The development of new biological and electronic technology now provides women with the ability to self-monitor female hormones. These fertility monitors provide an objective picture of fertility.
The most readily available fertility monitoring technologies are the urinary LH test kits (sometimes called ovulation test kits) and the Clearblue Fertility Monitor that measures urinary LH and estrogen. Both the Clearblue monitor and the LH test kits are designed to help couples achieve pregnancy. However, when used appropriately and with the proper instructions they can also be used as an aid to avoiding pregnancy.
The Clearblue Fertility Monitor (formally called the ClearPlan Easy Fertility Monitor) is a small hand held battery (4 AAA batteries) operated device (See Figure 4). The monitor has a small window or screen that provides information on the day of the cycle and the level of fertility. It also has a slot where the fertility test sticks are read for the levels of estrogen and LH. The Clearblue test sticks are in white plastic covering. On the end of the test sticks there is a paper strip that contains the assay materials that detect urinary estrogen and LH.
Fig. 4. Clearblue fertility monitor
The monitor has a small screen on the right hand side
(see Figure 4). The screen will indicate the day of the cycle, the level of fertility, and when a test is required. On the right side of the screen is a small button with an "M" on it. The woman user pushes this button on the morning of the first day of her cycle, i.e., the first day of menses (the first day of her period). Each morning when waking, she is instructed to push a button on the side of the monitor that will record a new day of the cycle. The Clearblue monitor will then provide the user with information on the day of the cycle. In Figure 4 you can see that it is day 15 of the cycle.
At about day 6 of the cycle, the monitor will flash a test strip icon to indicate that a test should be done. The woman user takes a test strip and places it under her urine stream for 3 seconds. The first urination in the morning should be utilized. She then places the test strip in the slot on the monitor until it indicates that it has been read. This will take about 30 seconds. The monitor usually will ask for 10 test strips to be read over a 10-day period. Occasionally, the monitor will require 20 readings. The woman has a 6-hour window in which to perform the test. The 6-hour window is triggered when the user pushes the "M" button to indicate the beginning of her cycle. For example, if the woman user pushes the M button at 6 AM, she will then have from 3 AM to 9 AM to perform the test.
The monitor will provide the user with 3 levels of fertility (Low, High, and Peak Fertility). Low fertility indicates that there is a low probability of achieving a pregnancy on that day. Low fertility is shown by one dark block on the monitor window. High fertility indicates that there is a high probability of achieving pregnancy on that day. The high fertility day is triggered when the monitor picks up a threshold level of urinary estrogen. Two dark blocks on the monitor’s window indicate high fertility. Three dark blocks with the top block showing an icon of a ripe follicle indicates Peak fertility. Peak fertility also means that the LH surge is taking place. The monitor will provide the user with 2 days of Peak fertility. The user will know that after the second day of peak fertility there is a good probability that she will be ovulating the next day. After the 2 days of Peak fertility, the monitor automatically will provide one day of High fertility.
The advantages of the ClearBlue monitor are that it provides fast accurate, objective, and very clear information about fertility, i.e., low, high, and peak fertility. It has two of the best urinary assays to predict ovulation - urinary estrogen and LH. On average the monitor will provide a 2-5 day warning before the actual day of ovulation. It is simple to use and understand.
The disadvantage of the monitor, if using it to avoid pregnancy, is that the 2-5 day warning period it provides is not long enough to avoid pregnancy, and it does not tell anything about the status of cervical mucus. Furthermore, the monitor itself costs about $175, and the test strips cost about $18–20 dollars per month.