Assisted hatching (AH) is a lab step where an embryologist makes a tiny opening in the embryo’s outer shell (zona pellucida) before transfer, to help it hatch and implant. The honest answer is that it is not a proven win for everyone: a 2021 Cochrane review of 39 randomized trials found a small rise in clinical pregnancy (OR 1.20) but no clear improvement in live birth, and a higher multiple-pregnancy rate (OR 1.38).
Data in this article comes from the Cochrane Database of Systematic Reviews, ASRM patient education materials, and peer-reviewed literature, compiled by the ProIVF Medical Editorial Team and reviewed by the ProIVF Medical Advisory Board.
What Is Assisted Hatching and Why Is It Done?
Every embryo grows inside a glycoprotein shell called the zona pellucida, and in natural conception it must break out of that shell before it can attach to the uterine lining. In IVF the embryologist sometimes makes a small crack or hole in this shell before transfer, hoping to make hatching and implantation easier.
For the full treatment sequence, see our IVF procedure guide.
Assisted hatching is not performed in every IVF cycle. It is offered selectively, for situations that can make natural hatching harder — an older egg often has a thicker zona, and a frozen embryo’s shell can change during cryopreservation.
How Do the Three Techniques Compare?
| Technique | How it works | Notes |
|---|---|---|
| Laser | A focused laser pulse melts a small hole in the shell | The most common method today; precise and fast |
| Chemical (Tyrode’s solution) | An acidic solution dissolves a small area of the shell | Older method, used less often now |
| Mechanical | A fine microneedle physically opens the shell | Rarely used; largely historical |
The embryologist works under a microscope, typically on day 3 (cleavage stage) or later at the blastocyst stage. It adds only a few minutes of lab work and does not change your medication plan.
Does Assisted Hatching Improve IVF Success Rates?
The best evidence is the Cochrane review updated in March 2021, which pooled 39 randomized controlled trials involving 7,249 women. Because study quality ranged from very low to low, the authors were cautious about every conclusion.
Key Results From the 2021 Cochrane Review
In this table, OR is the odds ratio comparing the assisted-hatching group to the control group (above 1 favors AH, below 1 against), and CI is the confidence interval.
| Outcome | Effect of assisted hatching | Evidence quality |
|---|---|---|
| Live birth rate | OR 1.09 (95% CI 0.92–1.29) — uncertain, no clear benefit | Low |
| Clinical pregnancy rate (all 39 trials) | OR 1.20 (95% CI 1.09–1.33) — possible small improvement | Low |
| Multiple pregnancy rate | OR 1.38 (95% CI 1.13–1.68) — likely increased | Low |
| Miscarriage rate | OR 1.13 (95% CI 0.82–1.56) — uncertain | Very low |
A clinical pregnancy is one confirmed on ultrasound; a live birth counts a baby born alive. The distinction matters because a treatment can move the two measures in different directions.
In plain terms, if the live birth rate without AH is about 28%, the rate with AH falls somewhere between 27% and 34% — and the confidence interval includes no benefit at all. For multiples, a baseline of about 9% rises to roughly 10–14%.
“Assisted hatching may slightly improve clinical pregnancy rates, but there is no clear evidence that it improves live birth, and it was associated with higher monozygotic twinning and multiple pregnancy.” — Cochrane systematic review of 39 randomized trials, Nyborg et al., 2021
Practically, AH should be a selective tool you discuss with your fertility specialist, not an automatic add-on.
Who May Benefit From Assisted Hatching?
The ASRM patient education materials list specific situations where AH may help, on the reasoning that these embryos are more likely to struggle to hatch naturally:
- Previous failed IVF cycles — especially two or more transfers of good-quality embryos that did not implant
- Advanced maternal age (typically 38 or older), where the zona pellucida is often thicker
- Frozen embryo transfers — the shell can harden or change during freezing and thawing (see our frozen embryo transfer guide)
- Embryos with a thickened or abnormally shaped zona pellucida
- PGT embryo biopsy — AH creates the opening used to remove cells for genetic testing
If you do not fall into one of these groups, the evidence does not suggest AH will meaningfully change your outcome. To see what actually drives IVF results, read our IVF success rate guide. A clinic should be able to explain its own criteria and data rather than selling AH as a standard “upgrade.”
Does Assisted Hatching Carry Risks?
The main risks come from physically handling the embryo and from how the opening affects embryo splitting.
- Embryo damage: Rarely the procedure damages the embryo enough to make it unusable; experienced labs report damage rates below 1%, though never zero.
- Identical (monozygotic) twins: Opening the shell slightly raises the chance the inner cell mass splits. A 2019 meta-analysis in Fertility and Sterility of 16 studies found an increased monozygotic twinning risk after AH (OR 1.17, 95% CI 1.09–1.27), and identical twin pregnancies carry higher rates of preterm birth and complications than singletons.
