Yes. Select the age band of the egg provider (donor) rather than the recipient. Chromosomal competence is determined by the egg source, not by the uterus or gestational carrier.
IVF Genetic Testing Tool
PGT-A Euploid Probability Calculator
Estimate the probability that your embryos are euploid (chromosomally normal) based on age, blastocyst day, and morphology grade.
PGT-A Euploid Probability Calculator
Estimate euploid probability using age, blastocyst day, and morphology.
#1
Euploid probability:50.0%
Probability of ≥1 Euploid
50.0%
Based on 1 embryo(s)
Expected Euploid Count
0.5
Sum of individual probabilities
Per-Embryo Summary
#1: D5, BB50.0%
Disclaimer: Educational estimate only. Values are capped to reflect biological uncertainty.
How This Calculator Works
This calculator estimates the likelihood that an embryo is chromosomally normal (euploid) using three main factors derived from large PGT-A datasets:
- Age at Egg Retrieval: Euploidy rates decline with age — about 68% for ≤30 years, 58% for ages 31–34, 50% for 35–37, 35% for 38–40, 22% for 41–42, and 16% for ≥43.
- Blastocyst Development Day: Embryos that reach blastocyst earlier tend to be more chromosomally normal. Day 5 ×1.00, Day 6 ×0.80, Day 7 ×0.50.
- Morphology Grade: Embryos with stronger ICM and TE quality have higher euploid chances. AA ×1.15, AB/BA ×1.10, BB ×1.00, BC/CB ×0.75, CC ×0.55.
Calculation Formula:
Euploid Probability = Age Baseline × Day Multiplier × Morphology Multiplier
Results constrained between 5%–85%, with total probability capped at 99%.
Understanding Your Results
- Expected Euploid Count (∑pᵢ): Shows the average number of embryos likely to be chromosomally normal. Example: If six embryos are entered and the total is 3.2, about three may be euploid.
- Probability of ≥1 Euploid Embryo: Reflects the likelihood that at least one embryo in your set is chromosomally normal. Even with multiple embryos, this probability is capped at 99% to avoid implying absolute certainty.
- Per-Embryo Probability: Each embryo's result depends on its age band, development day, and morphology combination. Day 5 AA embryos in younger age bands show the highest predicted probabilities.
Important Note on Variability: While the model is based on large PGT-A datasets, these estimates are meant for educational reference only. Each individual's biology, lab conditions, and clinical context may differ, resulting in natural variability beyond statistical prediction.
Next Step: PGT-A testing identifies which embryos are chromosomally normal, but the next question is: What is the chance of achieving a live birth? Use our Embryo Transfer Success Rate Calculator to estimate your expected live birth probability per transfer. Embryo Transfer Success Rate Calculator.
Scientific Basis
The PGT-A Euploid Probability Calculator is built upon decades of reproductive genetics research and thousands of tested embryos across U.S. fertility centers. It reflects how three biological mechanisms—maternal age, embryo developmental timing, and morphological quality—interact to determine chromosomal normality.
1. Age and Meiotic Error
As maternal age increases, the quality of oocytes declines due to cumulative damage in the meiotic spindle and mitochondrial function. Chromosome-segregation errors during meiosis I become more frequent, leading to higher rates of aneuploid embryos.
In women under 30, about two-thirds of embryos are chromosomally normal; by 40, that number drops to roughly one-third, and by 43 and beyond, to less than one in five. This age-related decline forms the baseline of the model.
2. Blastocyst Day and Developmental Speed
Embryos that reach the blastocyst stage earlier (Day 5) usually have stronger metabolic efficiency, better genomic activation, and lower cellular stress. Delayed development (Day 6 or 7) may indicate chromosomal imbalance or suboptimal cellular energy, resulting in a reduced chance of being euploid.
Studies consistently show a stepwise decline in euploid rates from D5 → D6 → D7.
3. Morphology and Cell Line Quality
Blastocyst morphology grading—based on the quality of the inner cell mass (ICM) and trophectoderm (TE)—is a visual proxy for cellular organization and genome stability. Embryos with compact ICM and cohesive TE layers (grades AA–AB–BA) demonstrate lower DNA-damage rates and better chromosomal integrity.
Conversely, embryos with loose or sparse TE (BC, CC) tend to show more fragmentation and abnormal division patterns.
Together, these three predictors explain most of the variation observed in chromosomal outcomes after IVF and form the foundation of the calculator's probability model.
