Can Shanghai Renji Hospital Perform Embryo Genetic Testing? PGT Indications and Process Explained
The Reproductive Medicine Center of Shanghai Renji Hospital is qualified to perform Preimplantation Genetic Testing (PGT), including chromosome aneuploidy screening, single-gene disease testing, and chromosomal structural rearrangement testing. This article explains the PGT candidate population, testing process, timeline, cost reference, and key considerations at Renji Hospital, helping patients objectively understand this technology.
Opening: Real consultation scenario
"Doctor, I've had two miscarriages before. Chromosome tests showed I am a carrier of a balanced translocation. I heard Renji Hospital can perform embryo genetic testing. Is my situation suitable for this?" — 35 years old, recurrent miscarriage, carrier of balanced chromosome translocation
This is a real question raised at the genetic counseling clinic of Renji Hospital. Embryo genetic testing, in the field of reproductive medicine, corresponds to Preimplantation Genetic Testing (PGT), commonly known as "third-generation IVF." The Reproductive Medicine Center of Shanghai Renji Hospital is one of the first centers in China to obtain PGT qualification, possessing the technical capability and clinical experience to perform chromosome aneuploidy screening, single-gene disease testing, and chromosomal structural rearrangement testing.
Can Renji Hospital Perform Embryo Genetic Testing?
Yes. The Reproductive Medicine Center of Shanghai Renji Hospital routinely performs Preimplantation Genetic Testing (PGT), specifically including the following three types:
- PGT-A (Aneuploidy Screening): Detects numerical chromosome abnormalities in embryos, suitable for groups such as advanced maternal age, recurrent miscarriage, and recurrent implantation failure.
- PGT-M (Monogenic Disease Testing): Targets single-gene genetic disorders with known pathogenic genes, such as thalassemia, spinal muscular atrophy (SMA), and hereditary hearing loss.
- PGT-SR (Structural Rearrangement Testing): Used for carriers of chromosomal structural abnormalities like balanced translocations, Robertsonian translocations, and inversions, to select embryos with normal chromosomal structure.
Renji Hospital is also the location of the Shanghai Genetic Disease Diagnosis Center, with close integration of genetic counseling, genetic testing, and reproductive medicine, providing a complete clinical pathway for PGT.
From a Clinical Perspective: PGT is Not Always Necessary
As reproductive doctors, we often encounter two extremes in daily clinics: one group considers PGT a "universal insurance," while the other is completely unaware of this technology. Objectively, PGT has clear application boundaries.
Conditions suitable for PGT:
- Female age ≥ 38 years (significantly increased risk of aneuploidy);
- One or both partners are carriers of chromosomal structural abnormalities (balanced translocation, Robertsonian translocation, inversion, etc.);
- History of ≥ 2 spontaneous miscarriages with confirmed chromosomal abnormalities in the products of conception;
- Both partners carry pathogenic genes for the same or different single-gene genetic disorders;
- Recurrent implantation failure (≥ 3 transfers of good quality embryos without pregnancy);
- Severe male factor infertility (e.g., non-obstructive azoospermia, possibly involving chromosomal microdeletions).
Conditions unsuitable or not routinely requiring PGT:
- Young couples (< 35 years) with no adverse pregnancy history or family history of genetic diseases; PGT-A offers limited benefit;
- Severely diminished ovarian reserve (AMH < 0.5 ng/mL) with very few eggs retrieved; biopsy may result in no usable embryos;
- Only mild male oligoasthenospermia without genetic indications;
- Polygenic diseases that PGT technology cannot detect (e.g., most psychiatric disorders, diabetes).
When deciding whether to use PGT, doctors comprehensively evaluate the patient's reproductive history, genetic risk, ovarian function, number of embryos, and the limitations of the technology itself. PGT does not improve embryo implantation rates nor guarantee a completely healthy baby—it only screens for specific genetic issues.
