Can You Mix Sperm for Surrogacy? A Genetics Guide for Gay Dads

There are many important decisions to make on your journey to parenthood. But for gay dads-to-be embarking on the surrogacy process, one of the first big questions to answer is "Whose sperm are we going to use?" 

In this article:

• Beginning Your Surrogacy Journey
• How to Choose Whose Sperm to Use
• Selecting Your Egg Donor
• IVF for Surrogacy
• FAQs: Surrogacy for Dads-to-Be
• What if we want to have twins?
• Can two dads be related to the same child?
• Can you mix sperm from both partners for surrogacy?
• Looking Towards Your Family's Future

Beginning Your Surrogacy Journey

Here at Illume Fertility, we work closely with dads-to-be as they move through the gestational surrogacy process. After over 20 years supporting gay couples on their path to biological fatherhood, we know that some decisions on this journey are "no-brainers," and others require deep thought and careful discussion. 

One of the first big choices you will have to make is whose sperm will be used to co-create your future child. For gay cis male couples (where both partners were born with testes), either one or both partners could be a genetic intended father, meaning your sperm will be combined with donor eggs in the laboratory to create your embryos. 

But can you mix both partners' sperm together? And how should you decide whose sperm to use? Here's what to consider as you move forward with this part of the surrogacy process. 

How to Choose Whose Sperm to Use 

Even as more gay couples opt to become fathers through surrogacy, deciding whose sperm to use in the fertilization process can still be a psychological stumbling block for many men.

The good news? You won't be navigating all of this on your own.

Expert input from your fertility doctor and surrogacy agency, genetic and/or mental health counselors, and open, honest communication with your partner will help you make this deeply personal decision with clarity and confidence.

There are many important considerations that can factor into the decision-making process, including medical, family, and genetic history, and personal desire to have a biological child.

Note: If one or both partners either 1) knows they don't have a strong desire to be a genetically-linked parent, 2) knows they are sterile, or 3) has a family history of heritable conditions they want to avoid passing on - this decision may already be made.

Step 1: Semen Analysis 

Starting with a semen analysis for both partners is the best first step. The results of this test will provide a detailed view of how healthy your sperm is, and which partner’s sperm is most likely to result in a successful pregnancy. 

You may even discover that you or your partner want to work towards improving your sperm health before moving forward with the IVF and surrogacy process. 

Step 2: Genetic Carrier Screening

While many intended fathers welcome the chance to be genetically connected to a child, there are a few reasons why one might choose to forgo that option. Some dads-to-be simply don’t feel the need to be genetically linked to their child, and are happy to have a partner play that role in their surrogacy journey instead.

In other cases, a family history of disease, mental illness, or other inherited disorders can play into the decision-making process.

Genetic carrier screening (often performed via a simple blood test) can help couples make informed decisions about reproductive options, allowing for early intervention and treatment, if necessary, and reducing the risk of passing on genetic conditions.

Note: While this may seem like a potentially overwhelming process, there are genetic counselors on staff at many fertility clinics to help walk you through each step.

Ensuring Genetic Compatibility

One of the most important considerations in the surrogacy process is genetic compatibility with your chosen egg donor (more on this below). Once genetic carrier screening has been completed, you and your partner will meet with a genetic counselor to discuss any potential concerns about the genetic compatibility of the sperm source and egg donor.

Step 3: Further Discussion & Counseling

If you and your partner are both willing and able to contribute to the creation of your future child, but are still unsure about how to make this decision, additional counseling with a social worker or therapist may be a great next step.

Your fertility clinic or surrogacy agency can connect you with an experienced counselor.

Selecting Your Egg Donor

Same-sex male couples (or any individual or couple without viable eggs) will need to find an egg donor.

There are a variety of ways to find your egg donor match. Your chosen fertility clinic may have an in-house egg donor program (as we do here at Illume Fertility). If you are working with a surrogacy agency, they may also have their own pool of egg donors to choose from.

Some intended parents wish to use a known egg donor, such as a family member or close friend. This can be a wonderful option, but it is important to understand the potential complications that can arise from using a known donor.

If using a known donor is something you would like to consider, be sure to discuss this with your fertility clinic and surrogacy agency. 

Who will be the best egg donor for you?

Many pieces of your surrogacy journey as a two-dad family will look similarly to those with only one sperm source! However, when it comes to egg donor selection, there are a few additional considerations that your clinical care team will help you explore.

Note: If both partners hope to be genetic intended fathers, your clinic will likely guide you towards an egg donor with strong fertility levels, or a donor with a proven history, which gives you the best chance at each having at least one chromosomally-normal embryo. 

For same-sex male couples who both want the chance to be genetically linked to their future children, the surrogacy process is largely the same as it is for other dads-to-be. After connecting with your fertility clinic and selecting an egg donor, you will start the IVF process.

Created with love.

Hear how dads Tim and Steve chose to expand their family from two to four through egg donation and surrogacy, and their advice for other gay dads-to-be.

