What does estradiol do during IVF?

What does estradiol do during IVF?

For tracking the progress of your in vitro fertilization cycle, estradiol levels have significant importance. To increase the likelihood of a successful IVF procedure, many eggs of good quality have to be taken from the woman. Typically, the goal of the egg collection operation is to obtain 5 to 15 eggs. The quantity of eggs extracted is directly correlated with IVF success rates. 

To “pump” the ovaries into producing enough follicles and eggs, several ovarian stimulation medication programs are employed. In the absence of stimulant medications, the ovaries only produce and release one mature egg per menstrual cycle (month). Follicle-stimulating hormone injections are a common component of stimulation protocols (FSH). (1)

What is a good estradiol level in IVF?

The overall trend and the quantity of developing ovarian follicles are more crucial than the precise levels of your estradiol (E2) throughout IVF. Your estradiol level will be higher the more follicles you have sprouting. 

On the day of the trigger injection, it is sufficient to detect 200–300 pg/mL estradiol per mature follicle. Because not all follicles produce eggs, for instance, an E2 level of 1000 may result in 3-5 mature oocytes at the time of egg extraction

However, in general, your estradiol should rise steadily until it reaches its peak, which in the majority of patients is usually between 1,000 and 4,000 pg/mL. 

The serum E2 levels at the beginning of your IVF cycle (day 3 of the cycle) should be around 80 pg/mL. Estradiol levels after the end of stimulation (the day of hCG delivery) can range from 200 pg/mL (if there is only one developing follicle) to 5,000 pg/mL. (if you have more than 20 growing follicles). 

However, even with a comparable number of follicles, estradiol levels might vary greatly from person to person. (2)

How quickly do levels of estradiol rise? 

Every two days, estrogen levels rise by 50% to 100% on average. A 50 pg/mL estrogen level at the beginning of an IVF cycle, for instance, will rise to 75–100 pg/mL by day 3 of stimulation. Your E2 level will rise more quickly and with greater estrogen production when you have more follicles. (3)

How is IVF stimulation followed?

It is aimed to stimulate the mother candidate to have at least 4 follicles with a diameter of 14-20 mm. Ideally, there should be at least 8 follicles between 13-20 mm. The goal is to get a good number (about 8-15) of quality eggs.

The size of growing follicles and blood hormone levels are monitored. Ultrasound is used to measure follicles. Estrogen hormone blood levels are important. Estradiol levels are usually below 60 pg/ml at the start of the cycle and rise significantly as more follicles develop.

Peak estradiol levels in IVF during hCG are usually between 1000 and 4000 pg/ml. The stimulating process usually takes about 8-10 days. (4)

What is the role of estradiol in IVF?

In IVF, estradiol plays a variety of crucial roles. The following list covers estradiol’s crucial roles. 

In order to prepare the uterus for embryo implantation, it thickens the lining. It aids fertility doctors in determining how you react to IVF in Turkey stimulation and how many oocytes you can expect to harvest during oocyte retrieval. It is crucial for maintaining pregnancy and endometrial receptivity. (5)

Potential Concerns with Estradiol Levels During IVF

Initially, estradiol levels reflect follicular development, serving as a key indicator of ovarian response to stimulation. Consequently, physicians adjust medication regimens based on these hormonal readings, striving for an equilibrium conducive to successful implantation. Elevated estradiol levels, while sometimes signaling robust follicular activity, can also herald ovarian hyperstimulation syndrome. This condition potentially compromises egg quality and the endometrium’s ability to support implantation. On the flip side, low estradiol levels might indicate inadequate follicular growth, posing challenges to achieving optimal egg retrieval outcomes. Thus, the management of estradiol levels is a delicate balancing act:

  • High levels can signify overstimulation, risking egg quality and endometrial receptivity.
  • Low levels may reflect poor follicular development, affecting the number of viable oocytes.

Throughout this process, the goal remains to maintain estradiol within a range that supports both effective ovarian stimulation and the nurturing environment necessary for embryo implantation. Adjustments to medication, therefore, are not merely reactive but are strategically planned to enhance the prospects of a successful pregnancy.


Pereira, N., Reichman, D. E., Goldschlag, D. E., Lekovich, J. P., & Rosenwaks, Z. (2015). Impact of elevated peak serum estradiol levels during controlled ovarian hyperstimulation on the birth weight of term singletons from fresh IVF-ET cycles. Journal of assisted reproduction and genetics, 32, 527-532.

Leave a Reply

Your email address will not be published. Required fields are marked *

2nd Opinion
2nd Opinion