Is blastocyst culture needed before PGT-A?

After eggs are fertilised, embryos are monitored as they develop in the laboratory. Blastocyst culture continues this process until an embryo may be suitable for biopsy. The laboratory removes a small group of cells from the outer part of the blastocyst for preimplantation genetic testing for aneuploidy, while the embryo is handled according to the clinic’s freezing and transfer plan.

Not every embryo reaches the blastocyst stage, and not every blastocyst is suitable for biopsy or testing. PGT-A can provide chromosome information for embryos that are tested, but it cannot make an embryo develop or remove every uncertainty from treatment.

Ask your fertility team when blastocyst assessment, biopsy, freezing, and PGT-A results fit into your cycle. Clarify what happens if no embryo reaches a suitable stage, how results are reported, and whether transfer is planned in a later cycle. Review the clinic’s explanation of [PGT-A](/treatments/fertility-and-assisted-reproduction/pgt-a/) before consenting so you understand what the test can and cannot answer.

Contact your clinic if you miss a medication instruction, cannot attend a planned monitoring appointment, or do not understand a result or consent form. Seek urgent medical care for severe pain, heavy bleeding, fainting, fever, or breathing difficulty during fertility treatment. These symptoms need clinical assessment and are not explained by the timing of embryo testing alone.

Why is PGT-A being considered for me? What stage must an embryo reach before biopsy? How are embryos handled while results are pending? What options exist if there are no suitable embryos to test or transfer?