Time-lapse embryo imaging in IVF: what the evidence says

Time-lapse imaging (TLI) takes a series of photos of developing embryos at regular intervals, often every few minutes, while they stay inside an incubator. Embryologists can then review how each embryo developed without taking it out for inspection.

How the system works

A time-lapse system combines an incubator that maintains stable temperature and gas levels with a built-in microscope, camera, and software. The software records when key events happen, such as the first cell divisions and the formation of the blastocyst. Embryologists use these timings, along with the embryo's appearance, when choosing which embryo to transfer.

What the evidence shows

TLI is often marketed as a way to improve success rates, but the evidence so far is limited. A Cochrane review found insufficient good-quality evidence of differences in live birth, miscarriage, stillbirth, or clinical pregnancy between time-lapse systems (with or without embryo selection software) and conventional incubation and assessment.

The UK fertility regulator, the HFEA, notes that for most patients a routine cycle of proven fertility treatment is effective without add-ons. It rates time-lapse incubation with automated (algorithm or AI) embryo analysis black for improving the chance of having a baby, meaning moderate/high quality evidence shows no effect.

Questions to ask your clinic

• Do you use time-lapse for all embryos, or is it an extra charge?
• How do you use the images when selecting embryos?
• What evidence do you rely on to say it helps patients like me?

TLI can be a useful lab tool, especially for keeping embryos undisturbed and giving embryologists more information. It is reasonable to use it, but not to pay extra expecting a proven boost in your chance of having a baby.