What is preimplantation genetic diagnosis (PGD), and how does it work?
Preimplantation genetic diagnosis (PGD) is a test done on embryos created by IVF, before any embryo is transferred to the womb. A few cells are taken from each embryo and analysed to see whether it carries a specific inherited condition that already runs in the family. Only embryos that are not affected are chosen for transfer. The aim is to avoid passing on a serious genetic disease, such as cystic fibrosis, thalassaemia, sickle cell disease, spinal muscular atrophy or Huntington's disease, without having to rely on testing during pregnancy and a possible termination. In current terminology, PGD for a single-gene disorder is called PGT-M, and PGD for chromosome rearrangements is PGT-SR.
This guide explains how the test is done, who it is for, how it differs from routine embryo screening, what the rules in Turkey allow, what it costs on top of IVF compared with the UK, US and Germany, how accurate it is and what the process looks like. It is general information, not a genetic counselling session. See our overview of IVF treatments in Turkey.
How is PGD done step by step?
PGD is not a stand-alone treatment; it sits inside an IVF or ICSI cycle. The usual sequence is:
- Genetic work-up before treatment. The laboratory needs to know the exact variant in the family, often by testing both partners and sometimes relatives, and builds a test for it. This can take several weeks.
- Ovarian stimulation and egg collection. Hormone injections stimulate the ovaries, and eggs are collected under sedation; see pharmacological stimulation for IVF.
- Fertilisation by ICSI. A single sperm is injected into each egg, which avoids contamination of the test by extra sperm DNA; see IVF with ICSI.
- Embryo biopsy. On day five or six, when the embryo is a blastocyst, a few cells are removed from the outer layer that will form the placenta, not from the part that becomes the baby.
- Freezing and analysis. The embryos are usually frozen while the cells are tested, which takes days to a couple of weeks.
- Transfer. An unaffected embryo is thawed and transferred in a later cycle.
PGD vs PGT-A: what is the difference between diagnosis and screening?
The two are often confused. PGD (PGT-M) looks for one specific condition that you know you carry. PGT-A, sometimes still called PGS, counts the chromosomes of every embryo to find those with too many or too few, with the aim of improving the chance of a pregnancy that continues; it is not aimed at a known family disease. PGT-SR checks embryos when a parent carries a balanced chromosome rearrangement. Some clinics combine PGT-M with a chromosome count, and our guide to PGT-A embryo testing covers the screening side. A genetics specialist should explain which test, if any, applies to you.
Is preimplantation genetic diagnosis allowed in Turkey, and who can have it?
Turkish regulations allow preimplantation genetic testing for couples at risk of a serious inherited disease and in certain cases of chromosomal rearrangement, and they prohibit selecting an embryo's sex for non-medical reasons. Sex selection is only permitted where it is part of avoiding a sex-linked genetic disease. PGD is typically recommended if you or your partner carry a recessive condition and both are carriers, have a dominant condition such as Huntington's disease, carry a balanced translocation, have had a child with a serious genetic condition or are a family at risk of an X-linked disease. It is also used to find a tissue match for an existing sick sibling in some countries; ask whether this is allowed and offered. You will normally need documents such as a genetic report and the family's test results.
How accurate is PGD, and does it work?
When a well-validated test is available, PGD is highly reliable at identifying embryos affected by the family condition, and it allows many couples to have an unaffected child without prenatal diagnosis. It is not perfect. A very small proportion of results can be wrong, because only a few cells are tested and some embryos have a mix of normal and abnormal cells (mosaicism), so professional guidelines recommend confirming the diagnosis with an amniocentesis or chorionic villus sampling during pregnancy. PGD does not raise the chance of pregnancy, and fewer embryos may be available for transfer after testing. It also tests only for the condition named, not for every possible genetic problem. Treat any promise of a guaranteed healthy baby as a red flag.
Preimplantation genetic diagnosis (PGD) cost in Turkey compared with the UK, US and Germany
The ranges below are approximate and show the genetic testing add-on only: the embryo biopsy, laboratory test design and analysis. The IVF or ICSI cycle, medicines and embryo freezing are charged on top. They are not hospital quotes.
| Country | Approximate cost range (PGD testing add-on) |
|---|---|
| Turkey | €1,500 – €4,500 |
| United Kingdom | €2,500 – €6,000 |
| United States | €4,000 – €10,000 |
| Germany | €3,000 – €7,000 |
What changes the price: whether a test for your specific variant already exists, the work to design a new one, the number of embryos tested (laboratories often charge per embryo), the type of condition and whether a chromosome count is added. A package should list the genetic counselling, the family test design, the biopsy and analysis per embryo, and the IVF elements. Ask what is charged if no embryo is suitable, and whether another cycle needs a new test design.