Differences Between Renji Hospital and Other Hospitals in PGT
Several reproductive centers in Shanghai have PGT qualifications, but Renji Hospital has the following notable characteristics:
| Dimension | Renji Hospital Features |
|---|---|
| Genetic Support | On-site Shanghai Genetic Disease Diagnosis Center integrates genetic counseling, genetic testing, and prenatal diagnosis, ensuring smooth coordination for post-PGT prenatal diagnostic verification. |
| Testing Platform | Uses NGS (Next-Generation Sequencing) + SNP array platform, simultaneously detecting chromosomal copy number variations and single-gene mutations, with resolution exceeding clinical standards. |
| Embryo Biopsy | Laser-assisted trophectoderm biopsy of blastocysts, followed by vitrification cryopreservation; freeze-thaw survival rate is stable above 95%. |
| Multidisciplinary Collaboration | Joint clinics involving Reproductive Medicine, Genetics, Prenatal Diagnosis Center, and Reproductive Endocrinology, enabling one-stop evaluation for complex cases. |
| Clinical Data Accumulation | Among the highest number of PGT cycles in Shanghai, with a substantial database particularly in chromosome translocation and single-gene disease testing. |
PGT processes, testing platforms, cost structures, and cycle lengths vary between hospitals. When choosing, it is recommended to focus on the hospital's genetic counseling capabilities and laboratory quality control system, rather than just the technology name.
Complete PGT Process at Renji Hospital
From the initial genetic counseling to completing the transfer, the PGT pathway at Renji Hospital is divided into the following stages:
Stage 1: Genetic Counseling and Evaluation
- Both partners attend the consultation together, bringing previous chromosome reports, genetic reports, and results from miscarriage tissue testing (if available);
- A reproductive geneticist evaluates the indications and determines the type of testing (PGT-A / PGT-M / PGT-SR);
- If PGT-M is needed, family segregation studies must be completed first to confirm the pathogenic gene locus, a process taking about 1-2 months;
- Sign informed consent, explaining the scope, limitations of testing, and disposition plan for remaining embryos.
Stage 2: Ovarian Stimulation and Egg Retrieval
- Individualized stimulation protocol based on female age, AMH, and antral follicle count;
- Egg retrieval performed in the operating room at Renji East Hospital under intravenous sedation;
- ICSI fertilization is routinely performed after retrieval to avoid polyspermy interfering with test results.
Stage 3: Embryo Culture and Biopsy
- Embryos are cultured in sequential media to the blastocyst stage on day 5-6;
- For blastocysts meeting biopsy criteria (generally inner cell mass and trophectoderm grade ≥ BC), a hole is made in the zona pellucida, and 3-5 trophectoderm cells are aspirated;
- After biopsy, the blastocyst is immediately vitrified and frozen, awaiting test results.
Stage 4: Genetic Testing and Result Interpretation
- Biopsied cells undergo whole genome amplification, followed by machine testing (NGS or SNP array);
- PGT-A results take about 2-3 weeks; PGT-M and PGT-SR take about 4-6 weeks (including comparison with family segregation data);
- The test report includes: embryo chromosomal copy number, target gene mutation status, and whether the chromosomal structure is balanced.
Stage 5: Frozen Embryo Transfer
- Select embryos that are chromosomally normal/balanced and do not carry the target pathogenic gene;
- Prepare the endometrium in a natural cycle or hormone replacement cycle, and schedule the transfer;
- Pregnancy test 12-14 days after transfer; if pregnancy is confirmed, prenatal diagnosis (amniocentesis) is recommended for verification.
Timeline: How Long from Start to Transfer
| Stage | Approximate Duration | Key Variables |
|---|---|---|
| Genetic Counseling + Family Segregation (if needed) | 1-2 months | Whether a clear genetic diagnosis already exists; family members' cooperation with sampling |
| Ovarian Stimulation + Egg Retrieval | 2-3 weeks | Ovarian response, choice of stimulation protocol |
| Embryo Culture + Biopsy | 5-7 days | Embryo development speed, blastocyst formation rate |
| Genetic Testing | 2-6 weeks | Type of test (PGT-A fastest, PGT-M slowest) |
| Frozen Embryo Transfer | 1-2 months | Endometrial preparation protocol, menstrual cycle scheduling |
| Total Cycle (from first visit to transfer) | Approximately 4-8 months | Main waiting time is during family segregation and testing stages |
If the couple already has complete genetic diagnosis reports and karyotype analysis results, and ovarian function is normal, the total cycle can be shortened to 3-4 months. For older women or those with diminished ovarian reserve, multiple stimulation cycles may be needed to accumulate embryos, extending the time accordingly.
