How Hopeful Gay Dads Decide Whose Sperm to Use

For gay dads growing their families through egg donation and surrogacy, deciding who will contribute sperm is often one of the most meaningful and sensitive decisions in the process. Whether both partners want a biological connection to their child, or just one plans to contribute genetically, there’s no single right way to go about it.

Some couples know right away what feels best. Others spend a lot of time navigating emotional, practical, and medical questions before landing on a plan. And for many, it’s not only about who contributes sperm, but also how. There are multiple ways to approach fertilization, each with its own implications for cost, family dynamics, and personal identity.

In this article, we’ll walk through the most common options for sperm contribution in egg donor cycles for gay dads: using a single sperm source, splitting the eggs, mixing sperm, or choosing to intentionally not know. We’ll also cover what to consider medically and emotionally, and how this choice connects with another big decision: whether to do a shared or separate egg donor cycle (as discussed in this companion guide).

Single sperm source

In this approach, one partner's sperm is used to fertilize all of the donor eggs. It’s the simplest from a medical and logistical standpoint. Some couples choose this route early in the process, while others come to it after weighing various emotional and financial considerations.

Why this works for some couples:

• One partner has a strong preference to be the genetic parent, while the other partner is completely comfortable not contributing sperm.
• A sperm analysis reveals that one partner’s sample has higher quality or fewer risks.
• The couple plans to use the other partner’s sperm for a future child instead of trying to split one egg donor cycle. Or the other partner already has biological children. 

This route typically makes embryo creation, storage, and embryo transfer planning more straightforward. It also avoids the risk of uneven embryo numbers between partners, which can come up when splitting a cycle.

But it’s worth talking openly about how this decision feels for both partners. Even when there’s agreement, that doesn’t mean there aren’t emotions to process around roles, fairness, and the relationship each parent will have to the child.

Split insemination

Also known as a “shared cycle,” this option involves dividing the donor eggs between the two partners. Half the eggs are fertilized with one dad’s sperm, and the other half with the other’s. While each partner’s sperm will fertilize the same number of eggs (or close to the same number if there’s an odd number of eggs), this doesn’t mean that there will be the same number of embryos made. That is because each egg is different, each sperm is different, and so there’s some randomness in final outcomes. That being said, in a shared cycle, the goal is two sets of embryos, one per partner. 

This option is common among couples who want both dads to be biological parents and are working with one donor cycle to hopefully have two (or more) children. 

Split insemination works best when:

• The donor’s expected egg yield is strong enough to provide viable embryos for both partners.
• Both partners want to be genetic parents to children who share the same egg donor.
• The couple is comfortable with the possibility that embryo numbers or quality may differ between them.
• Both partners have healthy sperm.

This method requires clear communication and alignment on how outcomes will be handled. For more on shared cycle planning, see our article on Shared vs. Separate Egg Donor Cycles: A Guide for Gay Dads.

Mixing sperm

In this method, sperm from both partners are combined and used to fertilize the eggs. While this might sound simple in theory, the reality is a bit more technical and not always recommended by fertility doctors.

When sperm is mixed, you won’t know in advance which partner’s sperm fertilized which egg. If conventional IVF is used (where sperm are placed near each egg in a petri dish), the fertilization process is less controlled. With ICSI (intracytoplasmic sperm injection), where a single sperm is injected into an egg, embryologists can alternate which partner’s sperm they use for each egg—but that typically becomes a form of split insemination, not true mixing.

Why some couples consider mixing:

• They want to leave the outcome to chance, without assigning biological parentage in advance.
• They’re drawn to the idea of removing choice as a factor, viewing randomness as a way to share parenthood equally.

A more controlled version of this approach—Intentional Unknowing—offers a clearer path while preserving the spirit of not assigning parentage in advance.

Intentional unknowing

This approach is gaining traction among gay couples who want both partners to contribute sperm—but prefer not to know which embryo came from whom.

Here’s how it works: Both sperm sources are used to fertilize donor eggs (via ICSI or a similar process). Embryos are labeled without linking them to a specific partner. When it’s time for transfer, the selected embryo is transferred to the surrogate without revealing whose sperm was used. You can ask the doctor to choose an embryo of a specific sex, the highest rated embryo, or to simply choose at random. 

Why couples choose this:

• They want to share the parenting experience fully, without one dad being labeled the “bio” parent.
• They want just one child and can’t decide which sperm to use. 
• They don’t want the child to be raised with different expectations or assumptions based on biology.
• They’re more interested in building a family together than assigning origin stories.
  

Couples who choose this path often spend time thinking about whether they’ll tell their child later on, and if so, how. Some do DNA testing down the line, others leave it open-ended, and some decide not to pursue the information at all.

Other considerations

Here are a few other approaches and questions that may come up as you think through sperm selection:

• Alternating children: Some couples decide one dad will contribute sperm for the first child, and the other for the second. This can be done with the same egg donor (if embryos are banked), or with a new donor later.
• Decision based on testing: One partner may carry a genetic condition, or have borderline sperm quality, which influences the choice.
• Emotional preference: Sometimes one partner simply feels more strongly about contributing sperm, while the other feels more connected to the pregnancy, birth, or parenting in different ways.

Questions to ask yourselves

Choosing whose sperm to use can be a surprisingly layered conversation. Here are a few questions that might help surface what matters most:

• Do we both want to contribute sperm now, or does one of us feel more ready?
• Would knowing who’s the biological parent affect how we feel about parenting?
• How important is it to us that siblings share the same genetic background?
• Would leaving the outcome to chance (or not knowing) feel empowering—or uncomfortable?
• If one of us isn’t the biological parent, how do we want to talk about that with our child later?
• If we choose not to know whose sperm was used, how do we plan to navigate questions our future child(ren) may have about their own genetic identity?
  

Final thoughts

There’s no rulebook for how gay dads should make this decision—and that’s a good thing. Every couple has different values, dynamics, and comfort levels. What matters most is that the process feels respectful and intentional for both of you.

Whether you choose to split the eggs, alternate children, or simply decide together whose sperm to use, this is the beginning of building your family—not a competition, and not a test of fairness. With clear communication and the right support from your clinic and legal team, you’ll land on a plan that reflects what matters most: raising a child you both love, equally and fully.

​​Find an amazing egg donor at Cofertility

At Cofertility, our program is unique. After meeting with hundreds of intended parents, egg donors, and donor-conceived people, we decided on an egg donation model that we think best serves everyone involved: egg sharing.

Here’s how it works: our unique model empowers women to take control of their own reproductive health while giving you the gift of a lifetime. Our donors aren’t doing it for cash – they keep half the eggs retrieved for their own future use, and donate half to your family.

We aim to be the best egg-sharing program, providing an experience that honors, respects, and uplifts everyone involved. Here’s what sets us apart:

• Human-centered. We didn’t like the status quo in egg donation. So we’re doing things differently, starting with our human-centered matching platform.
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• Diversity: We’re proud of the fact that the donors on our platform are as diverse as the intended parents seeking to match with them. We work with intended parents to understand their own cultural values — including regional nuances — in hopes of finding them the perfect match.
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• Lifetime support: Historically, other egg donation options have treated egg donor matching as a one-and-done experience. Beyond matching, beyond a pregnancy, beyond a birth… we believe in supporting the donor-conceived family for life. Our resources and education provide intended parents with the guidance they need to raise happy, healthy kids and celebrate their origin stories.

We are obsessed with improving the family-building journey — today or in the future — and are in an endless pursuit to make these experiences more positive. Create a free account to get started today!

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