EmbryoScope, Time-Lapse and Continuous Embryo Monitoring

Time-lapse embryo monitoring is the imaging of your embryo at regular intervals in the IVF laboratory without taking it out of the incubator. EmbryoScope, which you will often meet on the internet, is the commercial name of one of these systems. Studies conducted so far have not shown that this method increases the chance of pregnancy or live birth. There is also no known additional risk. You decide together with your doctor and embryologist whether this method is meaningful for you. This information offers a general framework; it does not replace an individual assessment.

What is the difference between time-lapse and a standard incubator?

In the standard method your embryos develop in an incubator (a culture cabinet) in which temperature, humidity and gas ratio are controlled. On certain days the embryologist takes the dish out of the incubator for a short time in order to examine the embryo under the microscope. In time-lapse systems, on the other hand, a camera is placed inside the incubator. The camera automatically records the image of the embryo at certain intervals, and the embryologist watches these images on a screen.

What do uninterrupted culture and selection from images mean?

These systems have two separate functions, and the two are often confused:

• Uninterrupted culture: Your embryos develop without being taken out for daily checks.
• Assessment and selection from images: The images recorded make it possible to see when the embryo moved to which stage and to select the embryo to be transferred.

Reviews also deal separately with the use of time-lapse systems for both incubation and assessment. Although it sounds logical that the embryo is never taken out, it has not been shown in studies that this increases the pregnancy rate.

What is morphokinetics, that is, developmental timing data?

Morphokinetics is the timing of the developmental steps of the embryo: when cell divisions take place, at what intervals they proceed, and so on. In standard assessment your embryo is looked at once or several times a day; time-lapse also records as images what happens in between. According to the current view on this subject, this detailed data can be used to improve the timing of the standard assessment. The same view also states that, because many laboratories do not have this device, daily standard assessment still continues.

Does software or the embryologist choose your embryo?

In some systems there is also software that produces an automatic score from the images. This software is not a decision mechanism that replaces the embryologist; the final decision is determined by expert assessment and your situation together. You can ask your doctor how the software score is used and who makes the final decision.

What do studies say about the chance of pregnancy and live birth?

A systematic review assessed together the studies comparing time-lapse systems with standard incubation. Whether there is a difference between them in terms of live birth was found to be uncertain, and the reliability of the evidence was assessed as low or very low. The researchers concluded that there is no good-quality evidence showing that this method is more effective or less effective than standard practice.

Two large controlled studies conducted afterwards have not changed this picture either. In a multicentre, double-blind, three-arm study, uninterrupted culture and software-assisted time-lapse selection were compared with standard culture; no significant difference between the groups was seen in ongoing pregnancy rates. This study is specific to a particular piece of software. In another study carried out in centres in the United Kingdom and Hong Kong, the researchers also reported that they saw no improvement in live birth, clinical pregnancy and pregnancy loss. These studies are specific to particular devices, software and patient groups; it should not be thought that the results will apply in the same way to every device and every patient.

How does the regulator in the United Kingdom assess time-lapse?

The regulator in the United Kingdom classifies add-on practices of this kind to treatment by colour according to the level of evidence. Time-lapse incubation falls in the lowest category for most patients in terms of increasing the chance of live birth. This means that evidence from medium- and high-quality studies has not shown that this practice increases the chance of live birth. This classification does not mean "harmful"; no known additional risk has been reported. This assessment looked only at the evidence on the chance of live birth in a fresh cycle; it did not assess other possible benefits such as continuous observation. This classification is specific to the United Kingdom; there is no official grading or guideline specific to this practice in Turkey.

Why does the evidence remain uncertain?

Different devices, different software and different patient groups have been used in the studies. In addition, there are not enough independent studies for special situations such as advanced age, repeated failure or very few embryos. For this reason there is not enough basis to say either "it is useful in particular patients" or "it is useless". What determines success is many factors, such as your age, the number and quality of embryos, and laboratory conditions. The presence of a device alone does not change this outcome.

Is time-lapse necessary for everyone?

The evidence we have does not show that time-lapse is necessary routinely for all IVF patients. Its use is your doctor's clinical preference; this does not mean a superiority proven by controlled studies.

What questions can you ask your doctor before deciding?

• Is a time-lapse system used at the centre, in which patients and for what purpose?
• Is a software score used in selecting the embryo? Who makes the final decision?
• What can this practice change in my situation, and what might it not change?
• Does the practice have an additional cost?
• What does the consent and information document say about this practice?

What should you consider about safety and additional cost?

Assessments done show that time-lapse carries no known additional risk for you or for your baby. Follow-up data of one study also reported that pregnancy and newborn outcomes were similar to standard culture. "No known additional risk has been reported" does not mean certainty for every individual situation.

The main point to watch for is elsewhere. The use of time-lapse often brings a marked additional cost to the treatment. You need to assess together with your doctor whether you will pay an additional fee for a practice with limited evidence. Another risk is the idea that the presence of the device brings success by itself; this idea can lead to unrealistic expectations. If, during the IVF process, you experience urgent symptoms such as severe pain, heavy bleeding, rapid weight gain, swelling or shortness of breath, you can look at the relevant treatment pages and contact your doctor.

Are time-lapse, PGT and artificial intelligence the same thing?

No. Time-lapse is an imaging and culture system. PGT is a genetic test done on cells taken from the embryo. Artificial intelligence is a general name given to software that analyses images or data; time-lapse images can be used as input to one of these pieces of software. The three do not take the place of one another. For detailed information you can look at the pages on embryo grading, AI-assisted embryology and PGT.