Use this calculator to estimate the chance of a live birth from an IVF embryo transfer based on age at egg retrieval, embryo day, PGT-A status, and how many embryos you transfer. It also shows how your chance can add up over 1 to 3 transfer attempts using clear, adjustable assumptions.
Advanced options
How to use our Embryo Transfer Success Predictor Calculator
- Enter your age at egg retrieval (the age when the eggs were collected or the embryo was created).
- Choose the transfer stage (Day 3 or Day 5 to 7). Day 5 to 7 is usually a blastocyst.
- Select the PGT-A status (not tested/unknown, tested but not confirmed euploid, or confirmed euploid).
- Enter how many embryos are transferred in one attempt (1 to 3).
- Pick how many transfer attempts you want to estimate (1, 2, or 3).
- Optional: Open Advanced options and choose a baseline rate source (this is the starting point the calculator uses).
- Optional: If you have a blastocyst grade (Gardner, like 4AA), enter it and turn grade adjustment On if you want a broad, simplified adjustment.
- Optional: Set the embryo independence assumption (0 to 100). Higher means the math treats each embryo/attempt more like a separate coin flip.
- Optional: Choose whether to show live birth only, or live birth plus clinical pregnancy.
- Click Calculate, then read the per-attempt results and the cumulative chance after your planned number of attempts.
Definitions
IVF (in vitro fertilization): A process where eggs are collected, fertilized in a lab, and an embryo is placed into the uterus.
Embryo transfer: The step in IVF where an embryo is placed into the uterus.
Transfer stage (Day 3 vs Day 5 to 7): Day 3 embryos are earlier. Day 5 to 7 embryos are usually blastocysts.
Blastocyst (Day 5 to 7): A later-stage embryo with a fluid cavity and different cell layers. [4]
PGT-A: Preimplantation genetic testing for aneuploidy, a lab test that checks embryo cells to estimate chromosome (DNA package) counts.
Euploid: An embryo with a typical number of chromosomes based on PGT-A results.
Embryo grade (Gardner): A blastocyst scoring system using an expansion number (1 to 6) plus two letters (A to C) that describe how the inner cell mass and outer cell layer look.
Clinical pregnancy: A pregnancy confirmed clinically (often by ultrasound). Definitions can vary by clinic.
Live birth: A birth outcome (the endpoint most people care about when comparing chances).
Cumulative chance: The chance of at least one success after more than one try.
Methodology
What this calculator is estimating
This tool estimates (1) the live birth chance per transfer attempt and (2) the chance of at least one live birth after 1 to 3 attempts. If you choose to also show clinical pregnancy, it will display an additional per-attempt estimate as a secondary output.
Step 1: Pick a baseline per-embryo chance
The calculator starts from a baseline probability for one embryo in one transfer attempt. The baseline depends on the baseline rate source you pick, plus your age at egg retrieval (grouped into age bands), the transfer stage (Day 3 vs Day 5 to 7), and your PGT-A status. The goal is transparency: you can see and change the baseline source instead of relying on a black box. CDC ART reporting is one common way people look at national context, but it is not a personalized forecast. [1]
Step 2: Optional grade adjustment (blastocyst only)
If you turn on grade adjustment and you entered a Gardner blastocyst grade (like 4AA), the calculator applies a broad multiplier to the baseline per-embryo chance. This is intentionally coarse because grading is subjective, grading categories vary by lab, and grade is only one piece of the picture. If you selected Day 3, any Gardner grade input is ignored (Gardner grading is for blastocysts).
Step 3: Combine multiple embryos transferred in one attempt
If you transfer more than one embryo in the same attempt, the calculator estimates the chance of at least one live birth from that attempt. It uses: p_at_least_one = 1 - (1 - p_single)^(n * dep_factor), where p_single is the (possibly adjusted) per-embryo probability, n is embryos transferred, and dep_factor equals your independence assumption divided by 100. If you set independence to 100%, this becomes the standard independent-events formula: 1 - (1 - p_single)^n.
Step 4: Combine multiple attempts (1 to 3)
To estimate cumulative chance after k attempts, it uses: p_cumulative = 1 - (1 - p_attempt)^k, where p_attempt is the per-attempt probability after combining embryos. This assumes the chance is the same each attempt. The independence setting is a user-controlled way to reduce overconfidence because outcomes from embryos made in the same cohort can be related (for example, shared egg quality). Evidence that outcomes can be correlated within a cohort is one reason the calculator does not force full independence. [2]
Clinical pregnancy output (optional)
If enabled, the clinical pregnancy estimate is computed the same way as live birth, but with a different baseline probability. Clinical pregnancy is shown as a secondary outcome because it is not the same as live birth.
Input validation and safety checks
The calculator blocks impossible or inconsistent inputs. Embryos transferred must be a whole number 1 to 3. Attempts must be 1 to 3. Independence must be 0 to 100. If you choose PGT-A confirmed euploid while selecting Day 3, the calculator shows an error and asks you to fix the stage or PGT-A status. If you choose a euploid-only research baseline, the calculator requires PGT-A status to be confirmed euploid.
Interpreting results and important limits
All percentages are averages across many similar cases, not a promise for any one person. The model does not account for important factors like uterus health, transfer technique, embryo thaw survival, donor eggs, medical conditions, or clinic-specific lab performance. If embryos transferred is greater than 1, the calculator shows a note that transferring more embryos can raise the chance of twins or more, which can raise pregnancy risks.