What do the grades on my embryo report actually mean?

A day-by-day record of your eggs and embryos, from egg collection to transfer or freezing.

Day 0 lists how many eggs were collected and how many were mature. Day 1 records which eggs fertilised normally. Days 2 and 3 count the cells in each embryo. Days 5 and 6 grade the blastocysts. The last lines say which embryo was transferred, which were frozen, and which stopped growing.

The number says how far the blastocyst has expanded; the two letters rate its two groups of cells.

Under the Gardner system most labs use, expansion runs from 1 (early blastocyst) to 6 (fully hatched out of its shell). The first letter grades the inner cell mass, which becomes the baby. The second grades the trophectoderm, the outer layer that becomes the placenta. A means many tightly packed cells, B fewer or looser, C very few. Some labs follow the ESHRE/ALPHA consensus and write 1, 2 and 3 (good, fair, poor) instead of letters.

On day 3, embryos are judged mainly by how many cells they have, how even those cells are, and how much fragmentation there is.

The ESHRE/ALPHA consensus expects about 4 cells on day 2 and about 8 on day 3. Fragments are small pieces of cell debris; a little is common. Labs turn this into a grade such as 1, 2 or 3, or A, B or C, but the scales differ. Check the key on your own report.

A better grade helps choose which embryo to transfer first, but it cannot promise a pregnancy, and a lower grade does not rule one out.

Grading is an embryologist's reading of how an embryo looks. It cannot see the chromosomes, which are the commonest reason a transfer fails. The 2025 ESHRE/ALPHA consensus says the outer layer and expansion matter most when ranking blastocysts. When two blastocysts look alike, labs usually choose a day 5 one before a day 6 one. Embryo testing (PGT) looks at chromosomes and may be considered in selected cases, discussed with you.

Some embryos stop growing (arrest) or do not reach a freezable blastocyst by day 6 or 7.

This is common. It usually reflects the egg or sperm the embryo came from, not something the lab did. Each lab sets its own freezing criteria, and your report should say why an embryo was not frozen. [CONFIRM: Jananam's freezing criteria] If embryos arrest at the same stage cycle after cycle, that pattern matters, and it is worth a doctor reading every report together.

At Jananam, never more than two, and usually one.

Transferring more embryos raises the risk of twins, which carry more risk for mother and babies. A good-quality single embryo is the usual choice, and the rest can be frozen for later.