Cost Composition and Influencing Factors
PGT-related costs at Renji Hospital consist of the following parts, varying significantly between patients due to test type and number of embryos:
- Genetic Counseling and Family Segregation: Approximately 3,000-8,000 RMB (if sequencing verification of the proband and parents is needed);
- Ovarian Stimulation Medication and Egg Retrieval Surgery: Approximately 15,000-35,000 RMB (depending on the protocol and dosage);
- ICSI Fertilization and Embryo Culture: Approximately 8,000-12,000 RMB;
- Embryo Biopsy + Genetic Testing (charged per embryo): PGT-A about 3,000-5,000 RMB/embryo, PGT-M about 5,000-8,000 RMB/embryo, PGT-SR about 4,500-6,500 RMB/embryo;
- Frozen Embryo Storage: Approximately 1,200-1,800 RMB/year;
- Frozen Embryo Transfer: Approximately 8,000-15,000 RMB (including endometrial preparation medication and transfer procedure).
The total cost for a complete PGT cycle (excluding multiple stimulations) is roughly between 60,000 and 120,000 RMB. Shanghai has included some assisted reproductive items in medical insurance, but PGT-related genetic testing costs are currently out-of-pocket. It is recommended to confirm the latest reimbursement policy at the Renji Hospital insurance office before starting.
Five Most Easily Overlooked Details
- Prenatal diagnosis is mandatory after PGT: Embryo testing is a screening tool and cannot exclude all abnormalities. After pregnancy, amniocentesis for karyotype verification is recommended, especially for PGT-M and PGT-SR.
- Biopsied embryos may be mosaic: About 2-5% of embryos are chromosomal mosaics, where normal and abnormal cells coexist. The decision to transfer such embryos requires joint evaluation by a geneticist and reproductive doctor based on the mosaic ratio and type.
- Not all embryos are suitable for biopsy: Slow-developing embryos (not yet blastocysts on day 6) or those with poor inner cell mass quality may have their subsequent development affected by biopsy. Doctors may recommend direct transfer without biopsy or discarding.
- Genetic counseling requires both partners to be present: PGT-M testing requires blood samples from both partners and the proband (affected child or both parents). Absence of either party will prolong the family segregation time.
- The biopsy window for frozen embryos is limited: Once an embryo is frozen, the technical difficulty and risk of thawing and biopsying it are higher than for fresh blastocyst biopsy. Renji Hospital uniformly uses fresh blastocyst biopsy followed by freezing; therefore, after egg retrieval, embryos must be cultured in the laboratory until day 5-6 for biopsy, which cannot be done earlier or later.
Special Situations and Management Strategies
Situation 1: Diminished Ovarian Reserve, Few Eggs Retrieved (< 5)
Few eggs mean the number of blastocysts available for biopsy may be 0-2. Renji Hospital's strategy is: proceed with one stimulation cycle. If at least one biopsiable blastocyst forms, perform PGT; if no blastocyst forms, pause the PGT plan and consider conventional IVF or re-evaluate ovarian function. High-dose stimulation protocols to increase embryo numbers are not recommended, as they do not increase live birth rates.
Situation 2: Balanced Translocation Carrier, Recurrent Miscarriage
PGT-SR is an effective method for balanced translocation carriers to avoid recurrent miscarriage. Data from Renji Hospital shows that after PGT-SR screening, the clinical pregnancy rate per transfer for balanced translocation carriers is about 55-65%, and the miscarriage rate drops below 10%. However, patients must accept that approximately 1/3 to 1/2 of embryos will be chromosomally normal or balanced, potentially requiring multiple stimulation cycles to accumulate enough embryos.
