Ovulation Prediction Kits
Ovulation prediction kits (OPKs) measure urinary luteinizing hormone (LH) levels to predict the timing of ovulation. This involves checking the urine daily for the presence of LH with an OPK. These kits use paper dipsticks or cassettes that can detect changes in LH levels in the urine. LH is usually produced in small amounts during the menstrual cycle but suddenly increases for a short time before ovulation. This increase is termed the “LH surge” and usually causes ovulation to occur within 36-40 hours. Timing of intercourse and inseminations are more effective with the use of OPKs.
Which kit is recommended?
You can start with any kit purchased at the drug store. There are two common types of kits: ones that display a line on the test strip to be compared with a reference line, and ones that are digital and flash a 😄 or YES in the test window.
- The brands we recommend include:
- Clearblue Digital Ovulation Test
- First Response Daily Digital Ovulation Test
We advise that you DO NOT purchase advanced fertility monitors, such as Clearblue Fertility Monitor or Clearblue Advanced Digital Ovulation Test. These kits measure rising estrogen levels, which can be affected by fertility medications. These are the kits that advertise both “high” and “peak” readings.
Guidelines for use
- Begin OPKs on cycle day # 10.
- Follow the manufacturer’s instructions for performing the test. Timing is often with the first or second urine of the morning.
- Drink a consistent amount of fluid each day so that your urine is concentrated to a similar degree for each day’s test. Very dilute urine may not be adequately concentrated for LH detection (your urine will need to be yellow in color, not clear like water).
- Be certain to discuss unusual result patterns with your provider.
Fertility Topics to Explore
Your fertility journey is unique, and understanding each step can help you feel more in control. This section provides clear, reliable information about fertility testing and treatments offered at First Choice OBGYN—from ovulation tracking and medication use to intrauterine insemination (IUI). Our goal is to give you the knowledge and reassurance you need as you move forward with care.