genetics

When it comes to egg donation, you may be wondering if the blood type of the egg donor matters. While it is not necessary for the donor to have the same blood type as either parent, it’s helpful to understand how blood types work. In this article, we’ll review the blood types, how they are inherited, and when blood type matching matters. 

What are blood types?

Blood types are determined by the presence or absence of certain antigens, or proteins, on the surface of our red blood cells. Blood types include A, B, AB, and O. Blood type A has the A antigen, blood type B has the B antigen, blood type AB has both A and B antigens, and blood type O has neither A nor B antigens.

Within each blood type, there is a positive or negative (A+, A-, and so on). The positive or negative sign next to the blood groups is known as the Rhesus (Rh) factor. Rh factor is independent of blood type. It is determined by the presence or absence of a specific antigen on the surface of red blood cells. If a person has the Rh antigen, they are Rh-positive. If they do not have the Rh antigen, they are Rh-negative. Most people, about 85%, are Rh-positive.

According to the San Diego Blood Bank, the average distribution of the blood types in the United States are:

• O Positive (O +): 38%
  

• O Negative (O -): 7%
  

• A Positive (A +): 34%
  

• A Negative (A -): 6%
  

• B Positive (B +): 9%
  

• B Negative (B -): 2%
  

• AB Positive (AB +): 3%
  

• AB Negative (AB -): 1%
  

How is a child’s blood type determined in egg donation?

A baby's blood type is determined by the combination of genes inherited from the egg and sperm. Each passes on one of their two ABO alleles to the child. The combination of these alleles determines the baby's blood type. For example, if the egg donor is type A and the biological father (or sperm donor) is type B, the baby could be type A, type B, type AB, or even type O. 

Unless both the egg donor and intended father have blood type O, in which case the baby would definitely be type O, you would need a blood test to determine the baby's blood type.

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But remember how we said everyone also has an Rh factor, that plus or minus after the letter? A child inherits one Rh allele from the egg donor and one from the intended father. If both are Rh-positive, then the child will be RH-positive. If both are Rh-negative, then the child will be Rh-negative. If one is Rh-negative and the other is Rh-positive, then the child could be either. 

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Does the egg donor determine the blood type of the child?

The blood type of a child is determined by the combination of genes inherited from the egg and sperm. Each contributes one of two possible alleles (versions) for each gene that codes for the blood type. The Rh blood group system is determined by another gene on chromosome 1 that has two alleles: D and d. The D allele codes for the RhD protein, and the d allele codes for no Rh protein.

While the egg and sperm decide the genetic makeup of the child, they do not have control over the specific alleles that the child inherits. That is determined by the process of meiosis, which randomly selects which sperm or egg cell will fertilize the other.

What is Rh incompatibility?

Rh incompatibility occurs when a pregnant woman (either an intended mother or gestational carrier) who is Rh-negative carries a baby who is Rh-positive. Her immune system may recognize the baby's Rh-positive blood cells as foreign and produce antibodies against them. This can cause her immune system to attack and destroy the baby's red blood cells, leading to a condition called hemolytic disease of the newborn (HDN). HDN can cause serious complications for the baby, including anemia, jaundice, brain damage, and even death. 

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It’s important to know if you’re at risk for HDN. But the good news is that HDN can be prevented by administering a medication called Rh immunoglobulin (RhIg) or Rhogam to the mother or gestational carrier during pregnancy, which helps prevent her body from making antibodies against the baby's blood cells.

If you or your gestational carrier are Rh negative, consult with your doctor about choosing a donor who is Rh positive. 

Is it possible for a child to have a different blood type than both of its parents?

Yup! As you can see in the chart shared  above, there are many cases where a child would have a different blood type from their biological parents. For instance, if the egg donor was blood type A and the intended father was type B, the child could be blood type O.

Why would someone want an egg donor with the same blood type?

There are a couple reasons someone might want an egg donor with a specific blood type.