Situation 3: Single-Gene Disease Testing, but Pathogenic Gene Not Yet Identified
In some families with genetic diseases, the clinical diagnosis is clear, but genetic testing has not found a known pathogenic locus. In such cases, the genetics department at Renji Hospital recommends first performing whole exome sequencing (WES) or whole genome sequencing (WGS) to search for candidate genes. Once pathogenicity is confirmed, PGT-M can be initiated. The entire process takes about 3-6 months.
Frequently Asked Questions
- Q: What is the accuracy of PGT testing at Renji Hospital?
A: PGT-A has a sensitivity >95% and specificity >98% for chromosome aneuploidy. The accuracy of PGT-M depends on the completeness of family segregation; with a clear pathogenic locus and thorough verification, accuracy can reach 97-99%. All PGT results require final confirmation through prenatal diagnosis. - Q: Is the success rate of third-generation IVF higher than second-generation IVF?
A: For couples with clear genetic indications, PGT can reduce miscarriage rates and the risk of transmitting genetic diseases, but it does not improve the implantation rate per single transfer. For young patients without genetic indications, PGT-A does not improve live birth rates and may reduce embryo utilization potential due to biopsy damage. - Q: Is there a waiting list for PGT at Renji Hospital?
A: Genetic counseling appointments need to be booked in advance, with a typical wait of 1-2 weeks. Once in the cycle, there is no waiting; ovarian stimulation is scheduled according to the menstrual cycle. Family segregation time depends on the testing center's schedule, usually taking 4-6 weeks for results. - Q: Can out-of-town patients come to Renji for PGT?
A: Yes. The Renji Hospital Reproductive Center accepts patients from all over the country. It is recommended to complete all genetic counseling and family segregation before starting stimulation to reduce travel. The stimulation and egg retrieval phase requires staying in Shanghai for about 2-3 weeks.
Interpretation of Key Examination Indicators
| Indicator | Reference Range (General) | Impact on PGT Decision |
|---|---|---|
| AMH | 1.0-4.0 ng/mL | AMH < 0.5 ng/mL indicates severely diminished ovarian reserve, possibly ≤ 3 eggs retrieved; need to assess whether PGT is worthwhile |
| FSH | < 10 IU/L | FSH > 12 IU/L suggests decreased ovarian response, requiring higher medication doses and potentially fewer eggs |
| Antral Follicle Count (AFC) | 5-20 | AFC < 5 indicates low ovarian reserve, increasing the cancellation rate of PGT cycles |
| Karyotype Analysis | 46,XX / 46,XY | Abnormal karyotypes (e.g., balanced translocation, Robertsonian translocation) are direct indications for PGT-SR |
| Carrier Screening (Expanded) | Negative | If both partners carry the same pathogenic gene, PGT-M is needed; if only one partner carries it, embryo health is usually unaffected |
The above indicators need to be interpreted comprehensively in conjunction with age and reproductive history. A single abnormal value does not mandate or prohibit PGT; a thorough evaluation by a reproductive geneticist is required.
Risk Reminder
Embryo genetic testing (PGT) is an auxiliary screening technology, not a treatment. The testing process carries possibilities such as embryo biopsy damage, misdiagnosis of mosaicism, and having no embryos available for transfer. PGT cannot detect all genetic diseases, especially polygenic disorders and de novo mutations. All PGT pregnancies are recommended to undergo amniocentesis for prenatal diagnosis at 18-22 weeks of gestation to confirm the fetal chromosome and genetic status.
The genetic counseling clinic at Renji Hospital is open Monday to Friday. For a first visit, you can make an appointment through the official WeChat public account of "Shanghai Renji Hospital" for the "Reproductive Medicine - Genetic Counseling" specialty clinic. It is recommended to bring all previous test reports and family history information, and for both partners to attend together.
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