Intermediate
Technical
In the Industry Vocabulary Test
Cleavage Stage
The early embryonic development period characterized by rapid cell divisions without overall size increase.
Full Definition
The cleavage stage encompasses the first few days of embryonic development, typically days 1-3 after fertilization, during which the embryo undergoes rapid mitotic divisions. These divisions, called cleavages, produce smaller cells called blastomeres without increasing the overall embryo size. Embryologists assess cleavage stage embryos based on cell number, symmetry, and fragmentation patterns. This stage is critical for determining embryo viability and transfer timing in assisted reproduction cycles.
In Context
- "The embryo showed normal progression through cleavage stage with symmetric divisions." — Embryology report
- "Cleavage stage transfer was performed on day 2 due to limited embryo availability." — Treatment summary
Also known as
early embryo stage
Contrasted with
blastocyst stage
Don't confuse with
morula stage
blastomere stage