First, they may want to avoid rare blood types in the rare situation that the child would need a blood transfusion.  Blood transfusions can only be given to individuals with compatible blood types. For example, if someone with blood type A receives a blood transfusion from someone with blood type B, their body may react negatively and cause serious health issues. Remember though, unless both the egg donor and intended father are type O (in which case the only option is for the child to be type O), there is no guarantee that a child will be the same blood type as one parent. 

Second, blood type can also play a role in pregnancy and childbirth. If a mother or gestational carrier is Rh-negative and the baby is Rh-positive, the mother's body may produce antibodies that attack the baby's red blood cells, which can lead to a condition called hemolytic disease of the newborn. However, this is treatable and not a reason to pass on an egg donor.

Third, some parents may want to increase the chances of their child having (or not having) a certain blood type. There is some evidence that certain blood types are more protective against certain health conditions like heart attacks, memory loss, and cancer. 

Lastly, parents who do not plan on telling their child about their donor-conceived origins may want to have a child with similar blood type. Although this is your family and you get to decide how / if  to tell your story, research has shown over and over the importance of openness and honesty in telling children their conception story and telling it early.  

Is it better to find an egg donor who has the same blood type as myself?

So does blood type matter?  It is not necessarily "better" to find an egg donor who has the same blood type as yourself. It’s helpful to know the blood type of the donor, but blood type doesn’t need to be a reason to choose a donor, and most parents have other attributes that are more important to them.

As mentioned above, having an egg donor who is the same blood type as the intended mother or gestational carrier can help reduce the risk of Rh incompatibility between the baby and the intended mother, which can cause serious complications for the baby if not treated. However, blood type matching is not necessary for egg donation, and many successful pregnancies and healthy babies are born from egg donation despite not having a blood type match.

Ultimately, the decision of whether to find an egg donor with the same blood type as yourself should be made in consultation with a fertility doctor, who can provide more information and guidance on the risks and benefits of blood type matching in your specific situation.

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Cofertility is a human-first fertility ecosystem rewriting the egg freezing and egg donation experience. Our Family by Co platform serves as a more transparent, ethical egg donor matching platform. 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 today!

When it comes to starting or expanding a family, many couples and individuals may turn to assisted reproductive technologies (ART) such as in vitro fertilization (IVF) to help them achieve their goal. One aspect of IVF that many patients are offered– whether using their own eggs or donor eggs – is preimplantation genetic testing (PGT). But is it necessary to do PGT testing with embryos made from donor eggs? Let’s dive in and find out. 

What is PGT?

PGT is short for PGT-A, or “Preimplantation Genetic Testing for Aneuploidies,” and you may also hear it referred to as PGS (“Preimplantation Genetic Screening”) or PGD (“Preimplantation Genetic Diagnosis”) which are various forms of testing embryos. 

PGT testing looks at an embryo to see if it contains the correct amount of chromosomes. Embryos with the right number of chromosomes — 46 — are considered “euploid,” and those with extra chromosomes or chromosome deletions are considered “aneuploid.” PGT is a way to screen for genetic disorders in embryos created through IVF before they are transferred to the uterus. 

PGT testing and age

Here’s an annoying fact: the percentage of embryos that are euploid decreases as we get older. So not only do we have fewer eggs as we age, but the chances that any one egg turns into a healthy baby decreases too.

One study of over 15,000 embryos found that the lowest risk for embryonic aneuploidy was between ages 26 and 30, and that older age groups had the lowest chance of a genetically normal embryo. 

As you can see, chromosomal abnormalities of embryos are normally due to the age of the egg (or rather, the age of the mother or egg donor at the time the egg is retrieved). Since donors are under the age of 33 and healthy, embryos made with donor eggs have a good chance of being genetically normal. So, is it still worth PGT testing donor egg embryos? That leads us to the next section…  

The upside of PGT testing donor eggs

There are definitely some benefits to testing donor eggs:

• Gender selection. PGT testing allows for gender selection. Most clinics allow you to know each embryo’s gender, which can be helpful for families that have a preference.
• Rule out sperm issues. PGT testing of embryos made from donor eggs may also be suggested for couples with male infertility, especially if the sperm has shown chromosome translocations or abnormalities.
• Pick the healthiest embryos. PGT can detect genetic disorders such as cystic fibrosis, Tay-Sachs disease, and sickle cell anemia, allowing for the selection of embryos that do not carry these disorders.

