Herasight vs Orchid: how they differ

Imagine you went through IVF and had five healthy embryos. Now suppose there are only two embryo screening companies. How would you decide which one to use? 

Herasight and Orchid are both CAP-accredited and CLIA-certified, with labs in North Carolina. Both offer preimplantation genetic testing for polygenic conditions (PGT-P) with counseling included. MIT Technology Review named embryo scoring one of its 10 Breakthrough Technologies for 2026. On a spec sheet, these two companies look similar.

However, Herasight's polygenic scores are better on average across the diseases where both companies screen.Herasight also covers traits outside Orchid's standard panel, including cognitive ability and additional developmental-disorder risk scores. And if a family's clinic has already run PGT-A, Herasight can extract polygenic results from that existing biopsy. Orchid can't. That means you don't need to switch labs to have Herasight give you insight into polygenic diseases and traits. Instead, they can use the data from the PGT-A test, in conjunction with parental whole-genome sequencing, to infer the distinct genetic differences between each of your embryos. 

For Orchid, polygenic scoring is a product layered on top of their sequencing pipeline, and there's no statistical geneticist on the team. Herasight is built around polygenic prediction, with scores designed from the ground up for embryo screening. 

Predictor accuracy and trait coverage

For a family choosing between embryos, two things separate the companies: how accurate the score is on each disease the family cares about, and which diseases are in the catalog at all. 

On diseases for which both companies offer predictors, Herasight can explain more of the genetic variance underlying the disease than Orchid can.

The trait catalog itself is part of the comparison. Orchid's 12 standard diseases are Alzheimer's, atrial fibrillation, bipolar disorder, breast cancer, celiac disease, coronary artery disease, inflammatory bowel disease, prostate cancer, severe obesity, schizophrenia, type 1 diabetes, and type 2 diabetes. Herasight covers all of these, and more, including Cognitive ability screening (CogPGT) and ADHD. Herasight's NeuroRisk predictor quantifies the inherited rare-variant contribution to neurodevelopmental disorder risk, which Orchid doesn't address. Herasight's carrier screening also covers more monogenic conditions than Orchid's standard offering.

Consider a case: both parents carry significant genetic risk for type 2 diabetes, and have five chromosomally normal embryos after PGT-A. In families where both parents are affected, the absolute risk difference between the highest-risk and lowest-risk embryo can exceed 40%. 

A brief note on sibling validation: for most disease scores, performance within families and in the general population is statistically indistinguishable. Within-family validation becomes important for traits heavily shaped by family environment or population structure. Educational attainment is the canonical case. Moore et al. 2025 checked all 17 Herasight disease scores on sibling pairs and found no decrease for 16 of 17; osteoporosis was the one exception, with a modest attenuation. Orchid has published sibling-pair analysis for 7 conditions; of the 12 in their standard panel, 6 are covered, so Alzheimer's, schizophrenia, bipolar, celiac, and type 1 diabetes are not.

How each lab works 

Orchid does deep whole-genome sequencing on every embryo. One biopsy, one workflow, one report covering aneuploidy, single-gene conditions, and polygenic scoring. The sequencing itself is strong for monogenic detection and for catching large structural variants.

Herasight's workflow is different on purpose. Parents get 30x whole-genome sequencing using both short and long reads. Embryos get 2x low-pass sequencing to test for aneuploidy. The parental data is then used in conjunction with 2x sequencing to reconstruct the embryo genomes at higher effective resolution than per-embryo sequencing typically provides. This trio approach is more accurate for polygenic prediction because embryo DNA samples are small and noisy, while parental samples are clean and plentiful.

Herasight also runs aneuploidy, monogenic, and polygenic screening in a single workflow. That isn't an Orchid-only capability. And Herasight's aneuploidy screening runs at roughly ten times the coverage depth Orchid uses.

The one thing per-embryo deep sequencing does better is detect de novo mutations that appear in the embryo but not in either parent. That's a narrow clinical need. For families who want it, Herasight offers a higher-coverage sequencing add-on (~40x) on a single embryo after the initial screen narrows down candidates. Running it on every embryo is expensive and almost always unnecessary.

There's also a Herasight capability with no Orchid equivalent. If your clinic has already run PGT-A on your embryos, Herasight's ImputePGTA reconstruction can pull polygenic risk scores from that existing PGT-A data plus parental sequencing. No new embryo biopsy required. 

Ancestry coverage

For non-European families, ancestry is often the first thing that narrows the field.

Orchid publishes its own ancestry table. Families of European descent receive all 12 polygenic reports. South Asian families receive 10. East Asian families receive 9. Families of African descent receive 2. Orchid delivers a report for a given disease only when the score's accuracy clears a strict threshold for that ancestry, and for most diseases and most non-European ancestries, that threshold isn't met.

This is a field-wide problem, not specific to Orchid. Most polygenic scores were built from datasets that skew heavily European, and scores trained primarily on European data perform substantially worse for other populations. It's been one of the biggest limitations of polygenic screening from the beginning.

Herasight calibrates and validates scores across 8+ ancestry groups. Moore et al. 2025 uses methods including SBayesRC, a newer statistical approach that uses functional genomic annotations to improve how well scores transfer between populations. For a non-European family, the comparison often narrows to whether Orchid can deliver anything useful at all. For a family of African descent, the gap between 2 conditions and Herasight's full trait catalog is the whole comparison.

If your main concern is a specific single-gene condition, both companies can screen for it alongside aneuploidy and polygenic scoring in the same workflow. If your concern is polygenic accuracy and trait coverage, Herasight is ahead on average across the shared catalog and covers conditions Orchid doesn't. If you're a non-European family, check the trait-by-ancestry list before anything else. That's often where the real comparison ends.

Both companies are transparent with their customers and offer scientifically validated predictors. The power of the predictors the companies use is where they come apart.

If you want to see what the numbers look like for your specific family situation, try the calculator. If you have questions about what this comparison means for you, reach out.

Herasight does not provide medical diagnoses or tell patients which embryo to transfer. Polygenic risk scores are probability estimates, not guarantees. The decision of which embryo to transfer is between you and your clinician.