Why Embryology Labs Use More Than One Kind of Incubator

An embryology laboratory rarely relies on a single incubator model. A working lab may run benchtop incubators alongside larger multi-chamber units, and may include time-lapse imaging incubators next to standard ones. This is not usually a sign that one design is reserved for “better” embryos. It is more often a practical answer to three pressures that pull in different directions: keeping each embryo’s environment stable, keeping different patients’ embryos physically separate, and keeping the lab running when equipment needs service or patient numbers rise.

For patients researching PGT and IVF in Thailand, incubator design is a reasonable thing to be curious about. It is also easy to over-read. No incubator type, on its own, guarantees an embryo will develop, test normally or lead to a pregnancy. What the equipment mix tells you is something about how a laboratory organises its work — and that is worth understanding before you compare clinics.

What an incubator is actually doing

After fertilisation, embryos are kept in culture medium inside an incubator that aims to hold a steady temperature, a controlled gas mixture and stable humidity. Small fluctuations in temperature or gas concentration, or repeated opening of an incubator door, change the environment around the embryos. Much of incubator design is therefore about stability: how quickly conditions recover after the door opens, how evenly conditions are held across the chamber, and how often the embryos need to be disturbed at all.

Two gas settings come up often. Carbon dioxide (CO2) is used to keep the culture medium at a suitable pH. Some incubators also control oxygen (O2), often described as “tri-gas” because they manage CO2, O2 and nitrogen. Whether a lab uses atmospheric-oxygen or reduced-oxygen conditions is a laboratory protocol decision; patients should not assume one setting is universally superior from a brochure alone.

Benchtop versus large multi-chamber incubators

The two broad families differ mainly in scale and in what happens when one part of the lab is busy.

• Benchtop (desktop) incubators usually hold a small number of dishes or a single patient’s group. Because each unit is small, opening one affects only the embryos inside it. That suits separation between patients and can mean a faster recovery of conditions after access. The trade-off is that many small units need more hands-on management and more individual monitoring.
• Large multi-chamber incubators hold many embryos across separate compartments or drawers. They can support a high patient load with fewer separate machines, and each compartment may be opened independently. The design question is how well conditions are held across the whole unit and how the lab tracks which sample sits where.

Neither layout is automatically better for an individual embryo. A lab may choose based on its patient volume, its staffing, its physical space and how it prefers to organise daily work.

Time-lapse incubators: a different purpose

Time-lapse incubators combine culture with a camera that images embryos at intervals, so the embryologist can review development without taking the dish out. The potential appeal is fewer disturbances and a continuous record. The important caveat is that seeing more images is not the same as proving better outcomes. If a clinic offers time-lapse, ask what it uses the images for — routine monitoring, selection decisions, or both — and whether its use changes anything about your cycle or its cost.

Why a lab might deliberately separate embryos

Laboratory workflow is organised around avoiding mix-ups and cross-contamination, and around not disturbing one patient’s embryos while handling another’s. Using separate incubators, or separate compartments within one incubator, is one way to do that. It also means a problem in one unit — a door left open, a sensor fault, a unit taken out for servicing — does not affect every embryo in the lab at once.

This is where the phrase “different kinds of incubator” often really means “different jobs”. One unit may be used for a particular stage of culture, another as backup capacity, and another for cases where the lab wants extra separation. The reasoning is operational, and it is reasonable to ask a clinic to explain its own arrangement rather than assume a standard one.

Redundancy, backup and staggered workloads

IVF laboratories run on schedules that are not perfectly even. Patient starts are staggered, some cycles yield many embryos and others few, and equipment needs calibration and service. A mix of incubator types gives a lab options: it can move work between units, keep spare capacity for a busy week, and maintain a backup if a unit is out of service. For patients, the useful question is not “how many incubators?” but “what happens to my embryos if a unit fails or needs servicing?” A lab that can describe its backup plan is telling you something concrete about how it manages risk.

What monitoring looks like from the outside

Incubators are typically monitored for temperature and gas, with alarms and records. The details — how often readings are checked, what triggers an alarm, who responds, and how deviations are documented — vary between laboratories. These are fair questions for a clinic, and they are the kind of information a laboratory quality guide can help you frame. If you are comparing providers, it helps to ask the same questions in the same order so the answers are comparable.

What this means for PGT patients

PGT involves biopsy of cells from an embryo, and the sample is then tested. The incubator’s job is to support the embryo before and after that handling. A well-organised laboratory will be able to explain how embryos are tracked through biopsy and testing, and how the incubator setup fits into that pathway. None of this establishes that a particular clinic will give you a better chance; it tells you whether the laboratory can describe its own process clearly.

It is also worth keeping PGT in perspective. PGT-A assesses chromosome number in sampled cells and has limitations, including the possibility of incorrect findings; a result does not guarantee a successful pregnancy or a healthy child. PGT-M and PGT-SR address different questions — a known monogenic condition and a chromosomal structural rearrangement, respectively — and suitability should be discussed with your treating team and a genetic counsellor. Incubator design does not change those fundamentals.

Questions worth putting in writing

If laboratory setup matters to your decision, ask for the information in writing so you can compare clinics on the same basis. Useful questions include:

• Which incubator types does the laboratory use, and what is each used for?
• How are embryos from different patients kept separate?
• How are temperature and gas monitored, and what happens if a reading goes out of range?
• What is the backup plan if an incubator fails or needs servicing?
• If time-lapse is used, what is it used for, and does it change the fee?
• Who in the laboratory can answer follow-up questions, and how are those answers shared with you?

You can ask your treating clinician about how these laboratory arrangements relate to your own cycle. A coordination service can help you organise the questions, request written information and keep track of what has been confirmed, but it does not interpret results or advise on treatment. If you are still at the stage of shortlisting providers, a structured comparison of laboratory information can sit alongside broader research; the countrywide shortlist research page is one optional starting point, not a ranking of outcomes.