The downside to PGT testing

However, a lot of fertility doctors will say it’s okay to pass on genetic testing with embryos made from donor eggs. Here’s why:

• It’s expensive.The cost of PGT can vary depending on the type of testing done and the clinic you're working with, but it can be thousands of dollars. 
• Added time. It can take some testing companies weeks to give you the results. Time goes so slowly during IVF, and adding additional time can be a major downer. 
• False positives or negatives. PGT can be prone to false positives or negatives, meaning an embryo that is genetically normal could be labeled as abnormal, or vice versa. 
• There’s a small risk to the embryo. The biopsy process, which removes cells from each embryo to be sent for testing, has a chance of damaging the embryo. Also because the embryo must be frozen in order to do PGT testing, there’s risk in having to be thawed and unthawed. 

But the biggest downside is that PGT might not even improve the chances of pregnancy for those using donor eggs! Remember that chart you saw above? If embryos are made from donor eggs, where the donor is under 35… the chances of each embryo being euploid is pretty high. 

Let’s look at the data. A 2020 study looked at 1,291 donor-egg cycles across 47 IVF clinics– 262 cycles with PGT testing and 1,029 without. Live birth rates occurred:

• 53.8% of donor-egg cycles with PGT testing 
• 55.8% of donor-egg cycles with without PGT testing

Yes, you read that right. The donor-egg cycles that skipped PGT actually had higher live birth rates than those who paid to have the embryos PGT tested. The researchers concluded that PGT testing in donor egg-recipient cycles does not improve the chance for live birth, nor does it decrease the risk for miscarriage. But it does increase cost and time for the patient. 

Summing it up

PGT can be a useful tool for patients who are at risk for passing on a genetic disorder or have a family history of a particular condition, however it may not be that useful for those using healthy donor eggs. The financial cost, time, false positives or negatives, and risks to the embryo are all important factors to consider. This is definitely a question and conversation you want to have with your doctor who can help you make the best decision. Good luck!

Cofertility is a human-first fertility ecosystem rewriting the egg freezing and egg donation experience. Our Family by Co platform serves as a more transparent, ethical egg donor matching platform. 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. 

Donor egg in vitro fertilization (IVF) is a fertility treatment in which an intended parent uses eggs from an egg donor to have a baby. In this process, the donated eggs are fertilized with sperm from an intended parent or sperm donor in a laboratory to create embryos. Those embryos are monitored by an embryologist while they grow into blastocysts. They are then frozen, genetically tested, and transferred to the uterus of the intended mother (or a gestational carrier) in the hope that it will implant and result in a pregnancy. 

We know that using donor eggs can greatly increase the chances of success for an infertile couple. But how common is egg donation? Let’s dive in.

First, who uses donor eggs?

There are many reasons an intended parent would turn to donor eggs to have a baby:

• Infertility due to low ovarian reserve 
• Repeated IVF failures with own eggs
• Infertility due to recurrent miscarriage
• LGBTQ+
• Genetic mutations
• People without ovaries
• Single males
• Women whose own eggs have been damaged by chemotherapy or radiation treatment

Regardless of the reason, donor eggs are a viable, and increasingly common, path to parenthood. 

How common is donor egg IVF in the US?

The use of donor eggs has been increasing in recent years. While it's hard to know the exact number of egg donation cycles each year, we can get a good estimate through the Society for Assisted Reproductive Technologies (SART), which tracks data for nearly 400 US clinics annually. 

In 2019 there were nearly 20,000 IVF transfers using donor eggs at SART-reporting clinics. That is up 14% from the previous five years. Of those transfers:

• 1,776 used fresh donor eggs
• 2,468 used frozen donor eggs
• 15,294 transferred thawed embryos

How common is donor egg IVF in the UK?

More than 70,000 donor conceived children have been born in the UK since 1991. The total number of babies born via egg donation in 2019 was 1,327, up 88% from 2009. Of those, 83% used a donor egg and the partner’s sperm. The remaining 17% used both donor egg and donor sperm.

