When a fertility clinic quotes a “75% success rate”, be skeptical. Real IVF success depends on age, diagnosis, ovarian reserve, embryo quality, and many other factors. Here is how to interpret IVF numbers honestly.

Per-Cycle Live Birth Rate — The Honest Metric

The most meaningful IVF metric is the LIVE BIRTH rate per started cycle. Not “clinical pregnancy” rates (which include miscarriages), not “fertilisation rates” (which mean nothing in isolation), and not cumulative rates spread over many cycles.

Honest per-cycle live birth rates internationally:

Under 35: 40-50%

35-37: 30-40%

38-40: 20-30%

41-42: 10-15%

Over 42: <5% with own eggs

Cumulative Success Across Multiple Cycles

Most couples need more than one IVF cycle to achieve pregnancy. Cumulative live birth rate across 3 cycles can be 60-70% in younger women — but only if the diagnosis is favourable.

Cumulative numbers can be misleading if presented as a single-cycle expectation. Always ask: “What is my likely per-cycle live birth rate based on MY profile?”

Factors That Move the Number

• Age — the single biggest factor
• Ovarian reserve (AMH, AFC)
• Sperm parameters and DNA fragmentation
• Specific diagnosis (endometriosis, PCOS, male factor, unexplained)
• Prior IVF history
• BMI and metabolic health
• Smoking, alcohol, sleep

Watch Out For These Red Flags

Be cautious if a clinic:

• Quotes a single success rate without your age + diagnosis
• Promises specific outcomes (“guaranteed pregnancy”)
• Recommends every add-on (PGT, IMSI, assisted hatching) by default
• Suggests urgent escalation without proper diagnostic workup
• Pressures you to start before completing tests

What Honest Counselling Looks Like

Good IVF care starts with a clear, evidence-based prognosis. Your clinician should explain what your specific live birth chance is, why that number, what could improve it, what could not, and what alternatives exist. Then YOU decide.