Home Ovulation Prediction Kits

QUESTION: My wife and I are trying to conceive our first child, and we're
wondering about the effectiveness of home ovulation prediction kits. What's
the purpose of these kits and how do they work? Do you think they are worth
the price? We appreciate your column and your good advice.
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ANSWER: The purpose of the ovulation prediction kits is to identify the peak
period of a woman's fertility during her menstrual cycle. Fertility
specialists identify this peak as occurring the day preceding and the day of
ovulation. Though the egg released by a woman's ovary can live only 12 to 24
hours, sperm can survive within the uterus for 48 to 72 hours. Couples who
try to conceive will therefore increase the odds of success by having
intercourse during this peak fertility time.
Because every woman's menstrual cycle varies, there was previously no
simple way to predict when ovulation would occur, with the exception of
measuring the ovulating woman's basal body temperature--or waking body
temperature--which tends to rise the morning following release of the
unfertilized egg, due to speeded-up production of progesterone during the
egg-production process. Obviously, becoming aware of the basal body
temperature's rise can only take place in hindsight, after the egg has been
released, which necessarily limits the time in which conception can be
pursued.
Home ovulation prediction kits differ in being able to predict the time
of ovulation through measurement of a chemical change which occurs prior to
release of the egg. A surge in the luteinizing hormone (LH), which starts 24
to 36 hours in advance of ovulation, usually in the early morning hours, is
unaffected by illness, amount of sleep, emotional factors or other things that
can disrupt basal body temperature. Ovulation prediction kits employ a
complex technical process to detect the change in LH through urinalysis.
At present there are at least three different kits on the market.
OvuSTICK, including nine tests in a one-month kit, is a 12-step process
requiring careful attention to instructions. Users collect urine to test
throughout the day; the surge can therefore be detected in its first stages.
The kit is easy to use: a stick immersed in the urine sample turns dark blue
color when the surge has taken place. OvuQuick is another kit that can
usually be found at most pharmacies.
A third brand, the First Response Ovulation Prediction Kit, is even less
expensive and less complicated, though it too requires some attention to
timing and details. Surging is monitored by adding color-changing chemicals
to a series of urine samples. In this test only the morning's urine is
collected, with the goal of identifying the surge's peak rather than its
onset. The kit thus predicts ovulation only 12-24 hours in advance.
Since a fertile couple has only a 10 to 20 percent chance of conceiving
in any given month and it takes average couples several months for the woman
to become pregnant, using any of these kits regularly should not be used as a
diagnostic tool for fertility problems or as a substitute for a fertility
workup. Rather they are an aid to proper timing, which in this case is
essential for success. The average cost of around $40 does not seem excessive
for these methods, which all have been proven to be effective when used as
directed.