What does Day 3 FSH say about my ovarian reserve?
One of the first questions that come to your mind when a woman has trouble conceiving is: “Are my ovaries working properly?” Evaluating your ovarian reserve is one of the first tests that your fertility doctor will order to determine the next step in your fertility journey.
The Day 3 FSH test is a blood test that measures the level of the follicle stimulating hormone (FSH) in your blood stream on the third day of your menstrual cycle. FSH, released by the pituitary gland in your brain, helps follicles grow and mature. Your level of FSH is controlled by the ovaries and can be an indicator of your ovarian reserve.
Here’s why: As they grow and mature, healthy follicles release hormones (like estrogen and inhibin) that suppress the release of FSH from the brain and lower the FSH level in your bloodstream. Thus, lower Day 3 FSH levels might mean you have a better ovarian reserve, and higher levels might mean a poor ovarian reserve.
Your doctor will probably also order a blood test measuring your estrogen levels at the same time as the Day 3 FSH test, because a low blood estradiol (estrogen) level confirms that you have correctly estimated your Day 3 FSH. If the estradiol level is higher than 60 picograms per milliliter, you could be further into your cycle than you think. That means your Day 3 FSH blood test may show a higher FSH level than it would have been if you were truly on Day 3. Another situation that can give a high estradiol level is benign ovarian cysts, which would require further evaluation and follow-up.
Unfortunately, there is no way to determine a “normal” baseline level of FSH, and levels vary depending on laboratory processes and your age. When you’re trying to conceive, having Day 3 FSH levels that suggest decreased ovarian reserve is no consolation even though that’s “normal” for your age. Further, doctors have been frustrated with the limitations of Day 3 FSH for decades. Some women with high Day 3 FSH levels get pregnant while others don’t, even if doctors try to interpret Day 3 FSH results in the context of age.
It turns out that Day 3 FSH is a very valuable predictor of IVF success only if it is analyzed together with other health data, such as age, body mass index (a composite of height and weight), reproductive history, male partner data, and clinical diagnosis. Univfy IVF Prediction Tests take into account these differences between individuals to provide you with a personalized prediction of your IVF success.