Blastocyst culture (blastocyst transfer)

What blastocyst culture involves

In IVF, the UK fertility regulator, the HFEA, says “the embryos are allowed to develop for between two and six days.” A blastocyst is an embryo at the later end of that range: “Blastocyst stage embryos are selected on day five of their development.”

The HFEA explains the difference in its own terms: “The difference is that because blastocyst embryos have been able to develop for longer in the lab it's easier for the embryologist to select the embryos that are most likely to implant in the womb.”

Blastocysts can also be frozen. The HFEA says “Embryos can be frozen at different stages of their development – when they're just a single cell, at the two to eight cell stage or later in their development (called the blastocyst stage).” And genetic testing of embryos usually happens at this stage: “PGT-A is now mostly carried out at the blastocyst stage on day five or six.” See PGT.

When it is not used

The HFEA says “Some women or couples may be less likely to have a blastocyst transfer because the embryologist is concerned they'll end up with very few or no embryos if a lot of the embryos don't survive to the blastocyst stage.” Whether it is appropriate in a particular case is a clinical decision for the treating doctor. This directory does not make that judgement.

On how many to transfer, the HFEA says “It's best practice to have only one embryo put back.” Blastocyst culture sits inside IVF or ICSI; it is not a treatment on its own.

What the regulator says about the downside

The HFEA states the downside plainly: “However, not all embryos that are left to the blastocyst stage will survive and in some cases a couple could have no embryos available to transfer to the womb. There's no way of knowing if the embryo had been transferred at the earlier cleavage stage, whether it could have continued to a successful pregnancy.”

India’s ART (Regulation) Rules, 2022 set out two levels of clinic:

• A Level 1 clinic is one where “only IUI is carried out as part of treatment”.
• A Level 2 clinic is one where “all/advanced investigations, diagnostic and therapeutic procedures in ART are carried out”.

Because a Level 1 clinic may carry out only IUI, Blastocyst culture is Level 2 work.

That is why each clinic below shows the level the national registry records for it. Of the listings below, 98 are registered as Level 2, 13 as Level 1, and 41 have no level in the registry extract. This directory does not know why a Level 1 clinic names Blastocyst culture. A clinic may send patients to a partner Level 2 laboratory, or its website may describe services it does not provide on site. Ask the clinic where the Blastocyst culture itself is done, and check its registration on the National ART & Surrogacy Registry.