For Surrogates
Understanding PGT-A helps you know what type of embryos are being transferred.
Euploid embryos have higher implantation and live birth rates, which means a smoother pregnancy journey for you. Your IVF clinic will always ensure the embryo transferred meets the highest quality standards.
For Intended Parents
Use this calculator to understand your embryo bank.
PGT-A testing helps select the best embryos for transfer to your gestational carrier, maximizing your chances of a successful pregnancy and healthy baby.
Tip: Combine this with the Embryo Transfer Calculator for complete transfer planning. Embryo Transfer Calculator
PGT-A: Frequently Asked Questions
1. Is this PGT-A Euploid Probability Calculator suitable for donor-egg cycles?
2. What do D5, D6, and D7 mean in embryo development?
These indicate the day an embryo reached the blastocyst stage after fertilization. Embryos that form blastocysts earlier (Day 5) generally have higher euploid probability, while Day 6 and Day 7 embryos often show slower development and slightly lower chromosomal stability.
3. How does embryo morphology (AA–CC) influence euploid probability?
Morphology grading evaluates the inner cell mass (ICM) and trophectoderm (TE) quality. High-quality embryos (AA, AB, BA) have more organized cellular structure and greater genome stability, whereas lower grades (BC, CC) are more prone to fragmentation—hence, lower euploid probability.
4. Does a high PGT-A euploid probability guarantee pregnancy success?
No. A euploid embryo has the correct number of chromosomes, but implantation and live-birth outcomes depend on additional factors such as uterine environment, hormonal balance, embryo transfer technique, and overall maternal health.
5. Why does the calculator cap probabilities at 85% and 99%?
To reflect biological variability and laboratory uncertainty. Even when conditions are optimal, real-world data show that no scenario can offer absolute certainty—so probabilities are capped for scientific realism.
6. When will I receive my PGT-A results after embryo biopsy?
Most genetics laboratories provide results within 10 to 14 days after biopsy. Turnaround time may vary slightly between IVF clinics, testing platforms, and workflow schedules.
7. How reliable is this calculator for individual IVF cases?
This model is based on large multicenter datasets and validated research, but it provides an educational estimate only. Individual outcomes can vary due to differences in ovarian response, egg quality, lab conditions, and biopsy methods. Use it as a guide—not a guarantee.
References
- Morris J, Brezina P, Kearns W. The rate of aneuploidy and chance of having at least one euploid tested embryo per IVF cycle in 21,493 PGT-A tested embryos. Fertility and Sterility. 2021;116(1 Suppl):E15. [Link]
- Mouhanna J, Rodriguez S, Ibrahim MH, et al. Embryo grading: is it a good predictor for euploidy? Fertility and Sterility. 2024;122(4 Suppl):E325. [Link]
- Barash OO, Ivani KA, Willman SP, et al. Blastocysts available for biopsy on day 5 are more likely to result in a viable pregnancy. Fertility and Sterility. 2014;102(1 Suppl):E62. [Link]
- Chen X, Fan Y, Ji H, et al. Effect of blastocyst morphology and developmental rate on euploidy and live birth rates in PGT-A cycles. Reproductive Sciences. 2025;32:1705–1712. [Link]
- Ibrahim MH, Attia GR, Wang H, Patrizio P. Low DNA and inconclusive results after PGT-A: relationship with day of biopsy (day 5 vs day 6) and embryo quality. Fertility and Sterility. 2023;120(4 Suppl):E275. [Link]
🔬 Explore More Pregnancy Tools
Discover our free, medically informed calculators to plan your IVF and pregnancy journey.
You are here
PGT-A Euploid Probability Calculator
Estimate euploid probability using age, blastocyst day, and morphology.
Embryo Transfer Success Rate Calculator
Estimate live birth rate for PGT-A euploid single-embryo transfers.
Due Date Calculator
Calculate your estimated due date from LMP or IVF transfer.
Pregnancy Weight Gain Calculator
Estimates healthy weight gain based on Institute of Medicine guidelines.
BMI Calculator
Check if your BMI meets surrogacy eligibility requirements.
Height & Weight Converter
Convert between metric and imperial units. Type in any field—we'll auto-convert the rest.
Ready to Begin Your Surrogacy Journey?
Whether you're looking to become a surrogate or start your family through surrogacy, we're here to guide you every step of the way.
This calculator provides educational estimates only and should not be considered medical advice. Results may vary based on individual circumstances. Always consult with your healthcare provider for personalized medical guidance.