Ovulation Tests

[Jennicadd]

I'm not sure if I'm allowed to copy and paste this or not, but it is from consumerreports.org and I'm not trying to break any copyright laws-

The fertility window
One ovulation-test kit outperformed the pack, while one performed poorly.



HIGH-TECH AND LOW The reusable electronic ClearPlan Easy Fertility Monitor, above, is fairly sensitive but, at $195, pricey. The $22 cassette-type Inverness Medical Early Ovulation Predictor, right, is low-tech. It calls for the use of nothing more than a cup and a medicine dropper.


When an ovulation-test kit works right it reliably identifies the most fertile 24 to 48 hours in a woman's cycle, the time in which the great majority of successful pregnancies are conceived. Our tests of 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. We also found one markedly insensitive product, the Answer Quick & Simple One-Step Ovulation Test, that may not function for many users.


HOW THE TESTS WORK

The day of ovulation, when a ripened egg bursts out of its follicle, and the five days preceding it, are the fertile window of the female reproductive cycle. The actual day of ovulation and the day preceding it are the most fertile days, and more than 80 percent of viable pregnancies are conceived on those two days. It is rare for a woman to get pregnant a day or more after ovulation has occurred.

There's a hormonal harbinger of ovulation called luteinizing hormone (LH) that peaks in blood and urine one to two days before ovulation, at the onset of the most fertile period in the cycle. The length of the LH surge is highly variable, lasting between 10 and 31 hours in about half of women, less than 10 hours in 38 percent of women, and more than 31 hours in 12 percent. LH surge-peak values also vary widely. But research over the years has firmly established that the LH surge is among the most reliable predictors of ovulation, which is why ovulation test kits measure that hormone.

Ten of the 11 kits we tested also look and work like home pregnancy tests, using monoclonal antibody sensing technology. They cost from $12.59 to $32.76 for a package of 5 to 7 tests. The user either urinates on an absorbent wick, dips a test stick into a cup of urine, or places a few drops of urine on a cassette. The result appears as a line in a tiny window, which must be at least as dark as, or darker than, the line in the test-validation window. Since ovulation detection will almost certainly require multiple tests, the kits include five or more individual test sticks.

By contrast, the highly rated ClearPlan Easy Fertility Monitor, which also uses monoclonal antibody sensing technology, is a reusable palm-size device. It electronically senses not only the LH surge, but the less intense surge of another hormone, estradiol, which precedes the LH surge by about a day. It can also store cycle-length information from up to six previous cycles. Users urinate on a disposable stick, then insert the stick into the machine's slot. The estradiol and LH surges appear as rectangles on the device's LCD window.

The product retails for about $195, including a starter kit of 20 test sticks. Replacement packs of 30 sticks sell for about $50.


A QUESTION OF TIMING

Since ovulation occurs partway through the menstrual cycle, the first challenge women face is figuring out when to use the kits. The package instructions advise that to use the test most effectively, women should know the length of their usual menstrual cycle. Using tables on the package inserts, they should start testing a specified number of days after the onset of their last period. For example, the top-rated ClearPlan Easy Ovulation Test Pack advises women with a 28-day cycle to test from day 11 to day 17; a woman with a 32-day cycle should start on day 14 and continue to day 20.

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.

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.


HOW THE TESTS PERFORMED
OUR TOP-RATED PRODUCT The ClearPlan Easy test kit will detect ovulation for about 9 out of 10 women.


Working with an independent laboratory, we conducted tests using female urine spiked with various concentrations of LH. Following package instructions, we tested each model with increasing LH concentrations up to the point where we obtained a positive reading. We read the results after the waiting time specified on each product's package insert (typically 1 to 3 minutes), and again after 10 minutes, the maximum allowable reading time.

Though most of the kits are labeled as having "99 percent clinical accuracy," in actual use even the best-performing products are likely to detect LH surges in a considerably lower percentage of women. At their peak, most women's LH surges range from less than 20 to 100 mIU/ml (thousandths of an International Unit per milliliter).

The top-rated product, the ClearPlan Easy Ovulation Test Pack, was the only one able to detect LH concentrations as low as 22 mIU/ml. It was also easier to read than most other models. But even this product will not detect ovulation in the 12 percent of women whose LH peaks at below that concentration.

Its costly sister product, the ClearPlan Easy Fertility Monitor, was the second most sensitive model we tested. It detected LH concentrations as low as 36 mIU/ml, meaning it may work for about 65 percent of women.

At the other end of the spectrum, we had to spike the test urine with the highest LH concentration we tested--91 mIU/ml--before we obtained a positive reading from the First Response Pregnancy Planning Kit. Only 20 percent to 25 percent of women have an LH peak that high. Those results cast doubt on the product's label, which claims it contains enough test sticks "for 90 percent of ovulating women to detect hormone surge."

The worst-performing test kit, the Answer Quick & Simple One-Step Ovulation Test, didn't do even that well. In laboratory tests using urine with an LH concentration of 91 mIU/ml, only one of six tested Answer kits registered positive. When we tested another six samples at a concentration of 96 mIU/ml, we got only two positive readings.

[eaglet]

Thanks for posting this!

while I use lots of different brands of hpts, I only use one brand of OPK - the Clearplan. My old RE's office only recommended that brand; looks like things haven't changed much in the last few years as far as quality goes with the other brands. The clearplan OPKs have been working very nicely for me on metformin.