Freezing Your Eggs: Why Carrier Screening is an Important First Step

Egg freezing has become an empowering option for women who want to preserve their fertility for a variety of personal or medical reasons. 

Egg freezing has increased in popularity over the last decade with a study from Johnston et al., 2024, finding a 938% increase in the number of Australian and New Zealand women choosing to undergo egg freezing between 2012 and 2022¹.

This process offers individuals the chance to store healthy eggs now and use them in the future, allowing flexibility when it comes to family planning.

Currently the mean age of women freezing their eggs is 37². However, this age is only decreasing as younger women are realising the safety net egg freezing provides to their pregnancy journey.

While this procedure provides a wonderful choice, it’s important to take necessary steps beforehand to ensure you’re fully informed about potential genetic factors that could impact your future children.

One of the essential pre-screening steps is carrier screening, if you have a partner.

Why is Carrier Screening Important for Egg Freezing?

Carrier screening is particularly important for women considering egg freezing as it identifies if you carry genetic mutations for specific inherited conditions that could potentially be passed on to their future children.

While this might seem like a step for later down the line when you’re actually planning to have children, screening before freezing your eggs has several advantages.

Informed Decision-Making

Carrier screening allows you to gain insight into your genetic profile allowing you to access enhanced reproductive autonomy³.

If you’re found to be a carrier of a specific genetic condition, you can be proactive in planning for your future family. For example, you may decide to partner with a fertility clinic that offers genetic testing for embryos to ensure any future pregnancies are free of certain genetic conditions.

Knowing your carrier status helps you make more informed choices, reducing uncertainty about potential genetic risks. This can be especially valuable if you’re freezing your eggs for medical reasons, such as undergoing cancer treatment or having a family history of early menopause.

Better Outcomes with Fertility Clinics

Many fertility clinics now recommend carrier screening as part of the egg-freezing process.

Current advanced technology now enables up to an 80% chance of successful egg fertilisation through egg freezing⁴.

Clinics are better equipped to guide you on next steps, such as testing potential future partners for compatibility or offering additional testing for your eggs if you decide to proceed with in vitro fertilisation (IVF) later on.

What is Carrier Screening?

Carrier screening is a type of genetic test that analyses a person’s DNA for specific mutations associated with inherited conditions.

Being a carrier means you have one copy of a gene mutation for a recessive genetic condition and one normal copy of the same gene. As you have one copy of that is normal and one copy of the mutation gene, you ‘carry’ the condition but you do not have the condition yourself.

This does not impact your health directly, however, if you and your future partner both carry a mutation for the same genetic conditions, there is a higher chance your child could inherit the condition.

Carrier screening typically looks for genetic mutations linked to common conditions like Cystic fibrosis, Fragile X Syndrome, and Spinal Muscular Atrophy. However, extended and comprehensive carrier screening panels are also available that screen for hundreds of genetic conditions.

How Does Carrier Screening Work?

Carrier screening is a simple and typically non-invasive process. The test can be performed through a cheek swab (like with Lumi Health) or via blood, which is sent to a laboratory.

Using NATA Accredited laboratory testing processes, your sample will be analysed to identify if you and your partner being tested share any genes linked to the tested genetic conditions.

Once analysed, the lab provides detailed results to you that can be shared with you and your referring healthcare provider. Your healthcare provider can walk you through the findings and discuss any follow-up steps.

If you receive a high risk or increased chance result in your carrier status, you may have the option to speak with a genetic counsellor. A genetic counsellor can help explain the results in depth, answer any questions, and outline options based on your unique genetic profile.

With clear guidance, you’ll be better prepared to take the next steps.

Next Steps After Carrier Screening

If carrier screening reveals that you carry a genetic mutation, don’t panic. Instead, consider consulting with a genetic counsellor who can guide you on next steps, such as:

• Partner Testing
  If both you and your future partner are carriers of the same genetic mutation, you can explore options like IVF with preimplantation genetic testing (PGT) to select embryos that are not affected by the condition.
• Embryo Testing
  If you eventually decide to use your frozen eggs through IVF, embryo testing may be an option to help ensure your future child does not inherit any genetic mutations.
• Medical Guidance
  Even if you don’t plan to have children soon, your carrier status is useful information for future health planning.

Considering IVF? Learn more about IVF and Carrier Screening!

References

1. ¹ Johnston, M., Fuscaldo, G., Sutton, E., Hunt, S., Zander-Fox, D., Rombauts, L., & Mills, C. (2024). Storage trends, usage and disposition outcomes following egg freezing. Reproductive Biomedicine Online, 48(4),103728. https://doi.org/10.1016/j.rbmo.2023.103728
2. ² Kakkar P, Geary J, Stockburger T, Kaffel A, Kopeika J, El-Toukhy T. Outcomes of Social Egg Freezing: A Cohort Study and a Comprehensive Literature
   Review. J Clin Med. 2023 Jun 21;12(13):4182. doi: 10.3390/jcm12134182. PMID: 37445218; PMCID: PMC10342811.
3. ³ Manuelli, M. (2021). Carrier Screening for Women Undergoing Elective Oocyte Cryopreservation (EOC): A Look at Practice Among Reproductive Endocrinologists at an Academic Fertility Clinic.
4. ⁴ Melbourne IVF (n.d.) Egg freezing success rates.