How long does the PGD process take, and how long do I stay in Turkey?
Allow several weeks to months in total. The genetic work-up can be done remotely before you travel. The stimulation and egg collection phase takes about two weeks, with about ten to twelve days of injections, and most couples need to be in Turkey for roughly ten to fourteen days for scans, egg collection and fertilisation; the embryos are then biopsied and frozen. A frozen embryo transfer happens in a later cycle, either on a second trip of a few days or after you freeze and ship embryos, according to the clinic's policy. You should also plan for several attempts, as one cycle does not always produce an unaffected embryo. Further details of the transfer are in our guide to embryo transfer.
Who is a poor candidate for PGD, and what are the alternatives?
| Option | Best suited to | Typical limits |
|---|---|---|
| PGD with IVF | Couples who want to avoid a known serious inherited disease before pregnancy | Needs IVF; no guarantee of an unaffected embryo or a pregnancy |
| Prenatal diagnosis (CVS or amniocentesis) | Natural pregnancy with a known risk; no IVF required | Result comes during pregnancy and may lead to a difficult decision |
| Donor egg or sperm | When the carrier is one partner and the couple chooses to avoid the variant | Genetic link to one partner is lost |
PGD is less suited when the egg reserve is very low and only a few embryos are expected, when there is no identifiable gene variant or when a couple does not want IVF. Adoption and living without testing are also valid choices. A clinical geneticist should help you weigh these before you commit.
What are the risks of PGD?
PGD carries the risks of IVF, including ovarian hyperstimulation syndrome, bleeding or infection after egg collection, multiple pregnancy and the emotional strain of a long process. The biopsy itself may slightly lower the embryo's chance of implanting, though studies of blastocyst biopsy have not shown clear harm. Misdiagnosis is rare, but not impossible. Having no unaffected embryo is a real possibility. Professional bodies such as ESHRE and the HFEA in the UK publish patient information on these points. Ask the clinic about its own diagnostic error rate and how it tracks births.
How do I choose a clinic and genetics laboratory, and what should I ask?
PGD depends on two teams: an IVF clinic and a genetics laboratory. Ask who performs the biopsy and who runs the test, whether the laboratory has validated tests for your variant, whether it shares its accreditation and quality information and whether a clinical geneticist counsels you before and after. Red flags include a price without a genetic report review, promises of a healthy baby or gender selection outside the medical rules and unclear information about who analyses your embryos. Read how our process works and send your genetic report through the free quote page. Questions to ask:
- Is a test for my specific variant already validated, or does one need to be built?
- How many embryos do you biopsy and test, and what is the price per embryo?
- What is your misdiagnosis rate, and do you advise confirming in pregnancy?
- Are embryos tested in-house or shipped to another laboratory?
- What happens if there is no unaffected embryo?
Hospitals with IVF & Fertility in Turkey
Frequently asked questions
PGD is a test on IVF embryos that checks for a specific inherited condition running in the family. A few cells are taken from each embryo, and only unaffected embryos are chosen for transfer.
PGD (PGT-M) looks for one known inherited disease. PGT-A counts the chromosomes of each embryo to find those with extra or missing chromosomes, and it is not aimed at a known family condition.
Yes, for couples at risk of a serious inherited disease and certain chromosome rearrangements. Selecting an embryo's sex for non-medical reasons is not permitted.
The testing add-on costs approximately €1,500 to €4,500 in Turkey against about €2,500 to €6,000 in the UK, on top of the IVF cycle. The price depends on the condition, test design and number of embryos.
It is highly reliable for the condition tested, but not perfect, because only a few cells are analysed. Guidelines recommend confirming the result with prenatal testing during pregnancy.
Cells are taken from the layer that becomes the placenta, not the baby. Studies of blastocyst biopsy have not shown clear harm, though a small effect on implantation cannot be ruled out.
Allow several weeks to months. The genetic work-up comes first, then about two weeks of stimulation and egg collection, then testing and a frozen embryo transfer in a later cycle.
No. It reduces the chance of the tested condition but tests only for that condition, can rarely give a wrong result and cannot guarantee a pregnancy.
In Turkey it can be considered only to avoid a sex-linked genetic disease, not for family balancing or preference. Anyone offering non-medical sex selection should be treated with caution.
Most couples spend about ten to fourteen days for stimulation, egg collection and fertilisation. A frozen embryo transfer later needs a shorter trip, depending on the clinic's protocol.