Lesson 12 - Fertility Monitors, OPKs, and Other Tests and Devices for Measuring Fertility

Lesson Objectives:

  • Understand how fertility tests and devices, such as fertility monitors and ovulation prediction kits can be used while fertility charting.
  • Learn how to use fertility tests and devices while charting and how to properly chart your results.

Major Points in this Lesson:

  • Using tests and devices to monitor your fertility is optional.
  • Commercial fertility devices work by detecting the presence of certain hormones in saliva or urine and analyzing their effects. 
  • Saliva microscopes, which respond to the presence of estrogen, show “ferning” when your estrogen (and fertility) are high.
  • Ovulation prediction kits, which respond to the luteinizing hormone (LH), emit a “positive” when you are most fertile, just before ovulation.
  • Fertility monitors and advanced forms of OPKs respond to both estrogen and luteinizing hormone. When estrogen levels are high, these devices indicate “high” fertility and when they detect a surge of LH, the devices indicate a “peak”.
  • While these tests and devices are not essential to create a reliable and accurate chart, they can be used to cross-check your fertility signs.

Today there are numerous commercial products on the market designed to indicate changes in fertility throughout the month. These tests and devices detect specific hormones in your saliva or urine. When using these types of products, it’s important to follow all manufacturer instructions. If you have any additional questions, call the toll-free number provided by most manufacturers. 

Information derived from these devices and kits provide additional information about your fertility status. While optional, you can take the results of these devices and kits to complement observations from your primary fertility signs. Concise readings from your BBT and cervical fluid, coupled with consistent charting, can help you better monitor your fertility.

While fertility kits and devices can be useful when cross checking your fertility signs, charting your BBT is your best option for pinpointing ovulation. After ovulation, your body experiences a thermal shift due to an increase in progesterone. By monitoring your BBT using an in-ear thermometer, you can time intercourse for better odds of conception.

Fertility Monitors and OPKs

Ovulation Prediction Kits, otherwise known as OPKs, are a type of Ovulation Prediction Test (OPT) used to help women determine their fertile time. OPKs work by detecting the presence of Luteinizing Hormone (LH) in urine, which surges approximately 24 hours prior to ovulation. LH causes the ovaries to produce enzymes which cause a follicle to rupture and release an ovum into a fallopian tube. This process is known as ovulation. If you use an OPK the day before you ovulate, the result should be positive. You may also get a positive result the day of ovulation. 

Follow these guidelines for the proper use of OPKs:

  • Read and follow the manufacturer’s instructions.
  • Test daily before you expect to be fertile to avoid missing the surge. Your first positive OPK will likely indicate that you are about to ovulate. As test strips can be costly, time your tests carefully.
  • Check the manufacturer’s instructions to determine the best time of day to use your OPK. Your first morning’s urine may not be the best test source as your LH surge often begins while you’re still asleep. Late morning or early afternoon urine is often best unless the manufacturer’s instructions suggest otherwise.
  • If the test line on your OPK is as dark as or darker than the control line, record your results as positive. If the test line is lighter than the control line, record your results as negative. Follow the manufacturer’s instructions for digital OPK tests.
  • As the results from OPKs are not always accurate, do not time your intercourse according to test results. It’s possible not to see a positive OPK even though you are fertile. As sperm can survive in the reproductive tract in cervical fluid for several days, increased fertility begins before you see positive test results.
  • During your fertile time and before you see a positive OPK result; engage in intercourse a minimum of every other day. Once you have a positive test result, engage in intercourse daily.
  • Consult with your doctor or the manufacturer of the OPK if you are taking Clomid.

How to Record Data from Fertility Devices and Kits

  • When using salvia microscopes, record as No ferning / Partial ferning / Full ferning
  • When using ovulation prediction kits, record as Positive / Negative 
  • When using fertility monitors or OPKs, record as Low / High / Peak

While fertility devices and kits are useful in determining your level of fertility, they do not substitute for BBT charting. With a quality in-ear thermometer, monitor your basal body temperature to best determine fertility.