Time-Lapse Embryo Monitoring – is it worth the money?

Eleanor Wharf, Clinical Embryologist & Fertility Coach, UK: I have been working closely with patients to explain laboratory processes in an accessible way and support informed decision-making throughout fertility treatment for over 25 years now.

Tomáš Rieger, PhD, Head Embryologist at GYNEM Fertility Clinic, Czechia: I lead the embryology laboratory and have extensive experience implementing and evaluating time-lapse systems in clinical IVF practice. He’s been working as an Embryologist since 2009. I’ve been working at Gynem, which is a small family clinic in Prague, since 2013.

Eleanor Wharf, Clinical Embryologist & Fertility Coach, UK: Time-lapse embryo monitoring is a method of culturing embryos inside a specialised incubator that contains an internal camera. The camera takes images of the embryos at regular intervals, usually every 10 minutes, creating a continuous video of embryo development from fertilisation onwards.

The key difference from conventional incubation is that embryos do not need to be removed from the incubator for assessment. Traditionally, embryos are taken out once or twice a day to be checked under a microscope. With time-lapse monitoring, embryos remain undisturbed in a stable environment while development is observed remotely.

Tomáš Rieger, PhD, Head Embryologist at GYNEM Fertility Clinic, Czechia: Yes, there are several types of time-lapse incubators produced by different manufacturers. They differ in both hardware and software.

Some systems use individually sealed chambers for each patient’s embryos, meaning that opening one chamber does not affect the conditions of others. Other systems use shared chambers. Differences also exist in image resolution, frequency of image capture, annotation tools, and software used to analyse embryo development.

Tomáš Rieger, PhD, Head Embryologist at GYNEM Fertility Clinic, Czechia: Time-lapse monitoring is primarily a laboratory tool that improves embryo observation and workflow. However, current scientific evidence does not show a clear improvement in pregnancy or live birth rates when compared to conventional incubation.

The advantage of time-lapse lies in maintaining stable culture conditions and providing more detailed information about embryo development, rather than directly increasing success rates.

Tomáš Rieger, PhD, Head Embryologist at GYNEM Fertility Clinic, Czechia: Time-lapse monitoring allows embryologists to assess not only how an embryo looks at a single moment, but also how it develops over time. We can observe the timing of cell divisions, compaction, and blastocyst formation, and identify abnormal developmental patterns that would not be visible with static observations.

This additional information can support embryo selection when multiple embryos are available, but it does not guarantee that the selected embryo will implant or result in a live birth.

Tomáš Rieger, PhD, Head Embryologist at GYNEM Fertility Clinic, Czechia: Time-lapse monitoring does not allow us to reliably distinguish between euploid, mosaic, or aneuploid embryos. Decisions in these cases should be guided primarily by genetic testing results rather than time-lapse data.

Mosaic embryos may still have implantation potential because the biopsy samples only a small number of trophectoderm cells. Segmental abnormalities generally carry a higher risk. These decisions should always involve genetic counselling and individualised clinical discussion.

Eleanor Wharf, Clinical Embryologist & Fertility Coach, UK: There is evidence that embryos can undergo a process of self-correction, where abnormal cells may stop dividing while normal cells continue. This phenomenon has been observed in early embryo development.

However, self-correction cannot be predicted with certainty and does not occur in all embryos. It should not be assumed that all abnormal embryos will self-correct. It is important to be cautious when discussing self-correction with patients. While it can happen, it is not something we can reliably measure or predict. This is why careful counselling and evidence-based decision-making are essential.

Eleanor Wharf, Clinical Embryologist & Fertility Coach, UK: Time-lapse monitoring can help distinguish between true 3PN embryos and situations where two normal pronuclei are present along with a smaller structure, such as a micronucleus. In some cases, embryos initially classified as 3PN may still develop normally.

However, true 3PN embryos are usually chromosomally abnormal, and genetic testing is strongly recommended before considering transfer.

Tomáš Rieger, PhD, Head Embryologist at GYNEM Fertility Clinic, Czechia: Transferring untested 3PN embryos carries significant risks, including chromosomal abnormalities and molar pregnancy. Time-lapse helps clarify pronuclear behaviour, but it does not replace genetic testing.

Eleanor Wharf, Clinical Embryologist & Fertility Coach, UK: Most embryos today are frozen using vitrification. During warming, embryos are rapidly thawed and rehydrated using specific solutions. After thawing, embryos are monitored for survival and re-expansion, which indicates viability.

Time-lapse is not typically used during the thawing process itself, but embryos may be returned to a time-lapse incubator afterwards for observation.

Tomáš Rieger, PhD, Head Embryologist at GYNEM Fertility Clinic, Czechia: Many laboratories now use single-step culture media, where embryos remain in the same media from fertilisation to blastocyst stage. Evidence shows no significant difference in outcomes compared to sequential media, provided the laboratory conditions are well controlled.

Embryos that are developmentally competent will usually reach the blastocyst stage regardless of whether media is changed.

Eleanor Wharf, Clinical Embryologist & Fertility Coach, UK: Time-lapse monitoring does not improve live birth rates, so patients who do not use it are not disadvantaged in terms of outcomes. In some healthcare systems, it is included as standard, while in others it is offered as an optional add-on due to cost and equipment limitations.

Transparency is essential. Patients should be clearly informed about what time-lapse can and cannot offer.

Tomáš Rieger, PhD, Head Embryologist at GYNEM Fertility Clinic, Czechia: From a laboratory perspective, time-lapse improves workflow and observation, but it is not essential for achieving pregnancy. Clinics without time-lapse technology can achieve equivalent results.

Tomáš Rieger, PhD, Head Embryologist at GYNEM Fertility Clinic, Czechia: Time-lapse can be especially useful in cycles involving genetic testing, where precise timing of blastocyst development and biopsy is important. It also improves fertilisation assessment and allows embryologists greater flexibility in laboratory scheduling.

Eleanor Wharf, Clinical Embryologist & Fertility Coach, UK: No. Clinics without time-lapse technology can achieve the same pregnancy and live birth rates using conventional incubation methods. Patients should focus on overall laboratory quality, experience, and transparency rather than a specific technology.