These risks are modest but real — which is why Cochrane’s caution about routine use matters.
How Does Assisted Hatching Relate to PGT?
If you are planning preimplantation genetic testing (PGT), AH is often done on day 3 so that a few trophectoderm cells can be removed for biopsy around day 5 or 6. In that context AH is a technical prerequisite for the biopsy, not an implantation aid, and the fee is usually bundled into the genetic-testing package.
Ask your clinic whether the step is being done for biopsy, for implantation, or both. For the testing options themselves, see our PGT-A, PGT-M and PGT-SR guide.
How Much Does Assisted Hatching Cost?
Assisted hatching is typically an add-on fee on top of the main IVF cycle, not a standalone treatment, with U.S. fees generally between $300 and $800 per cycle depending on the clinic. Some clinics bundle it into the embryology lab fee, so check your itemized quote before agreeing.
Because routine-benefit evidence is limited, cost is really a value question: know what your clinic charges, why it recommends AH for your situation, and what data supports that advice.
What Do Patients Say?
The following patient stories are shared with consent; names and identifying details have been changed to protect privacy.
Mei, 39, Los Angeles — elective use after two failed transfers. “After two cycles with good-quality embryos that just didn’t stick, my doctor suggested assisted hatching plus a frozen transfer. We paid $450 extra. The third transfer worked, and I can’t tell how much was the hatching and how much was luck, but I don’t regret trying it.”
Sarah, 34, New York — AH as part of PGT biopsy. “We were doing genetic testing, so the lab opened the shell for the biopsy anyway. It cost nothing extra because it was part of the PGT package. My clinic was clear it was for the biopsy, not implantation. I appreciated that honesty.”
Priya, 41, Houston — a cautious approach. “At 41 my clinic recommended AH because of my age and quoted $600. When I asked about the twin risk they explained the identical-twin increase was small but real. We did it and transferred one embryo. It didn’t work that cycle, but I knew exactly what I was signing up for.”
FAQ
Q: Is assisted hatching painful?
No — assisted hatching is performed in the laboratory on the embryo before transfer, so it involves no procedure on your body and you feel nothing: 0 physical steps are added to your cycle.
Q: Does assisted hatching guarantee implantation?
No: it may nudge clinical pregnancy up in some groups (OR 1.20), but for live birth the 2021 Cochrane review found no clear improvement — the confidence interval of 0.92–1.29 is consistent with a small benefit, no effect, or a small harm.
Evidence quality was low, so AH guarantees nothing.
Q: When is assisted hatching performed?
Usually on day 3 of embryo development (cleavage stage), or at the blastocyst stage on day 5–6 before transfer. For PGT the opening is typically made on day 3 so cells can be biopsied later; the exact timing is set by the lab.
Q: Does assisted hatching increase the risk of twins?
It slightly raises identical (monozygotic) twinning — the 2019 meta-analysis found OR 1.17 (95% CI 1.09–1.27). The absolute increase is small, but identical twin pregnancies carry higher complication risk than singletons.
Q: Does assisted hatching increase the risk of miscarriage?
The 2021 Cochrane review estimated a miscarriage odds ratio of 1.13 (95% CI 0.82–1.56). Because that interval includes 1, the data do not show a statistically significant increase, and the evidence quality was very low.
Q: Is assisted hatching covered by insurance?
The $300–$800 assisted hatching fee is rarely billed separately: most U.S. plans treat it as part of the IVF laboratory fee rather than a separately covered item, so ask for an itemized quote if you pay out of pocket.
Q: Is assisted hatching safe for frozen embryos?
Yes. It is commonly offered for frozen embryo transfers because the shell can harden during cryopreservation.
The procedure is the same, and the small risks (embryo damage below 1%, and identical twinning) still apply.
How Do You Decide Whether Assisted Hatching Is Right for You?
- Ask what evidence your clinic uses. A good clinic shares its own live-birth data with and without AH, not just “it helps implantation.”
- Confirm the reason for the recommendation. Age, repeated implantation failure, frozen transfer, or PGT biopsy — the reason changes how much AH matters.
- Get the fee in writing. Whether AH is bundled or billed separately (typically $300–$800 in the U.S.).
- Weigh the twin trade-off. If you strongly want to avoid twins, discuss whether the small identical-twin increase changes the decision.
You can compare how clinics handle add-ons like assisted hatching in our hospital directory, or contact our team for help finding one that fits your needs.
Disclaimer: This article is for educational purposes and does not replace professional medical advice. Always discuss treatment options with a qualified fertility specialist.
This article was written by the ProIVF Medical Editorial Team, reviewed by the ProIVF Medical Advisory Board, and is based on publicly available data from the Cochrane Database of Systematic Reviews, ASRM/ReproductiveFacts.org, and peer-reviewed medical literature.
Last updated: August 24, 2026
