Where next?
Back to Treatment add-ons information
Share your experiences by joining our Patient Engagement Forum.Time-lapse imaging and incubation
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 ratings do not tell you how much that treatment add-on improves your chances of having a baby – please discuss this with your clinic.
What is time-lapse incubation and imaging?
In IVF, time-lapse incubation and imaging is theoretically used to help select the embryos most likely to develop into a baby.
In conventional IVF, the embryologist will check the developing embryos most days under a microscope, which involves removing them from the incubator for a brief period. The embryos will be graded based on how the embryos appear when checked, usually by looking at the number and appearance of cells.
Time-lapse incubation and imaging allow the embryologist to take thousands of images of the embryos as they grow without disturbing them. Not only does this mean the embryos do not have to be removed from the incubator, it also allows the embryologist to get a continuous view of each embryo as it develops, rather than just viewing them once a day.
The degree to which observations from time lapse images are used by clinics, for embryo assessment and selection, varies. Some clinics and time lapse system manufacturers have developed algorithms (or selection models) to rank or score embryos.
The embryologist can then choose a specific embryo for implantation based on criteria such as rate of development and the number and appearance of cells.
| Ratings for time-lapse imaging and incubation | |
|---|---|
| Rated black for improving the chances of having a baby for most fertility patients when using automated analyses of embryos
Black traffic light
|
For most fertility patients, using a time lapse incubator with automated analyses of embryos, ie by using algorithms or artificial intelligence, is rated black for improving the chances of having a baby. This is because, on balance, the findings from moderate/high quality evidence shows that this add-on has no effect on the treatment outcome. |
| Rated black for improving the chances of having a baby for most fertility patients when using manual analyses of embryos
Black traffic light
|
For most fertility patients, using a time lapse incubator with manual analyses of embryos, ie by an embryologist, is rated black for improving the chances of having a baby. This is because, on balance, the findings from moderate/high quality evidence shows that this add-on has no effect on the treatment outcome. |
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) stated 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 time-lapse imaging?
There have been several studies, including 5 moderate/high quality studies, investigating whether there are improvements in the chances of having a baby when using a time lapse incubator with automated or manual grading of embryos. Overall, the evidence from RCTs shows that time lapse imaging is not effective at improving the chances of having a baby for most patients undergoing IVF.
Time-lapse imaging has been shown to be a convenient and effective way to incubate embryos and provide a continuous view of embryo development which could offer benefits like enabling the embryologists to observe all fertilisation and developmental aspects of an embryo without disturbance.
At the June 2020 and July 2023 Scientific and Clinical Advances Advisory Committee (SCAAC) meeting the Committee evaluated the evidence. Minutes of this discussion and the evidence used to inform this discussion are available on the SCAAC webpage. SCAAC reviewed the evidence for improving the chances of having a baby in fresh cycles, SCAAC did not review other claimed benefits such as increased embryo quality.
This Cochrane review has further information on the evidence for time-lapse incubation and imaging.
Is this treatment add-on safe?
Time-lapse imaging and incubation does not carry any additional known risks for the person undergoing fertility treatment or any child born as a result of fertility treatment.
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 time-lapse imaging and incubation:
| Kirkegaard 2012 | 10.1007/s10815-012-9750-x |
| Van Blerkom 2014 | 10.1016/j.rbmo.2013.11.012 |
| Park 2015 | 10.1093/humrep/deu316 |
| Wu 2016 | 10.1186/s12958-016-0181-x |
| Barberet 2018 | 10.1016/j.fertnstert.2017.10.008 |
| Chen 2020 | 10.1093/humrep/deaa268 |
| Guo 2022 | 10.3389/fphys.2021.794601 |
| Goodman 2016 | 10.1016/j.fertnstert.2015.10.013 |
| Kaser 2017 | 10.1093/humrep/dex231 |
| Alhelou 2018 | 10.1016/j.repbio.2017.12.003 |
| Kovacs 2019 | 10.1016/j.ejogrb.2018.12.011 |
| Ahlstrom 2022 | 10.1093/humrep/deac020 |
| Kahraman 2013 | 10.1177/205891581200300204 |
| Rubio 2014 | 10.1016/j.fertnstert.2014.07.738 |
| Insua 2017 | 10.1016/j.fertnstert.2017.06.031 |
| Yang 2018 | 10.1093/humrep/dey047 |
| Meng 2022 | 10.1016/j.fertnstert.2022.02.015 |
| Zhang 2022 | 10.1016/j.rbmo.2022.06.017 |
| Guo 2022 | 10.3389/fphys.2021.794601 |
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. The HFEA provides information on add-ons that meet the following criteria:
- 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 are published scientific studies which claim to demonstrate that the add-on improves the chances of having a baby 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 a routine cycle of proven fertility treatment is effective without using any treatment add-ons. If you are paying directly for your own treatment, you may want to think about whether it might be more effective and/or affordable to pay for multiple routine proven treatment cycles, rather than spending large sums of money on a single treatment cycle with treatment add-ons that haven’t been proven to be effective at increasing the likelihood of you having a baby.
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 are effective at improving 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: 20 October 2025