How common is donor egg IVF in Australia and New Zealand?

In Australia and New Zealand, there were 3,316 IVF cycles performed using donor eggs (or embryos) in 2017 with 727 live births reported. Of those cycles, 86% used donor eggs and the partners sperm while the remaining used a donor embryo.

How common is donor egg IVF in Europe?

According to data from the European Society of Human Reproduction and Embryology (ESHRE), the number of donor egg cycles in Europe has been steadily increasing in recent years. In 2017, the most recent year for which data is available, there were a total of 28,377 donor egg cycles reported in Europe, representing about 5% of all IVF cycles performed in the region. It is worth noting that these figures do not include data from all European countries, as not all countries report their IVF data to ESHRE.

How common is donor egg IVF in Asia?

In China, egg donation is uncommon. That is because donor eggs can only be used if they are unused leftover eggs from women who underwent IVF. Data collected by The Chinese Society of Reproductive Medicine (CSRM) of 327 fertility clinics from 2013 to 2016 found 1,642 donor egg cycles in that time, a small fraction of the 12 million cycles.

The use of donor eggs globally

Unfortunately there’s no way to know exactly how many donor egg cycles there are globally. 

But according to data from the International Committee for Monitoring Assisted Reproductive Technologies (ICMART), which collects data from 2,971 clinics in 79 countries, there were 161,139 egg donation transfers in 2018.

The use of donor eggs is more common in countries and regions with better access to IVF, and where legal, cultural, or religious beliefs make the use of donor eggs more acceptable. Plus, the use of donor eggs in IVF may be underreported in some countries, as not all countries require procedures to be reported to regulatory agencies.

Donor eggs can increase your chances of success

Around 53 percent of all donor egg cycles will result in at least one live birth. This percentage varies depending on the egg donor, recipient body mass index, stage of embryo at transfer, the number of oocytes retrieved, and the quality of the clinic.

At every age, the chances of birth with donor eggs is better, but those who benefit the most from donor eggs are women over 35 and those with low ovarian reserve. In fact, about one-quarter of women over 40 who succeeded with IVF did so through the use of donor eggs. 

At Cofertility, for those who match with a donor in our fresh egg donation program, the average number of mature eggs a family receives and fertilizes is 12. The number of eggs retrieved varies by patient and cycle, but can be predicted by a donor’s age, AMH, and antral follicle count, all of which will be known to you after the donor’s initial screening. Qualified candidates have an ample ovarian reserve for both their own needs and sharing. Egg share donors also often work closely with a fertility doctor to determine, based on their own medical history, the optimal number of eggs needed for their own future family-building goals. Should it make sense for the donor, they may choose to pursue a second egg-sharing cycle to maximize the chances of success for everyone.

Matching with a donor in our frozen program can provide the opportunity to move forward with your family-building plans faster, as frozen eggs can be fertilized or shipped to your clinic immediately or as soon as the cycle is complete. Donors undergoing frozen cycles complete equally rigorous ovarian reserve testing. While the total number of frozen eggs available will vary based on the donor’s retrieval outcomes, every frozen match is guaranteed to have a minimum of at least 6 frozen eggs.

To learn more about these programs and the differences between them, click here.

Donor eggs: where do I start?

If you are looking to use donor eggs to build your family, we’d love to help. Cofertility is a human-first fertility ecosystem rewriting the egg donation experience. Our Family by Co platform serves as a more transparent, ethical egg donor matching platform. 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 today!

If you are pursuing parenthood via donor egg IVF, you may find yourself drawn to a donor who shares many of your qualities but differs in one significant aspect: ethnicity or race. This scenario, known as transracial egg donation, is actually quite common. While expanding your egg donor search beyond your own race opens up more possibilities for family building, it also comes with unique considerations and responsibilities. This article aims to provide a comprehensive guide to help you navigate this scenario.

There are many reasons why intended parents might consider a donor of a different race or ethnicity. For some, it's a matter of limited options— they may struggle to find a donor who matches their specific ethnic background. While Cofertility’s donors represent over 55 ethnicities, this has historically been the case for intended parents from minority ethnic groups or those with mixed racial heritage. Others may simply feel a strong connection to a particular donor based on her personality, achievements, or values, finding that race becomes a secondary consideration. 

