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Assisted hatching
For most patients, having a routine cycle of proven fertility treatment is effective without using any treatment add-ons.
Our ratings indicate whether the evidence from studies shows that a treatment add-on is effective at improving treatment outcomes for someone undergoing fertility treatment. Our rating does not tell you how much that treatment add-on improves your chances of having a baby – please discuss this with your clinic.
What is assisted hatching?
The egg and early embryo are surrounded by a thick layer of special proteins called the zona pellucida. Before an embryo can implant in the womb it has to break out or ‘hatch’ from its zona pellucida. Assisted hatching using acid, lasers or other tools to thin or make a hole in the zona pellucida is thought to help the embryo to ‘hatch’.
| Rated outcomes for assisted hatching | |
|---|---|
| Rated grey for increasing the chances of having a baby for most fertility patients
Grey traffic light
|
We cannot rate the effectiveness of this add-on at improving the chances of having a baby for most fertility patients, as there is insufficient moderate/high quality evidence. |
What do ratings mean?
There are five ratings that indicate whether a treatment add-on is effective at improving treatment outcomes for someone undergoing fertility treatment, according to the evidence from studies. To make it easier to understand the scientific evidence for each treatment add-on we have a range of symbols and colours for each rated add-on below.
Green traffic light
On balance, findings from high quality evidence shows this add-on is effective at improving the treatment outcome.
Yellow traffic light
On balance, it is not clear whether this add-on is effective at improving the treatment outcome. This is because there is conflicting moderate/high quality evidence – in some studies the add-on has been found to be effective, but in other studies it has not.
Grey traffic light
We cannot rate the effectiveness of this add-on at improving the treatment outcome as there is insufficient moderate/high quality evidence.
Black traffic light
On balance, the findings from moderate/high quality evidence shows that this add-on has no effect on the treatment outcome.
Red traffic light
There are potential safety concerns and/or, on balance, findings from moderate/high quality evidence shows that this add-on may reduce treatment effectiveness.
All treatment add-ons on our list will have a rating to indicate whether the evidence shows that the treatment add-on is effective at improving the chances of having a baby for most fertility patients. Some treatment add-ons on our list may also have additional ratings for specific treatment outcomes. For example, whether the evidence shows that the treatment add-on reduces miscarriage. There may also be further ratings for specific patient groups, for example whether the evidence shows that the treatment add-on is effective for those who are aged over 40. Please see the individual webpages for each treatment add-on for their ratings.
An agreement between the HFEA and other professional and patient bodies (the 19th October 2023 consensus statement) states that treatments that have no strong evidence of their safety and/or effectiveness should only be offered in a research setting. Patients should not be charged extra to take part in research, including clinical trials.
What’s the evidence for assisted hatching?
The National Institute for Clinical Excellence (NICE) is the national body advising doctors on treatments. It says:
“Assisted hatching is not recommended because it has not been shown to improve pregnancy rates.”
NICE also says that further research is needed to find out whether assisted hatching influences birth rates and to examine the consequences for children born as a result of this procedure.
Some believe assisted hatching can lead to higher birth rates in specific subgroups of patients. There is however no high-quality evidence to support the use of assisted hatching for any patient.
At the July 2023 Scientific and Clinical Advances Advisory Committee (SCAAC) meeting the Committee evaluated the evidence base for assisted hatching. Minutes of this discussion and the evidence used to inform this are available on the SCAAC webpage. The list of studies reviewed can be found under the section titled ‘Studies reviewed for this treatment add-on’.
Is this treatment add-on safe?
Assisted hatching does not carry any known additional risks for the person undergoing fertility treatment. However, there is always some risk of damaging embryos with these types of procedures.
If you have any questions about the safety and risks, your clinic will be able to discuss whether a treatment add-on would be safe for you to use considering your specific medical history and circumstances.
Studies reviewed for this treatment add-on
The SCAAC have reviewed the following studies for assisted hatching:
| Balaban 2006 | 10.1093/humrep/del097 |
| Ge 2008 | RBMO 2008;16(4):589-96. |
| Valojerdi 2010 | 10.1016/j.rbmo.2009.11.002 |
| Fang 2010 | 10.1016/j.fertnstert.2009.08.014 |
| Debrock 2011 | 10.1093/humrep/der161 |
| Figueria 2012 | 10.1016/j.ejogrb.2012.05.022 |
| Ren 2013 | 10.1007/s10815-013-9984-2 |
| Wan 2014 | 10.1016/j.rbmo.2014.01.006 |
| Wang 2016 | 10.3892/br.2016.716 |
| Knudtson 2016 | F&S 2016;106(3) Suppl:e141 |
| Safari 2017 | 10.1016/j.repbio.2017.05.003 |
| Elnahas 2017 | 10.1016/j.mefs.2017.05.006 |
| Kirienko 2019 | 10.1016/j.rbmo.2019.06.003 |
| Sagoskin 2007 | 10.1016/j.fertnstert.2006.07.1498 |
| Ge 2008 | 10.1016/j.fertnstert.2006.07.1498 |
| Balakier 2009 | 10.1016/j.fertnstert.2008.07.1729 |
| Hagemann 2010 | 10.1016/j.fertnstert.2009.01.116 |
| Kutlu 2010 | 10.1007/s10815-010-9431-6 |
| Razi 2013 | Iran J reprod Med 2013;11(12):1021-6. |
| González-Ortega 2015 | Ginecol Obstet Mex 2015;83:670-9. |
| Shi 2016 | 10.1177/1933719116641764 |
| Chang 2016 | F&S 2016;106(3) Suppl:e314 |
| Nada 2018 | 10.1007/s00404-017-4604-5 |
What are treatment add-ons?
In vitro fertilisation (IVF) and intrauterine insemination (IUI) are established treatments that have been proven effective for most patients. Treatment add-ons are optional non-essential treatments that may be offered in addition to such proven fertility treatment. Treatment add-ons are:
- Additional treatments (to the core treatment e.g. IVF or IUI) that are being offered to the general patient population in licensed fertility clinics in the UK,
- Where there is published scientific literature which claims to demonstrate that the add-on improves live birth rates or other treatment outcomes rated by the HFEA; but
- where evidence of effectiveness for the use of the treatment in a clinical setting is lacking or absent; and
- where patients need unbiased information about the effectiveness and risks of this treatment
It is important to keep in mind that for most patients, having routine cycles of proven fertility treatment are effective without using any treatment add-ons. If you are paying for your own treatment, you may want to think about whether it might be better to pay for multiple cycles of IVF or IUI, rather than spending large sums of money on a single treatment cycle with treatment add-ons that haven’t been proven to be effective.
We aim to publish clear and reliable information about some of the treatment add-ons that don’t have enough evidence to show that they improve your chances of having a baby and other relevant treatment outcomes. This provides useful information to patients and allows them to question the use of add-ons.
Review date: 19 October 2025
