With the increasing use of genetic testing in IVF treatment, the concept of a mosaic embryo has become one of the most common terms couples encounter. This term, which often appears in reports following genetic testing, can be confusing for many patients.

So, what does a mosaic embryo mean, is there a chance of pregnancy, and is it suitable for transfer?

What Is a Mosaic Embryo?

A mosaic embryo is an embryo in which some cells have a normal chromosome structure, whilst others exhibit chromosomal variations.

In other words:

• Some of the embryo’s cells are healthy
• Others, however, are genetically different

This situation is usually caused by cell division errors occurring during the early stages of embryo development.

How Is a Mosaic Embryo Detected?

Mosaic embryos cannot be identified using standard embryo assessment methods, but rather through advanced genetic testing.

One of the most important methods in this regard is NGS (Next Generation Sequencing) technology, which enables the detection of mosaic structures by analysing the genetic makeup of embryos in detail.

Can a Mosaic Embryo Be Transferred?

This is one of the issues patients are most curious about.

Mosaic embryos can be transferred in certain circumstances. However, this decision is assessed by specialists based on:

• The degree of mosaicism
• The affected chromosome
• The patient’s overall condition

Not all mosaic embryos carry the same level of risk. Therefore, the decision-making process is always tailored to the individual.

Can a Pregnancy Occur with a Mosaic Embryo?

Yes, healthy pregnancies can be achieved with some mosaic embryos.

During embryo development, some abnormal cells may disappear over time, or healthy cells may become dominant. For this reason, a mosaic embryo is not entirely deemed ‘unusable’.

However, the pregnancy must be monitored more closely.

Can a Healthy Baby Be Born from a Mosaic Embryo?

Studies indicate that certain mosaic embryos can result in a healthy birth.

However, the risk is not entirely eliminated. For this reason:

• Genetic counselling
• Prenatal tests
• Close monitoring are of great importance.

The Difference Between a Mosaic Embryo and a Normal Embryo

In normal embryos, all cells are genetically identical.

In mosaic embryos, however, there are differences between the cells. This difference may affect the embryo’s developmental potential.

Is a Mosaic Embryo Observed in Every Patient?

No. A mosaic embryo is not observed in every patient. It is usually detected in embryos that have undergone genetic screening.

For this reason, it is reported more frequently in IVF treatments where advanced genetic testing is performed.

In Which Situations Is a Mosaic Embryo Considered?

Mosaic embryo transfer is generally considered in the following situations:

• When there are no normal embryos available for transfer
• In cases of recurrent IVF failure
• When there is a limited selection of embryos following genetic testing

At this stage, the treatment plan is tailored to the patient’s specific circumstances.

The concept of mosaic embryos has become more common in IVF treatment with the advancement of genetic technologies.

Although it involves certain risks, achieving a pregnancy may be possible when evaluated in suitable patients.

For this reason, decisions regarding mosaic embryos must always be made in consultation with a specialist doctor and a genetic counsellor.