In vitro fertilization (IVF) is a widely used assisted reproductive technique designed to help individuals and couples overcome infertility. One of the key steps in the IVF process involves stimulating the ovaries using hormones to retrieve multiple eggs. But how many eggs are actually needed for a successful IVF cycle? And does collecting more eggs directly increase the chances of pregnancy?
Let’s explore the relationship between egg retrieval and IVF success rates.
Why More Eggs Are Retrieved During IVF
During IVF, fertility specialists use hormonal stimulation to encourage the ovaries to produce multiple eggs in a single cycle. The goal is to retrieve enough mature eggs to increase the likelihood of forming healthy embryos. This also provides the opportunity to freeze any extra embryos for future use if the first embryo transfer is not successful.
The ultimate aim of IVF is a live birth, and that depends largely on the quality—and not just the quantity—of the eggs retrieved.
Does More Eggs Mean Higher Pregnancy Rates?
Yes, to an extent. Retrieving more eggs improves the chances of having chromosomally normal embryos (known as euploid embryos). These embryos have the highest potential to implant successfully and lead to a healthy pregnancy and live birth.
In contrast, aneuploid embryos (chromosomally abnormal) have a low chance of developing into viable pregnancies and are more likely to result in miscarriage.
Age and Egg Requirements
As a woman’s age increases, the likelihood of producing euploid embryos decreases. This means:
- At age 34, about 5 eggs may be needed to create 1 euploid embryo, and 14 eggs for 2 euploid embryos.
- At age 38, around 10 eggs may be needed for 1 euploid embryo, and 24 for 2 euploid embryos.
This is why collecting a higher number of eggs is especially important as maternal age increases.
The Risks of Collecting Too Many Eggs
While retrieving more eggs can boost success rates, there are potential risks associated with high ovarian response, often due to higher doses of stimulation hormones. These include:
- Ovarian Hyperstimulation Syndrome (OHSS): A potentially serious condition where fluid accumulates in the abdomen or lungs, and can cause low blood pressure, increased blood clotting risk, and even kidney issues.
- Ovarian Torsion: Excessively enlarged ovaries may twist, cutting off their own blood supply—this is a medical emergency requiring immediate surgical intervention.
- Reduced Egg Quality: In some cases, an over-response to stimulation may unexpectedly lead to lower egg quality.
- Hormonal Imbalance: Excessively high estradiol levels can disrupt the timing between embryo development and uterine receptivity, reducing the chances of successful implantation.
Finding the Right Balance: Ideal Egg Count
Clinical studies suggest that the optimal number of eggs to retrieve during IVF is between 8 and 15. Within this range:
- There’s a higher chance of retrieving good-quality eggs
- Fresh embryo transfer is often possible
- Pregnancy rates steadily improve up to around 15 eggs
Retrieving more than 15 eggs doesn’t necessarily increase success and may introduce complications. In cases of hyper-response, fertility specialists often freeze all embryos and postpone the transfer. This is known as a Frozen Embryo Transfer (FET), which can be done in a later cycle after preparing the endometrial lining for better synchronization.
Conclusion
While retrieving more eggs during IVF can improve the chances of pregnancy—especially in older women—it’s important to strike a balance. The aim is not to collect the most eggs possible, but to retrieve a healthy number of high-quality eggs while minimizing risk to the patient.
Each IVF journey is unique, and the stimulation protocol should always be tailored to individual needs, age, and medical history. With a personalized approach and expert guidance, IVF success becomes more attainable.
Struggling with fertility concerns?
Consult Dr. Chandrika Kulkarni, a leading Infertility Specialist at Prashanthi Fertility Center. With years of experience and evidence-based fertility solutions, Dr. Chandrika provides compassionate care to help you navigate your journey toward parenthood.
Book your consultation today and take control of your reproductive health with confidence.
