Please read ! Opks as pg tests !!

iVillage Member
Registered: 08-12-2003
Please read ! Opks as pg tests !!
3
Thu, 08-28-2003 - 10:54pm
I found this on another board thought this was real intersting !

I am a scientist and I thought I'd share what I know......

Chemically, LH and hCG are almost identical hormones. The difference is that hCG has an additional subunit called the beta chain. That's why you hear about quantitative hCG tests being called "betas"...because they are specifically testing for the beta subunit which is in hCG but not in LH. That's also why most pg tests will not turn + from LH. They react specifically to the beta subunit only. OPKs are a different matter. They are made to react to LH, which has the same chemical structure as hCG (the non-beta part). Therefore, if you are indeed pg you will get a +OPK. But it should be a true +OPK...like what you would see during your surge, not just 2 lines. If you are without a HPT but have some OPKs it will work if you are pg. I was afraid to take a HPT but I had a bunch of OPK s lying around so I tried one in the afternoon @ 12dpo. It was definitely + just like I had seen with my surge. I tested with a CBE and the line was faint but came up pretty quickly. I had a beta drawn the next morning and it came back at 93 (13 dpo).

If you get a TRUE +OPK in the 2ww, there are basically 3 possibilities:

1) you are pg and the OPK is detecting hCG.

2) you are not pg--somehow, you have misjudged your O time and what you are detecting is the LH surge just before O.

3) you are not pg--you have a disorder (i.e. PCOS) which causes fluctuating levels of LH throughout your cycle. In this case, again you are detecting a "surge" of LH.

I also wanted to add that while it is possible to get a +OPK in the 2ww and not be pg, I've never heard of someone actually being pg and NOT getting a +OPK (making the assumption that the test worked properly). Is there anyone out there who tested + with a HPT and not an OPK?

Personally, I find nothing wrong with using OPKs for HPT s as long as you understand why you could get a + and NOT be pg. The molecules are definitely closely related and there is overlap

iVillage Member
Registered: 08-12-2003
Thu, 08-28-2003 - 11:41pm
bump
iVillage Member
Registered: 08-10-2003
Fri, 08-29-2003 - 1:00am
I have been hearing so much about this lately I think I may try it next time. You can test a bit ealier with these right? As long as your pretty sure you ovulated...? There a bit cheaper, especially compared to the price of the early pregnancy tests, there the most expensive.
iVillage Member
Registered: 08-12-2003
Fri, 08-29-2003 - 6:56am
Im going to try it to ! I order from www.babywishes.homestead.com and there isent a whole lot of diffrence in prices of OPKs and pg tests. You can by 100 O strips for 34.50 and 100 pg strips for 30.00. I have both 100 o strips and 25 pg strips ( for 25 strips is 9.75)so im going to compare the results this cycle ! I think the O strips will show a +++ before the pg strips.