How Many Donor Eggs Do I Actually Need? What the Science Says

This is one of the most common questions intended parents ask, and one of the hardest to get a straight answer to. Below, we break down the actual research combined with our program statistics to help you understand how many eggs you should plan for based on your family goal.

How many donor eggs do I need for IVF?

With a donor under 35, it typically takes about 4 mature eggs to reach one genetically normal (euploid) embryo, the type most closely linked to a successful pregnancy.

What the research says

This 2024 study analyzed 2,660 IVF-PGT-A treatment cycles, the largest dataset of its kind, to determine how many eggs are needed by age to obtain at least one euploid embryo.

If you're considering IVF with your own eggs, this same research can help you weigh your odds against what donor eggs would offer.

How donor eggs change the math

The numbers tell a powerful story about why using a younger donor matters: at 42, you might require ~23 of your own eggs to produce a single genetically normal embryo, while that same result can typically be achieved with just ~4 eggs from a donor under 35.

Donors are also screened for high ovarian reserve, meaning they typically produce more eggs per retrieval, on top of a higher share being chromosomally normal.

How many donor eggs should I purchase?

It depends on how many kids you're hoping for. Here's a rough breakdown by family goal:

If you would prefer the option to choose your baby's sex, you'll want to aim for roughly double your target embryo goal.  

What our program outcomes tell us

The research above gives us a strong benchmark,  and it lines up closely with our own tracked outcomes since 2012.

Fresh Matching Program outcomes

Across Fresh Matching cycles from 2012-2025, our donors have averaged:

28.9 eggs retrieved → 22.6 mature → 18.2 fertilized → 7.2 euploid embryos

That's about 3 mature eggs per euploid embryo — right in line with the research, if not a bit more efficient.

Frozen Egg Bank outcomes

Our Frozen Egg Bank cohorts are built around this same data: a standard lot is 6 eggs. In practice, standard lots from 2012–2025 have produced at least one blastocyst for 81.1% of patients, and two or more for 60.5%.

Every cohort comes with a Blastocyst Embryo Guarantee — at least one blastocyst by day 7. One distinction worth knowing: a blastocyst isn't automatically a euploid embryo. The two are confirmed separately, and only PGT-A testing can confirm the latter. 

Also important to note: you're not locked into buying in fixed increments of six. If your selected donor has extra eggs available, you can often purchase more than a standard cohort. (More on how that works in the FAQ below.)

Why more than one embryo often makes sense

A genetically normal embryo doesn't guarantee a pregnancy on the first try — which is why most intended parents plan beyond the bare minimum, especially if they want more than one child.

Trying again with a second or third embryo raises your overall odds substantially, even though no single attempt is guaranteed. Another study shows implantation rates were 69.4% on the first transfer, 59.3% on the second transfer, and 59.2% on the third transfer — but the cumulative pregnancy rate reached 94.9% by the third attempt.

What this means for your family-building goals

One child, using a donor under 35? A standard 6-egg cohort is a solid research-backed starting point.

More than one child? Fresh Matching is usually more efficient, since you get all mature eggs from that one retrieval.

Using your own eggs, 38 or older? This is typically where the math starts favoring donor eggs.

Ready to take the first step?

Explore detailed donor profiles on our online database,  then your dedicated case manager can help you figure out what makes sense for your specific goals and budget.

FAQ

How many eggs do I need for IVF?

It depends on how many kids you're hoping for. Based on the largest research available on this exact question and our own program outcomes, here's what we recommend:

Do donor eggs really lead to higher success rates?

Yes. Per SART's 2023 National Summary Report, a woman using her own eggs over 42 has a 4.1% live birth rate per retrieval. With donor eggs, that rises to 37.9–46.6%. Two compounding factors drive this: donor eggs are more likely to be chromosomally normal individually, and donor cycles also typically retrieve more eggs overall, both of which stack in favor of a successful outcome.

Can I use the Frozen Egg Bank for more than one child?

Yes. A standard cohort is six eggs, but you're not limited to increments of six — if your donor has extra eggs available, you can purchase more. If she doesn't have enough, we can ask if she's open to cycling again, or help you find eggs from a second donor. For three or more children, Fresh Matching is usually more efficient.

How many euploid embryo transfers until success?

Research presented by RMA/IVIRMA at the 2019 ASRM annual meeting tracked 4,515 patients through up to three consecutive single euploid embryo transfers. Per-transfer implantation rates were 69.4%, 59.3%, and 59.2% — but cumulative pregnancy rate hit 94.9% by the third attempt.

What's the difference between a blastocyst and a euploid blastocyst?

A blastocyst is an embryo that's reached a developmental stage, typically day 5–7, splitting into two cell types that become the fetus and placenta. Euploid means it has the right number of chromosomes. These aren't the same thing — a well-developed blastocyst can still test genetically abnormal. The two get linked in practice because PGT-A requires a biopsy, only safe once an embryo reaches blastocyst stage.

How many donor eggs are retrieved in a typical cycle, and how many fertilize?

At Donor Nexus, Fresh Matching donors average 28.9 retrieved, 22.6 mature, and 18.2 fertilized (about 80%). Our Frozen Egg Bank sees 83.1% fertilization after thaw — both notably higher than general clinical benchmarks (Cambridge NHS cites ~60% fertilization for frozen donor eggs).

Where's this data from?

Rodríguez-Varela C, et al. Fertility and Sterility. 2024;122(4):658–666. DOI: 10.1016/j.fertnstert.2024.06.002 — plus Donor Nexus program outcomes (2012–2025), Cambridge University Hospitals NHS Foundation Trust patient guidance, RMA/IVIRMA research presented at ASRM 2019, and SART's 2023 National Summary Report.

This article is for general educational purposes and reflects published research and Donor Nexus's own program outcomes. It isn't personalized medical advice. Every individual's situation, including egg and embryo counts, success rates, and the right program for your goals, depends on factors specific to you. Talk with your case manager and treating physician before making decisions about your fertility treatment.