In this video, you’ll gain a clear and practical understanding of follicle count in IVF — what it tells you about your treatment options, what it doesn’t reveal, and how doctors use it to personalise IVF protocols.
Dr Harry Karpouzis, Founder & Scientific Director of IVF Pelargos Fertility Group, explains the science behind follicle count in a patient-friendly way.
Hosted by Barbara Scott, Chair of the Association of Reproductive Reflexologists and founder of Seren Natural Fertility.
This concept has been around for more than ten years. In the past, before vitrification was available, most embryo transfers were fresh. If you started stimulation in the luteal phase or mid-follicular phase, a fresh transfer was not possible. Freezing techniques at that time could compromise embryo quality.
With vitrification, we now know that freezing does not negatively affect embryos. We can safely freeze embryos, transfer them later in a frozen cycle, and achieve equal or even higher success rates. This is partly because the implantation window in frozen cycles is not affected by high hormone levels.
At the same time, we discovered that there are multiple follicular waves during a single menstrual cycle. This means that later in the cycle, the number of follicles visible on ultrasound may be higher than at the beginning. By starting later, we may gain one or two additional eggs.
We also know that egg number is important, especially in older women, because the more eggs retrieved, the higher the statistical chance of obtaining a chromosomally normal egg. Double stimulation also allows us to gain time by performing two egg collections within one cycle.
Yes. We can freeze embryos and, depending on age, perform PGT-A. If we identify a chromosomally normal embryo, it is extremely valuable and offers very good chances.
If we do not find a normal embryo, we continue. Even without PGT-A, having more eggs and more embryos increases the likelihood of eventually achieving a chromosomally normal embryo.
For example, if a woman is 40 years old and we retrieve two eggs, the chance of one being chromosomally normal is much lower than if we retrieve ten eggs. However, a woman with only two follicles will never produce ten eggs in one cycle. She must repeat cycles and continue embryo accumulation.
Yes, it is more demanding. We are effectively talking about two stimulations and two egg collections in one cycle. The benefit is time.
Instead of waiting for another menstrual cycle to repeat stimulation, the patient continues medication for a longer period and undergoes a second egg collection within the same month. The goal is to obtain more eggs in a shorter timeframe. That is the main advantage.
There is no evidence that double stimulation improves egg quality. Some studies suggested slightly better quality in luteal-phase stimulation, but this is not proven.
For patients with a normal follicle count, there is usually no reason to pursue this approach, as a sufficient number of eggs can be obtained with standard follicular-phase stimulation.
We mainly reserve this strategy for poor responders, older women, or patients who need urgent fertility preservation, such as those preparing for cancer treatment.
In most studies, the dose used is approximately 75 mg of DHEA daily, usually taken for about 2 months.
However, I often see women in their forties delaying IVF to complete a full course of DHEA. Given that we do not have conclusive evidence for its benefit, and knowing that egg number and quality decline with age, I would not recommend delaying IVF for too long solely to take DHEA.
The appropriate approach is usually to take it for around two months before stimulation, but this must be individualised.
Yes. Poor responders often need to bank embryos. If only one or two eggs are retrieved, an embryo may not develop, or it may be abnormal after PGT-A.
If we can perform double stimulation successfully in one cycle, we do so. If not, we may freeze embryos and repeat stimulation in a later cycle when the follicle count appears better.
The timing of embryo transfer is not critical once embryos are frozen. What matters is creating the best possible embryos.
Ideally, the baseline ultrasound should be performed in the first ten days of the cycle, after menstruation begins.
If the scan is done later in the cycle, a dominant follicle or cyst may distort the count. Irregular cycles do not usually prevent assessment, but early-cycle scanning provides the most accurate information for planning stimulation.
There are two major factors here: low follicle count and age. At 44, egg quality is significantly affected.
Most studies suggest that, on average, 15–25 eggs are needed at this age to obtain one chromosomally normal egg. This is an average; some women may be luckier, but statistically, the odds are low.
With four to five follicles, it is unlikely to retrieve enough eggs in one cycle. The chances are not zero, but they are very low. Zero chance applies only in menopause.
The role of the fertility specialist is to be honest about probabilities. If the chances are under 2%, many patients may decide not to continue. Others may still wish to try. Egg donation, in this age group, offers significantly higher success rates.
We always assess the couple as a unit. Mildly reduced morphology alone is not always a major issue, and antioxidants or supplements may help slightly.
If sperm parameters are severely reduced, IVF with ICSI is usually indicated. However, the decision depends on the full clinical picture, including the woman’s age, ovarian reserve, tubal status, and hormone levels.
In some cases, less invasive options such as IUI may still be appropriate. Individualised assessment is essential.
Even with a good follicle count, chances decline significantly after age 45 due to egg quality. When a low follicle count is combined with advanced age, the situation becomes even more difficult.
Egg quality depends almost entirely on age. Follicle count affects quantity, not quality.
We usually cannot significantly increase egg number. Treatments such as ovarian PRP or stem-cell approaches are experimental. Some studies suggest modest improvements in follicle recruitment and AMH, but these are not miraculous treatments.
For example, PRP may increase follicle numbers from two or three to five or six, but we do not have conclusive evidence that this increases live birth rates or improves egg quality.
Other options such as DHEA or growth hormone have limited and inconclusive evidence. Age remains the dominant factor.
At Pelargos IVF, we have a day-5 transfer policy. In a good laboratory, there is no benefit to day-3 transfer.
If an embryo cannot reach day 5 in optimal laboratory conditions, it is highly unlikely it would have resulted in a pregnancy if transferred on day 3. Day-5 embryos undergo natural selection and offer higher implantation potential.
The goal is to transfer embryos with the highest chance of success, not simply to transfer embryos earlier.
