancy tests on the market today range widely in their sensitivity in picking up the pregnancy hormone, hCG. In the chart below, the lower the number in the "hCG Detected" column, the earlier you can use the pregnancy tests. As a general rule, hCG levels, if you are pregnant, are between 5 - 50 mIU a week before your period is due. The hCG levels in your system should double every two to three days.

Please remember that every woman is different and the time it takes for the fertilized egg to implant in your uterus wall can vary. A common misconception is that implantion occurs 7 days after conception, but the research findings showed that first appearance of HCG (implantation) occurred 6-12 days after ovulation, with 84% of the pregnancies implanting on days 8-10 after ovulation. If you don't get a positive pregnancy test, it doesn't necessarily mean that you are not pregnant. It could be that you ovulated later than you thought (meaning that conception and subsequent hCG production didn't happen as when you expected) or that, for you, implantation took longer than the average. Your period arriving is a sign that you are not pregnant this cycle, as is a negative blood test from your doctor.

Is a super sensitive pregnancy test the best to use?

For most women, the resounding answer would be YES! It allows you to know earlier if your attempts to conceive were sucessful and get medical care as soon as possible. There *is* a down side to extra sensitive pregnancy tests though. 25% of all pregnancies unfortunately end in miscarriage and many of these being very early pregnancies. If you use a very sensitive pregnancy test, where you test before the day your period is due, you could catch an early pregnancy but end up going on to have your period anyway due to a very early miscarriage. Some women will find it very hard to deal with this sort of emotional rollercoaster.

Pregnancy Test Sensitivity Chart

Sensitivities checked with manufacturers in July 2007

Test Name Lowest hCG detected AimStrip (aka AimStick) Pregnancy Test Strip 20 mIU   Buy Here! AccuHome Midstream Pregnancy Test 25 mIU   Buy Here! Accuclear Pregnancy Test 25 mIU Answer Early Result Pregnancy Test 25 mIU Clearblue Easy +/- 25 mIU Clearblue Easy Digital (1 piece, blue cap) 25 mIU Clear Choice w/ Cup 25 mIU Confirm 1-Step Pregnancy Test 25 mIU CVS Early Result Pregnancy Test 25 mIU Dollar Store Brand (mini-strip, cassette, & midstream) 25 mIU Early Detect 25 mIU e.p.t. +/- Test 25 mIU e.p.t. 1-Step Digital Test 25 mIU e.p.t. Certainty Digital Test 25 mIU Equate +/- (Wal-mart) 25 mIU Equate Pregnancy Test (Wal-mart) 25 mIU Fact Plus Midstream Pregnancy Test 25 mIU First Response Early Result Pregnancy Test 25 mIU One Step Be Sure Pregnancy Test 25 mIU Right Aid Pregnancy Test 25 mIU Target Brand Pregnancy Test 25 mIU Walgreen Midstream Pregnancy Test 25 mIU Walgreen Digital 25 mIU Fact Plus Cassette 40 mIU Clearblue Digital 50 mIU CVS "Early Result" Cassette Pregnancy Test 50 mIU Drug Emporium Brand Pregnancy Test 50 mIU early Pregnancy test 50 mIU Walgreens Cassette Pregnancy Test 50 mIU