Unlike LH tests, the OV-Watch monitors chloride in sweat when worn daily for a six-hour period (usually overnight). This method of testing offers its own conveniences and drawbacks, though it's not clear how effective it is. Reviewers say the OV-Watch can predict fertility about three days before LH tests, which is a plus.
Questionable accuracy, though recommended by some experts. A handful of experts recommend the OV-Watch Fertility Predictor, saying that chloride levels in sweat are a good means of predicting ovulation. As such, they say the watch can accurately predict ovulation several days in advance, unlike LH tests which only report two days of fertility. However, nearly all other studies' editors reviewed in this report say urine LH tests are the most reliable means of identifying ovulation. Reviewers, too, have mixed opinions. Some say the watch accurately identified ovulation, while others say it doesn't even monitor sweat and actually only works as a timer.
Time-saving, but possibly no easier than a digital LH test. Editors of JustMommies.com say the OV-Watch Fertility Predictor is easier to use than urine or saliva tests, as it gives a digital reading and doesn't require that you remember to take a urine test or saliva swab. While the digital reading is a nice feature, users still have to remember to wear the watch nightly, so it's no easier from that perspective. Some owners complain the watch can fall apart easily and that the instructions are a bit complicated. One pro: Users don't need to wait three to five minutes to see results; they need only glance at the watch each morning.
JustMommies.com editors review five fertility gadgets, including the OV-Watch Fertility Predictor. Editors say the watch is easier to use than other methods because it doesn't require a urine or saliva sample. Editors explain that the test determines fertility based on salt levels, which are said to fluctuate during a woman's cycle. They say the watch is more accurate than estrogen and LH tests because it can detect ovulation three days earlier.
Review: The Best Fertility Gadgets, Editors of JustMommies.com, Not Dated
Lennard, Lind and Honeywell say the OV-Watch works by detecting changes in chloride in a woman's sweat throughout her cycle. The authors cite studies that support this method of monitoring; they say the watch is just as effective as LH testing and that it can predict more fertile days than traditional LH tests.
Review: Advanced Technology for Fertility Prediction, Jaclyn Lennard , Jennifer Lind and Marlon Honeywell, Dec. 22, 2006
Amazon.com reviewers are generally unimpressed by the OV-Watch Fertility Predictor. Nearly 70 reviewers give it about 3.2 out of 5 stars. Some users contend the watch only counts days of the cycle and doesn't react to any chemical change at all. Others say it's difficult to set up or falls apart easily. Some, however, found the product helped them conceive. Overall, most owners don't find it to be any easier or more difficult than a urine test on a daily basis.
Review: OV-Watch Fertility Predictor Value Kit, Contributors to Amazon.com, As of July 2013