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Time-lapse imaging

Treatment add-on with limited evidence

For most patients, having a routine cycle of proven fertility treatment is effective without using any treatment add-ons.


Amber traffic light


Time-lapse incubation and imaging is rated amber because there is conflicting evidence from randomised controlled trials (RCTs) to show that it is effective at improving the chances of having a baby for most fertility patients.

What does this traffic light rating mean?

Our traffic-light rated list of add-ons consists of three colours that indicate whether the evidence, in the form of high-quality RCTs, shows that a treatment add-on is effective at improving the chances of having a baby for most fertility patients. 

We give an amber symbol for an add-on where there is conflicting evidence from RCTs to show that an add-on is effective at improving the chances of having a baby for most fertility patients. This means that the evidence is not conclusive and further research is required, and the add-on should not be recommended for routine use.

Our traffic light ratings only indicate the effectiveness of a treatment add-on, at improving your chances of having a baby. Specific safety concerns about a treatment add-on are included under the dedicated section ‘Is this treatment add-on safe?’.

What is time-lapse incubation and imaging?

In IVF, time-lapse incubation and imaging is used to help select the embryos most likely to develop into a baby.

In conventional IVF, the embryologist will check the developing embryos each day under a microscope, which involves removing them from the incubator for a brief period.  

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 embryologist can then choose a specific embryo for implantation based on criteria such as rate of development and the number and appearance of cells.

What's the evidence for time-lapse imaging?

There have been various studies to try and see if time-lapse incubation and imaging can be effective at improving your chances of having a baby. Initial research has shown some promise, but it’s still very early days.

Indeed, being undisturbed while they grow may improve the quality of the embryos but there’s certainly not enough evidence to show that time-lapse incubation and imaging is effective at improving your chance of having a baby, which is something you may want to consider if it’s being offered to you at an extra cost.

At the June 2020 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.

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 do 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.

What are treatment add-ons?

  • optional additional treatments, also referred to as ‘supplementary’, ‘adjuvants’ or ‘embryology treatments’.
  • often claim to be effective at improving the chances of having a baby (live birth rate) but the evidence to support this for most fertility patients is usually missing or not very reliable.
  • likely to involve an additional cost on top of the cost of a routine cycle of proven fertility treatment. Some treatment add-ons can cost hundreds or thousands of pounds each.

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, from high-quality randomised control trials (RCTs), to show that they are effective at improving your chances of having a baby.

To make it easier to understand the scientific evidence for each treatment add-on we have developed our traffic-light rated list of add-ons.


Review date: 30 December 2023

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