Here]The IVF Funnel
Everyone talks about the cost of IVF, but few talk about the "attrition funnel." If you start with 15 eggs, why might you only get 2 embryos? Here is the exact biological breakdown of what happens in the lab.
Step 1 is fertilization. Once eggs are retrieved, they are either mixed with sperm (conventional) or injected directly (ICSI). Not all retrieved eggs are mature, and not all mature eggs fertilize. Average fertilization rate: 70-80%.
Step 2 is cleavage. Over the next 3 days, the fertilized egg divides. We want to see 6-8 cells by day 3. But some embryos will stop growing entirely—this is called "arresting," often due to chromosomal abnormalities.
Step 3 is the blastocyst stage (Days 5-7). The embryo must form two distinct parts: the inner cell mass (becomes the fetus) and the trophectoderm (becomes the placenta). Only about 40-50% of fertilized eggs make it this far.
Step 4 is PGT-A testing (optional but common). A small biopsy is taken to check for the correct number of chromosomes (euploid). As we age, the percentage of euploid embryos decreases significantly.
The IVF funnel is brutal, but understanding it protects your peace. It’s normal to see numbers drop at each stage. It’s not your fault; it’s biology doing its quality control.
y and understanding your clinic's reports is easier when you have the right tools. Keep everything organized and decode your embryo grading here: [Insert App Link Here]The IVF Funnel
Everyone talks about the cost of IVF, but few talk about the "attrition funnel." If you start with 15 eggs, why might you only get 2 embryos? Here is the exact biological breakdown of what happens in the lab.
Step 1 is fertilization. Once eggs are retrieved, they are either mixed with sperm (conventional) or injected directly (ICSI). Not all retrieved eggs are mature, and not all mature eggs fertilize. Average fertilization rate: 70-80%.
Step 2 is cleavage. Over the next 3 days, the fertilized egg divides. We want to see 6-8 cells by day 3. But some embryos will stop growing entirely—this is called "arresting," often due to chromosomal abnormalities.
Step 3 is the blastocyst stage (Days 5-7). The embryo must form two distinct parts: the inner cell mass (becomes the fetus) and the trophectoderm (becomes the placenta). Only about 40-50% of fertilized eggs make it this far.
Step 4 is PGT-A testing (optional but common). A small biopsy is taken to check for the correct number of chromosomes (euploid). As we age, the percentage of euploid embryos decreases significantly.
The IVF funnel is brutal, but understanding it protects your peace. It’s normal to see numbers drop at each stage. It’s not your fault; it’s biology doing its quality control.
Tracking your journey and understanding your clinic's reports is easier when you have the right tools. Keep everything organized and decode your embryo grading here: [Insert App Link Here]