How Progesterone (PDG) Tests Can Identify Fertility Challenges and Confirm Ovulation

Tracking your basal body temperature (BBT) is a great way to confirm ovulation through the identification of temperature rises in your body due to increased progesterone production after ovulation.

Historically, BBT readings or a blood test were the only ways to get an idea of adequate progesterone levels. Often, doctors draw a 21-day progesterone level in hopes of catching progesterone after ovulation. This process required a drive to the doctor’s office, an uncomfortable needle-stick, and the chance of missing ovulation.

But there are some challenges with this ovulation tracking approach:

You might not see a BBT spike.
You may miss tracking your BBT for a few days and can’t see your coverline.
You may struggle to track your temperature consistently every morning.
You might suffer from a thyroid imbalance that affects your basal body temperature.

Now, you could visit a reproductive endocrinology clinic, which uses ultrasounds to visualize and track follicle growth and release. But this is expensive and it requires frequent trips to the clinic throughout your menstrual cycle.

Luckily, thanks to advancements in technology, you can now use progesterone testing to confirm ovulation at home, conveniently and cost-effectively.

Measuring Progesterone To Confirm Ovulation

After ovulation, progesterone is responsible for reducing cervical mucus production, increasing body temperature by 04.-1.0 degrees Fahrenheit , preparing the endometrium for fertilized egg implantation, decreasing uterine contractions, and supporting early pregnancy.

The hormone progesterone is measured in blood tests.
Pregnanediol (PdG), the metabolite that comes from metabolized progesterone, is the compound measured with at-home progesterone urine test strips.

PdG test strips are like luteinizing hormone (LH) and hCG test strips: You dip a test strip in a few milliliters of urine and read the results a few minutes later. All three types of fertility tests can be captured, stored and charted through the free Premom Ovulation Tracker app.

Research shows PdG typically begins to rise 24-36 hours after ovulation, and reaches the detection high-level (5 ng/ml) five days after ovulation.

Because this timing is opposite to the LH rise before ovulation day, a progesterone test is usually used to double-check or confirm that ovulation has occurred. This means that if urinary PdG test strips are positive for three consecutive days after the LH has peaked, it can be assumed that ovulation occurred — no more guessing!

PdG strips have also been studied in association with cervical mucus tracking. You can use PdG test strips to confirm ovulation 5-7 days after the disappearance of highly fertile type mucus.

The Luteal Phase and Progesterone

The luteal phase is the second half of the menstrual cycle and is known to be dominated by progesterone, the hormone released with successful ovulation. Without ovulation, the presence of progesterone is highly unlikely. (This may be due to other medical conditions.)

The luteal phase consists of three phases that are similar in length for most women. Progesterone levels increase during the first two phases:

Luteinization Process (early stage)
Progestation Process (middle stage)
Luteolysis Process (late stage)

Again, with PdG testing, progesterone levels that are at least 5ng/mL can be detected and used to confirm ovulation.

PdG can be detected as early as 3 days after ovulation.
PdG levels are typically highest seven days after LH peak.
PdG most often presents itself in significant levels 4-5 days past the LH surge.

When To Use Progesterone (PdG) Testing

If you want solid confirmation of ovulation, adding progesterone (PdG) testing to your cycle tracking regimen can help as you try to conceive. At-home PdG tests are a fantastic option for when you’re not sure the LH test results alone can answer the question: “When do I ovulate?”

This is especially true if you:

Haven’t found any positive ovulation test results at all after several cycles.
Sometimes find positive ovulation test results during some cycles, but not consistently.
Have found LH surges lasting longer than 7 days or have found positive ovulation test results across the whole cycle.
Have an irregular ovulation cycle and menstrual cycle.
Have suffered PCOS (Polycystic Ovary Syndrome) and other potential infertility symptoms.

Here’s how PdG testing works in three different scenarios:

1. You See No LH Surge But See a PdG Spike

If you don’t find an LH surge with an ovulation test, but you find a PDG positive result, you probably ovulated during this ovulation cycle. With that information, you can focus on the following causes:

Your LH surge level is too low to be detected.
Your LH surge is too rapid and has been missed.
Your LH surge is not typically following the pattern of low-high-peak-low, but you have ovulated.

2. You See No LH Surge and No PdG Spike

If you couldn’t find a positive LH surge result and you didn’t get a PdG positive test result, consider tracking your basal body temperature (BBT) and using your BBT chart to find out whether you have ovulated or not. If your BBT chart doesn’t show a spike, visit your doctor to check for an ovulation dysfunction issue. When LH peak and PdG are both missing, it indicates an anovulatory cycle.

3. You See a LH Surge and a PdG Spike

Most fertile women usually find both their LH peak and their PdG peak. Seeing both peaks provides reassurance that your body is ready to get pregnant. If you use the Premom app, it can help to predict both your next ovulation day and period start date.

References

About Dr. Patti Haebe, NMD

Dr. Patti Haebe is the Senior Medical Advisor at Premom Fertility and specializes in preconception care, hormone optimization and integrative fertility. Dr. Haebe received her Doctorate of Naturopathic Medicine from the Sonoran University of Health Sciences and holds a Bachelor's degree in Integrative Physiology from the University of Colorado at Boulder.

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