However, parents who choose this path must be prepared to navigate discussions about identity, cultural heritage, and societal perceptions. By approaching these challenges with openness, education, and a commitment to celebrating diversity, families created through transracial egg donation can thrive and contribute to a more inclusive society.

Considerations for intended parents

As you consider matching with an egg donor, here are some things to think about as it comes to race and ethnicity.

1. Family resemblance

One of the primary considerations in selecting a donor who doesn’t look like you is that it may result in a family where the differences in appearance between parents and children are noticeable to others. This visibility can lead to increased attention, questions, and sometimes unwelcome comments from strangers or even well-meaning friends and family. Some parents don’t mind this at all, whereas others prefer to match with a donor that increases the chances of family resemblance (remember, even in families where the child is genetically related to each parent, they can look nothing like their family). 

You’ll want to prepare yourself for these situations and develop strategies to address them in a way that affirms your child's identity and your family structure. Many parents find that open, age-appropriate communication about their family's story from an early age helps children navigate these situations with confidence.

2. Identity and cultural connection

Children born through donor eggs from an egg donor of a different race or ethnicity may grow up with questions about their genetic roots that differ from yours. Some are simply curious while others might struggle with aspects of their identity or feel a disconnect from their genetic heritage. As parents, you’ll want to proactively address these potential challenges.

Experts recommend talking about race and cultural diversity from day one. Make it a priority to expose your child to their genetic culture, even if it's not your own. This might involve learning about and celebrating cultural traditions, reading books that reflect your child's heritage, or seeking out community events that connect with their background.

3. Diverse social circles

If you do match with a donor of a different race or heritage, it's beneficial to ensure that your social circles reflect the diversity of your family. Seek out opportunities to interact with people from various cultural backgrounds, particularly those that reflect your child's genetic heritage. This exposure can help your child feel a sense of belonging and see positive representations of their racial or ethnic background.

Consider joining support groups or social networks for multiracial families or families formed through adoption or egg donation across racial lines. These communities can provide valuable support, shared experiences, and opportunities for your child to connect with others in similar family structures.

4. Education and self-reflection

Before proceeding, it's important to educate yourself about race, racism, and the experiences of people from different racial or ethnic backgrounds. This might involve reading books, attending workshops, or seeking guidance from professionals experienced in multiracial family building.

Engage in honest self-reflection about your own biases, privileges, and attitudes towards race. Consider how prepared you feel to parent a child of a different race and what additional resources or support you might need.

5. Lifelong commitment

Choosing a donor of a different race or ethnicity is a lifelong commitment to honoring and supporting your child's full identity. This means being prepared to have ongoing conversations about race, identity, and family structure throughout your child's life.

It also involves being an advocate for your child in various settings, from schools to social situations. You may need to address racism or microaggressions directed at your child and help them develop strategies to navigate these challenges.

6. Openness and honesty

Experts in the field of third-party reproduction consistently emphasize the importance of openness and honesty with children about their origins. In the case of transracial or cross-cultural egg donation, this openness extends to discussions about race, ethnicity, and genetic heritage.

Consider how and when you'll share information about your child's genetic origins. Many families find that introducing these concepts early and naturally, as part of ongoing family conversations, helps children integrate this information into their sense of self more easily.

Summing it up

Egg donation can be a beautiful way to build your family. However, it's a path that requires careful thought, preparation, and a lifelong commitment to supporting your child's full identity.

As you consider this option, take time to reflect on your motivations, educate yourself about the potential challenges, and seek support from professionals and communities experienced in multiracial family building. Remember that every family's journey is unique, and there's no one-size-fits-all approach.

Ultimately, the decision to pursue egg donation is yours alone. By approaching it with openness, education, and a commitment to honoring your child's full identity, you can create a loving, supportive environment for your child to thrive. Your family's story will be uniquely beautiful, woven with threads of diversity, love, and the shared experiences that bind you together.