Georgia Preimplantation Genetic Diagnosis Explained: Indications, Procedure, and Considerations

Consultation Scenario: A Woman Carrying the Polycystic Kidney Disease Gene

38 years old, normal bilateral ovarian reserve, AMH 2.1 ng/mL, husband's semen analysis normal. The woman's family has a history of Autosomal Dominant Polycystic Kidney Disease (ADPKD); her father and two uncles entered end-stage renal disease around age 50. She wishes to have a healthy child and avoid passing on the pathogenic gene. After learning about domestic PGT policies, she noted that Georgia might offer advantages in legal approval and cycle flexibility, and inquired about undergoing preimplantation genetic diagnosis there. Below, we systematically address this patient's questions from a clinical practice perspective.

Is PGT Available in Georgia?

Yes. Currently, 3 to 4 licensed reproductive centers in Georgia are capable of performing preimplantation genetic diagnosis, primarily using Next-Generation Sequencing (NGS) and array Comparative Genomic Hybridization (aCGH). These centers can offer PGT-A (aneuploidy screening) and PGT-M (monogenic disease diagnosis). ADPKD, caused by mutations in the PKD1 or PKD2 genes, is a monogenic disease theoretically eligible for PGT-M, but family validation and probe design must be completed first.

Who is Suitable for PGT in Georgia?

• One or both partners carry a clear monogenic pathogenic mutation, and the mutation is within the detection panel of the collaborating laboratory in Georgia.
• Female age ≥ 35 years, with a history of recurrent embryo chromosomal abnormalities or repeated implantation failure, seeking PGT-A to reduce miscarriage risk.
• Carriers of structural abnormalities such as balanced translocations or Robertsonian translocations, requiring PGT-SR (structural rearrangement) to select normal or balanced embryos.
• Patients facing restrictions in domestic genetic disease approval or long cycle waiting times, who can afford the overseas cycle costs and travel arrangements.

Who is Not Suitable?

• No clear genetic indication, only for sex selection or "eugenic" purposes – Georgian law prohibits non-medical sex selection.
• Very low ovarian reserve (AMH < 0.5 ng/mL, antral follicle count < 3), making it difficult to obtain enough eggs for biopsy.
• Pathogenic gene not yet identified, or incomplete family pedigree preventing mutation site validation; initiating PGT-M prematurely may lead to diagnostic failure.
• Severe uterine abnormalities or uncontrolled systemic diseases that do not meet transplantation criteria.

Physician's Perspective: Key Points in PGT Clinical Decision-Making

In reproductive medicine practice, PGT is not a panacea. First, the mutation type and inheritance pattern of the pathogenic gene must be confirmed. For ADPKD, about 85% are caused by PKD1 mutations and 15% by PKD2, with the possibility of de novo mutations. The patient must provide a blood sample and genetic report from the proband (usually an affected first-degree relative) for the Georgian laboratory to design specific probes. Without family validation, only PGT-A for chromosomal screening is possible, which cannot rule out monogenic diseases. Secondly, embryo biopsy can cause about 5% to 10% of blastocysts to stop developing due to operational damage, requiring patient psychological preparation. Additionally, PGT cycles in Georgia are typically linked to fresh or frozen-thawed embryo transfers. If waiting for genetic results after biopsy (about 2-4 weeks), all embryos must be frozen, which may slightly reduce endometrial receptivity during the transfer cycle.

Differences Between Countries: Georgia vs. China vs. USA

Georgia's advantages lie in flexible approval and relatively lower cycle costs, but its disadvantage is limited laboratory scale, which may require longer probe customization time for rare mutations. Before choosing, patients should confirm the qualifications and case volume of the collaborating genetics laboratory with the reproductive center.

Easily Overlooked Details

Biopsy Timing and Embryo Survival

Most centers in Georgia perform laser-assisted biopsy on day 5 or day 6 blastocysts, removing 5-6 trophectoderm cells. Biopsied blastocysts must be immediately frozen (vitrified). Data suggest that the survival rate after thawing for biopsied and frozen blastocysts is about 85%-90%, slightly lower than the >95% rate for non-biopsied blastocysts. Embryos with higher post-biopsy scores should be prioritized for transfer.

Genetic Counseling and Legal Document Notarization

Georgia requires patients to provide all original genetic reports translated into English or Russian, certified by a local notary. If reports are over one year old, repeat blood sampling for verification may be required. Additionally, if carrier screening results (e.g., SMA, thalassemia) reveal other pathogenic genes, the law allows simultaneous testing, but additional informed consent is needed.

Mosaicism Report Interpretation

Georgian laboratories typically report the mosaicism percentage (e.g., 30% mosaic). For mosaic embryos, local practice often follows international standards: >50% mosaic is usually discarded; 20%-50% may consider re-biopsy or combined prenatal diagnosis; <20% can be considered normal, but with a risk of false negatives. Patients must understand this decision-making process.