IVF for Surrogacy

Egg Retrieval & Fertilization

On the day of your donor’s egg retrieval, instead of fertilizing every mature egg with only one partner’s sperm, the embryology staff at your fertility clinic can determine the number of mature eggs retrieved and then split them in half.

This is a process called split insemination or split IVF. Here's how it works: 

Half of your donor's eggs will often be combined with sperm from Partner A in the laboratory, and the other half will be combined with sperm from Partner B. This method doesn't specify which partner's sperm fertilizes the egg, leaving it to chance.

Don’t worry - if an odd number of mature, healthy eggs are retrieved, your doctor will have already asked you which partner’s sperm should be used towards that "extra" egg.

While this is not a guarantee that both you and your partner will end up contributing sperm to the same number of embryos, it is a beautiful way for both partners to play an important role in the creation of your future family.

Note: Even in the best case scenario, attrition is always going to be a natural part of the IVF process. This means that the number of eggs retrieved from your donor will not equal the number of healthy embryos you end up with.

Embryo Development & Transfer

As your embryos grow and develop in the laboratory, your fertility clinic team will keep you up to date regarding how many embryos you have - both total, and per partner.

When it comes to embryo transfer, many dads make an easy decision to transfer the single best embryo into their surrogate’s uterus - no matter the sperm source. This choice offers the best chance of success, as well as a healthy baby.

In the future, when you're ready to embark on a "sibling journey" and expand your family again, you can request that your doctor transfer the best embryo from the other partner if both you and your partner have a desire to be genetically linked to your children. 

FAQs: Surrogacy for Dads-to-Be

Feeling a little overwhelmed? We get it!

There's a lot to consider when preparing for a surrogacy journey. The most important things you can do to set yourself up for success are find an LGBTQ+ experienced fertility clinic, ask lots of questions, and trust your team.

Here are more common questions we get from dads-to-be:

What about twins?

Many hopeful dads begin the surrogacy process asking about twins. While it is possible to transfer one embryo from each partner into your gestational carrier’s uterus, we do not recommend making this decision without professional counseling.

While twins may look adorable on TV in a double stroller, multiple pregnancies carry much higher risks of developmental delays, fetal growth issues, prematurity, and pregnancy complications. Many fertility clinics will no longer support an elective twin pregnancy for the safety of both the babies and the surrogate.

Multiple pregnancies also often have a higher price tag, as the gestational carrier is taking on many additional risks and physical challenges with twins or higher order multiples.

Note: If you'd still like to explore the possibility of twins, talk to your reproductive endocrinologist to learn more about what you should consider.

Can two dads be related to the same child?

Unfortunately, no - as of right now, there is no way for two same-sex cisgender individuals to both be directly genetically linked to the same child.

If you choose to do a split insemination cycle (where each partner’s sperm is combined with half of the same donor's eggs), your future children will be half-siblings, connected by a common egg donor and genetically-linked to each dad.

Some intended parents choose to use a single sperm source (i.e. Partner A), and then use a familial egg donor from Partner B in order to link both family trees together. This can be a beautiful way to grow your family, as long as Partner B has a cousin, sister, or other relative who is an appropriate candidate.

Can you mix sperm from both partners for surrogacy?

Some couples wonder whether they can have their sperm simply "mixed" together so the biological parent remains a mystery. For now, at least, the answer is no. Fertility clinics (and federal laws) require that the partner whose sperm is being used sign consents and legal paperwork, so they must be specifically identified.

A Note On Surrogacy Law

It's important to find a reputable fertility clinic that has experience working with LGBTQ+ couples. They will provide guidance on the process, including the legal and ethical considerations involved in your jurisdiction. Laws regarding surrogacy and assisted reproductive technology (ART) vary widely around the world and even within countries, so professional advice is crucial.

Looking Towards Your Family's Future

There is no right or wrong way to go about this choice.

Whether you decide to use a single sperm source, or two, at the end of your journey lies every parent’s goal -- a healthy child, and a happy family. No matter how that family is formed, your child will grow up knowing that you are both proud parents.

That being said, this decision can be an unexpectedly challenging one! If you or your partner are struggling with the question of "whose sperm to use," many fertility clinics have licensed social workers on staff to help you navigate it together.

How will you share your child's story with them?

Once you have made your choice and moved through the surrogacy process, think about the important task ahead of you: sharing that creation story with your future child. Experts suggest trying out different versions of that story while your child is still young, and continuing to practice until you develop one that you feel comfortable with.

Remember that your child’s understanding will naturally deepen as they grow, so you can give more detail as it feels appropriate. For example, information that a 4-year old might not understand might be helpful for a child of eight or ten to understand their special place in your family.

Some parents refer to their child's donor or gestational carrier by name, others choose a special nickname. Some families maintain lifelong relationships with these special people who helped create their family, while others do not.

Only you get to decide what is right for your family.

As you move through the surrogacy process, you will make many more decisions that shape your future family. But in the end, genetics are just one small piece of the puzzle. The most important part of being a family is the love and care you pour into your children and each other.