Femme la Phoenix
12-05-2006, 15:58
One thing that many of you have asked recently is, "what is the best opk?", "what is the most senistive opk and do they truly work?"
I was surprised with the results and was busting to share it with everyone. I hope this helps demisterfy which tests work best, when to test and which one!!
Regarding OPK Sensitivity: OPK's are not like HPT's. Most women want HPT's that detect as little hCG as possible, because hCG is only produced during pregnancy*. Therefore, the more sensitive the HPT, the earlier it can detect pregnancy.
OPK's measure LH, which a hormone that is always present in the female body in some quantity. This hormone surges 12-48 hours before ovulation. In women of normal fertility, a "surge" (indicating ovulation is near) means at least 20 mIU/mL of LH is present. The vast majority of women experience a surge of 40 or more mIU/mL. Since a surge builds very quickly, a woman may go from an insignificant amount of LH to 40 mIU literally within an hour or so.
Therefore, an OPK that measures 20-40 mIU is adequate, and a more sensitive OPK (20 mIU) does not offer any real benefit over a less sensitive one (40 mIU.) It's possible that a woman may experience a "slower" surge, and "linger" at 20 before shooting up to 40 the next day. (This may differ from cycle to cycle for the same woman. It has no physiological significance.)
I noticed that when I use a more sensitive OPK (20 mIU) I can detect ovulation approximately 36-48 hours before the fact; using a less sensitive one (30-40 mIU) I have only 24 hours' notice. If you happen to use 2 brands within the same cycle, this difference in sensitivity can prove confusing.
When to test?
21 days Day 5
22 days Day 6
23 days Day 7
24 days Day 8
25 days Day 9
26 days Day 10
27 days Day 11
28 days Day 12
29 days Day 13
30 days Day 14
31 days Day 15
32 days Day 16
33 days Day 17
34 days Day 18
35 days Day 19
36 days Day 20
37 days Day 21
38 days Day 22
39 days Day 23
ok but what is the best test??
One test I found out preformed all others.....
Still another problem confronts the 38 percent of women whose surge lasts less than 10 hours. If they test just once a day, as the kits instruct, they could easily miss the surge completely.
But research shows that following that advice may cause a significant minority of women to miss their LH surge completely. In a detailed study of 221 healthy women, Allen J. Wilcox, M.D., Ph.D., and his colleagues at the National Institute of Environmental Health Sciences, a federal research laboratory in Durham, N.C., found considerable variability in ovulation dates. For instance, among women with a 28-day cycle (the most common), ovulation occurred as early as day 10 and as late as day 22. If a woman who ovulated on day 10 were to follow the advice of the package insert and start testing on day 11, she would already have had her LH surge for that cycle. And, no matter how sensitive, the tests will not be able to predict ovulation for the 9 percent of women whose LH surge, for some reason, occurs after ovulation.
11 top-selling ovulation kits found one clear winner, the ClearPlan Easy Ovulation Test Pack, that's sensitive enough to predict ovulation for nearly 9 out of 10 women, and also exceptionally easy to read.
At their peak, most women's LH surges range from less than 20 to 100 mIU/ml (thousandths of an International Unit per milliliter).
I was surprised with the results and was busting to share it with everyone. I hope this helps demisterfy which tests work best, when to test and which one!!
Regarding OPK Sensitivity: OPK's are not like HPT's. Most women want HPT's that detect as little hCG as possible, because hCG is only produced during pregnancy*. Therefore, the more sensitive the HPT, the earlier it can detect pregnancy.
OPK's measure LH, which a hormone that is always present in the female body in some quantity. This hormone surges 12-48 hours before ovulation. In women of normal fertility, a "surge" (indicating ovulation is near) means at least 20 mIU/mL of LH is present. The vast majority of women experience a surge of 40 or more mIU/mL. Since a surge builds very quickly, a woman may go from an insignificant amount of LH to 40 mIU literally within an hour or so.
Therefore, an OPK that measures 20-40 mIU is adequate, and a more sensitive OPK (20 mIU) does not offer any real benefit over a less sensitive one (40 mIU.) It's possible that a woman may experience a "slower" surge, and "linger" at 20 before shooting up to 40 the next day. (This may differ from cycle to cycle for the same woman. It has no physiological significance.)
I noticed that when I use a more sensitive OPK (20 mIU) I can detect ovulation approximately 36-48 hours before the fact; using a less sensitive one (30-40 mIU) I have only 24 hours' notice. If you happen to use 2 brands within the same cycle, this difference in sensitivity can prove confusing.
When to test?
21 days Day 5
22 days Day 6
23 days Day 7
24 days Day 8
25 days Day 9
26 days Day 10
27 days Day 11
28 days Day 12
29 days Day 13
30 days Day 14
31 days Day 15
32 days Day 16
33 days Day 17
34 days Day 18
35 days Day 19
36 days Day 20
37 days Day 21
38 days Day 22
39 days Day 23
ok but what is the best test??
One test I found out preformed all others.....
Still another problem confronts the 38 percent of women whose surge lasts less than 10 hours. If they test just once a day, as the kits instruct, they could easily miss the surge completely.
But research shows that following that advice may cause a significant minority of women to miss their LH surge completely. In a detailed study of 221 healthy women, Allen J. Wilcox, M.D., Ph.D., and his colleagues at the National Institute of Environmental Health Sciences, a federal research laboratory in Durham, N.C., found considerable variability in ovulation dates. For instance, among women with a 28-day cycle (the most common), ovulation occurred as early as day 10 and as late as day 22. If a woman who ovulated on day 10 were to follow the advice of the package insert and start testing on day 11, she would already have had her LH surge for that cycle. And, no matter how sensitive, the tests will not be able to predict ovulation for the 9 percent of women whose LH surge, for some reason, occurs after ovulation.
11 top-selling ovulation kits found one clear winner, the ClearPlan Easy Ovulation Test Pack, that's sensitive enough to predict ovulation for nearly 9 out of 10 women, and also exceptionally easy to read.
At their peak, most women's LH surges range from less than 20 to 100 mIU/ml (thousandths of an International Unit per milliliter).