Blood vs Urine test?

iVillage Member
Registered: 03-07-2002
Blood vs Urine test?
2
Tue, 09-09-2003 - 3:55pm
How soon can you find out that you are PG by taking a blood test? What is test called? And how hard is it to get a doctor to order it? How long does it take to get results if they don't "send them out to a lab"?

Are doctor's urine tests more sensitive than HPTs?

Thanks

Kimber

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iVillage Member
Registered: 06-30-2003
Tue, 09-09-2003 - 4:08pm
GA Kimber- hope I don't set anyone off with my response..... PG blood tests can be accurate fairly quickly right after implantation, so I'd say even possibly as early as 5 to 7 dpo. You want a quantitative HCG test (serum pregnancy test)- which measures the amount of hcg in your blood- anything over 7 is considered pregnant and most dr's will have you come in for a follow b/t again in a day or two to recheck the number to make sure it is doubling like it should, especially if you're around the 7ish mark and not much higher. From my experience- dr's aren't thrilled with ordering serum b/t to check for pregnancy. My ex-ob/gyn swore that the hpt's he had were more accurate than b/t, but my now midwife disagrees and that he may have caused me to m/c by giving me too much progesterone while telling me I was anovulatory when he should have ordered a b/t to confirm I was or was not pg first (I test very late- 25 dpo with urine tests).... so unless you've been pg and/or m/c before now- I doubt your dr will be wanting to rush into a b/t for you. The whole b/t takes minutes - I want to say like 20 or 30 to perform, labs will usually have them done within four hours or so, so usually dr's will have the results back by the next "business" day. Are dr's tests more sensitive than over-the-counter hpt's? No, depending upon which hpt you buy- these new First Response Early tests are great for detecting low levels of hcg.

GL! Hope my two cents doesn't offend anyone. ((((((((hugs)))))))))) Connie

iVillage Member
Registered: 04-21-2003
Tue, 09-09-2003 - 4:15pm
There are two types of blood tests. One is qualitive, where the lab has a set HcG level to tell you if it is positive. For example if the lab only gives positive on 25 mIU/ml and you only have 20 mIU/ml of HcG then it will come back negative even though you are pregnant. The other is a quantitive test that actually tells you how many mIU/ml of Hcg you have in your blood, this test would come up with a number instead of just a negative or positive. They say HcG can be detected in the blood anywhere from 7-10 dpo so you could have it done as early as a week before AF is due.

As far as the doctors urine tests go I am not sure if every doctor uses the same kind of test but I have heard of alot of women who were indeed pregnant got a positive on an early hpt at home and then got a negative at the doc's office. I am pretty sure their tests measure something like 50-100 mIU/ml of hcg and the early home tests such as FRE (first response early) can detect hcg as low as 15 mIU/ml. Another factor to take into consideration is when you take an hpt it is better to use first morning urine because it will have the most concentration of hcg in it, when you go to the doctors office you are probably not using fmu so you won't have as much hcg in your urine as you would if you had tested at home in the morning.

Good Luck and I hope this helps.

Tasha


Edited 9/9/2003 4:16:05 PM ET by circumstance