INSIDEEMBRYO · FERTILITY GLOSSARY
A blastocyst is an advanced preimplantation embryonic stage that develops following cleavage, compaction and morula formation. Its structure is characterised by a fluid-filled blastocoel cavity and differentiation into the inner cell mass and trophectoderm. The inner cell mass contributes primarily…
A blastocyst is an advanced preimplantation embryonic stage that develops following cleavage, compaction and morula formation. Its structure is characterised by a fluid-filled blastocoel cavity and differentiation into the inner cell mass and trophectoderm. The inner cell mass contributes primarily to formation of the embryo proper, whereas the trophectoderm participates predominantly in extraembryonic and placental development. Progressive accumulation of blastocoelic fluid produces blastocyst expansion and thinning of the surrounding zona pellucida. Before implantation can proceed, the expanding blastocyst normally undergoes hatching from the zona pellucida.
For education, not individual medical advice. Ask your fertility team about your care.