For everyone going through IVF
Understand what happens to your embryos.
The lab side of IVF, explained the way an embryologist would explain it to family. Plain words. No promises. In English, and in your language.
Day 0
Mature egg
one cell, one polar body
Day 1
Fertilised
two pronuclei
Day 2
4 cells
first divisions
Day 3
8 cells
grading begins
Day 4
Morula
cells compact
Day 5
Blastocyst
cavity, inner cell mass
Ask, any time
An assistant that only knows what we've checked.
It answers from our reviewed pages and nothing else. It will not guess your chances, read your report, or pretend to be your clinic. When it doesn't know, it says so — and we write that page next.
You
My embryo is 3BB and I'm 38. What are my chances?
Embryologics
I can't estimate your chances — only your clinic can, with your full picture. What I can tell you: 3BB is a full blastocyst with good cells in both the inner cell mass and the outer layer. It's a commonly transferred grade with good pregnancy rates.
Read more: What your embryo grade means (and what it doesn't)
For patients
Wherever you are, start there.
Short pages for each step — before you begin, egg collection, the embryo days, transfer, the two-week wait, and what to ask if it doesn't work.
Before you start
AMH, AFC and 'ovarian reserve': what the numbers predict — and what they don't
Anti-Müllerian hormone and antral follicle count predict how many eggs a stimulation may produce. They say much less about egg quality or your chance of a baby.
Freezing & transfer
How embryo freezing works — and how safe it is
Vitrification explained: how embryos are frozen in seconds, why survival rates are high, how long they can stay frozen, and what 'freeze-all' means.
Tests & add-ons
PGT-A (embryo genetic testing): what it can and can't tell you
How embryos are biopsied and tested for chromosome number, what 'euploid', 'aneuploid' and 'mosaic' mean, who benefits, and the limits everyone should know before paying for it.
Eggs & sperm
The sperm sample: what the lab does with it and what the report means
Count, motility, morphology, DNA fragmentation — what the numbers mean, what 'sperm washing' is, and why one poor result rarely tells the whole story.
In the lab
What actually happens in the IVF lab
A walk through the days your eggs, sperm and embryos spend with the embryologists — from egg collection to transfer or freezing — in plain language.
Embryos & grading
What your embryo grade means (and what it doesn't)
4AA, 3BB, Grade 1, 8-cell — how embryologists grade embryos on day 3 and day 5, what the letters and numbers mean, and why a lower grade is not a verdict.
For IVF labs and clinics
Quality habits, free, one sheet at a time.
Log QC every morning. Score the lab every month. Document the fix when something breaks. Plain Excel your lab can adopt this week — no login, no patient data, no strings.
For embryologists
When something in the lab goes wrong.
Problem-first guides — fertilisation dropped, blastocysts stalled, survival fell — and a registry of media, incubators and techniques with what to check first. Neutral. The IFU always wins.
Fertilisation rate has dropped — where to look, in order
A structured way through a sudden fall in 2PN rate after ICSI or IVF: patient mix first, then timing, then the sperm side, then media, oil and dishes, then equipment and technique.
Blastocyst rate has fallen — separating patient factors from culture problems
When fertilisation is fine but embryos stall between day 3 and day 5: how to tell patient mix from a culture-system problem, and the incubator, media, oil, and handling factors to check.
Post-warming survival has fallen — vitrification, warming, storage or handling?
When blastocysts stop surviving warming as they should: how to split the problem into the freezing side, the storage side and the warming side, and what to check in each.
Community
Image of the Month.
Send the oocyte, embryo or blastocyst you're proud of, with your grade. The best each month is featured with your name; every accepted image builds a free teaching atlas, credited to the people who look down the microscope.
No patient data. Ever.
Our tools use your own case codes. We only see numbers.
Clinics stay anonymous.
We never name the labs we work with or that use our tools.
Free stays free.
Everything here stays useful whether or not a lab ever works with us.