Actual Procedure: From Consultation to Transfer

Phase 1: Genetic Evaluation and Preparation

• Female ovarian reserve assessment (AMH, antral follicle count, hormone profile).
• Karyotype analysis for both partners to rule out structural abnormalities like balanced translocations.
• Collection of genetic report from the proband (affected relative); the Georgian lab may require repeat blood sampling for verification.
• Probe design or selection of an existing NGS panel to confirm coverage of the target mutation.
• Legal formalities: passport notarization, birth certificate translation, marriage certificate authentication (required by some centers).

Phase 2: Egg Retrieval and Embryo Culture

• Initiate ovarian stimulation (typically antagonist protocol; Gn dose adjusted based on age and AMH).
• IVF after egg retrieval (ICSI recommended to avoid sperm DNA contamination).
• Embryo culture to blastocyst stage on day 5-6.
• Biopsy: select blastocysts graded B or above; remove 5-6 trophectoderm cells per embryo.
• Immediate vitrification of blastocysts; biopsy cells sent to genetics lab.

Phase 3: Genetic Testing and Report

• Whole Genome Amplification (WGA) followed by NGS or aCGH.
• PGT-A results typically available within 1 week; PGT-M requires 2-4 weeks (including family validation).
• Report includes: chromosome ploidy, structural abnormalities, and monogenic mutation carrier status.

Phase 4: Transfer Preparation

• If a fresh cycle (no biopsy), transfer occurs within the cycle; however, PGT usually involves a frozen-thawed cycle.
• Endometrial preparation: natural cycle, hormone replacement, or stimulated cycle, chosen based on patient profile.
• Confirm embryo survival after thawing before transfer; transfer 1-2 healthy embryos.
• Luteal support until pregnancy test day.

Test Indicator Interpretation: Key Parameters

Special Situation: PGT with Egg/Sperm Donation

If eggs are from a donor known to carry a recessive pathogenic gene (e.g., cystic fibrosis), the recipient couple can opt for PGT-M on the resulting embryos. Georgian law allows specifying the testing purpose in the donation agreement, but donor anonymity must be maintained, and results used only for embryo selection, not disclosed to third parties. Similarly, if using donor sperm, carrier screening results can be requested, and PGT combined if necessary. Note: if the egg donor is older (e.g., ≥35 years), concurrent PGT-A to exclude aneuploidy is recommended.

Practitioner Observations: Common Issues for Overseas Patients

• Language Barrier: Georgian is the official language. Most reproductive centers have English or Russian translators, but Chinese translation resources are limited. Patients are advised to hire an independent interpreter or choose a center with a Chinese coordinator.
• Embryo Shipping: Some patients wish to ship embryos back to their home country after biopsy and genetic testing in Georgia. Georgian law allows embryo export, but requires export permits, liquid nitrogen tank transport contracts, and import permission from the destination country (only certain cities in China allow it). Currently, the process is complex, and most patients opt for transfer within Georgia.
• Legal Change Risk: In 2023, the Georgian Ministry of Health reviewed amendments to the Assisted Reproduction Law, potentially affecting surrogacy and PGT indications. Although not formally passed, future changes could impact PGT-M application conditions. It is advisable to confirm the current legal status one month before starting the cycle.

Suggested Timeline

From initial consultation to final transfer, the process typically takes 4-6 months.

• Months 1-2: Genetic counseling, family validation, probe design, legal document preparation.
• Month 3: Ovarian stimulation, egg retrieval, embryo biopsy, freezing.
• Months 4-5: Genetic testing, result interpretation, endometrial preparation.
• Month 6: Transfer, pregnancy test.

If probe design takes more than one month, the total time may extend to 7-8 months. Some centers allow early probe design and freezing of biopsy samples, but this incurs additional storage fees.

Risk Reminder

Preimplantation genetic diagnosis is not 100% accurate. Due to the limited number of biopsied cells (5-6), there is a risk of missed mosaicism or misdiagnosis, with a false-negative rate of about 1%-2%. For PGT-M, if the probe design does not cover key exons or if there is a de novo mutation, diagnosis may fail. Additionally, the biopsy procedure may slightly affect embryo developmental potential, and post-transfer prenatal diagnosis (chorionic villus sampling or amniocentesis) is recommended for confirmation. The regulatory system for reproductive centers in Georgia differs from that in China. Patients should verify that the center holds a valid Ministry of Health license and that its collaborating laboratory is CAP or ISO15189 accredited. Before signing a contract, request the center's live birth rate data for past PGT cycles (not success rate promises) and carefully read the clauses regarding testing limitations in the informed consent form.