How long does PGT testing take?

You've had your embryos biopsied, and now you're getting three different answers to what should be a simple question. One clinic says one to two weeks. Another says six to eight. Someone who did PGT-P says it took even longer.

These numbers aren't contradicting each other. They're counting different clocks.

And the families who get results in two weeks aren't getting the same answer faster. They're getting a narrower answer.

The timelines online are measuring different things

PGT-A checks whether an embryo has the right number of chromosomes. That's it. Most labs return results in about seven to ten business days after they receive the biopsy sample. So when a clinic says "one to two weeks," that's usually what they mean.

But that's lab turnaround, not the whole IVF timeline. If you're counting from stimulation through retrieval, embryo culture, biopsy, freezing, and results, the total IVF-with-PGT timeline is usually closer to six to eight weeks. That's where the bigger number comes from. And even that still leaves the frozen embryo transfer for later.

PGT-P is a different test. It screens for common diseases like type 2 diabetes, heart disease, and Alzheimer's by looking across thousands of genetic variants at once. That's a much harder question than chromosome counting.

So yes, it takes longer.

Where the extra time actually goes

Some of that time isn't testing at all. After retrieval, embryos grow in the lab for five or six days until they reach the blastocyst stage. Then an embryologist takes a small biopsy from the outer cell layer, the part that becomes the placenta, not the baby. The embryos are vitrified and stored while the biopsy samples ship to the lab.

For PGT-A, the lab mostly needs enough sequencing to count chromosomes. That's why it can come back fast.

For PGT-P through Herasight, we have to do something completely different. We sequence both parents at full genome depth, then use that plus the embryo biopsy to reconstruct each embryo's genome. From there we calculate within-family polygenic scores across multiple conditions and run mandatory carrier screening in the same report.

This is the difference between skimming a table of contents and reading the book. If you're trying to count chromosomes, the skim is enough. If you're trying to estimate risk for common diseases shaped by thousands of variants, it isn't.

Our standard turnaround is about eight weeks from sample receipt to report delivery. For families who need results faster, we also offer an urgent pathway that can bring that down to about four weeks.

And sometimes the timeline is shorter than people expect. If you've already done PGT-A at another clinic, you may already have the embryo data we need. Our ImputePGTA technology can extract polygenic risk scores from that existing data without a new embryo biopsy.

Why does that work at all? Because standard PGT-A still captures a thin layer of genomic signal. Not much. But enough, in some cases, to reconstruct what is missing when you combine it with high-quality parental sequencing. We demonstrated this in a study (preprint; peer review pending) that low-resolution PGT-A sequencing can be imputed up to full-genome resolution. For families who already have PGT-A data, that can save weeks and avoid another embryo procedure.

The wait isn't hurting your embryos

A common worry is that the longer timeline somehow damages the embryos.

It doesn't.

A study of 58,001 vitrified blastocysts over eleven years found no association between storage duration and clinical outcomes. A separate systematic review reached the same basic conclusion: prolonged storage did not significantly affect reproductive or neonatal outcomes.

That makes sense once you remember what vitrification is doing. At liquid nitrogen temperatures, biological activity is basically stopped. No degradation. No aging. No change anyone can measure. The embryo you transfer months later is not quietly getting older in storage.

So the real question isn't whether the extra weeks are costing you anything biologically. They aren't. It's whether you want to make a transfer decision with the best information available.

We have this strange situation in reproductive genetics right now where a lot of families are still choosing embryos mostly by how they look under a microscope.

Morphology grading is the default. It tells you how an embryo looks, not whether one embryo has materially higher genetic risk for diabetes or heart disease than another.

We can do better than that.

A few extra weeks can be the difference between choosing with chromosome counts and appearance alone, or choosing with a much deeper view of the embryo's genome.

If you want to understand what Herasight's screening timeline would look like for your situation, reach out to our team. We can walk you through the process and what to expect.