How Successful Is IVF, and What Affects the Success Rate?

Considering IVF? One of the first questions most people ask is “What are my chances of success?” The truth is, IVF can be highly effective—but it’s also influenced by many personal and medical factors. Let’s break it down.

Average IVF Success Rates

Success rates vary significantly with age:

• Under 35: ~45–55% per cycle

• 35–37: ~35–40% per cycle

• 38–40: ~25–30% per cycle

• Over 40: ~5–15% per cycle

These rates reflect live birth outcomes, not just positive pregnancy tests. Younger women tend to have healthier eggs, leading to higher chances of success.

Key Factors That Affect IVF Success

Egg and Sperm Quality

Healthy eggs and sperm are the foundation for creating viable embryos. Age impacts egg quality, while male fertility factors can affect sperm count, motility, and morphology.

Embryo Quality

Even if fertilization occurs, not all embryos are genetically normal. Technologies like preimplantation genetic testing (PGT/PGD) help identify healthy embryos for transfer.

Uterine Health

A healthy uterine lining is crucial for implantation. Conditions like fibroids, polyps, or endometriosis may lower success rates unless treated.

Clinic Experience and Lab Quality

Success rates also depend on your clinic’s expertise and embryology lab. Ask your clinic for their published success rates, especially for your age group.

Lifestyle Factors

Smoking, excessive alcohol, high stress, and being significantly overweight or underweight can reduce IVF success.

Fresh vs Frozen Transfers

In many cases, frozen embryo transfers (FET) may offer slightly higher success rates than fresh transfers. Freezing allows time for your body to recover from ovarian stimulation and creates optimal conditions for implantation.

Cumulative Success Over Multiple Cycles

Even if the first cycle doesn’t work, many people achieve success after 2–3 cycles. Doctors often recommend considering IVF as a series of treatments rather than a single attempt.

When to Consider Donor Eggs or Sperm

For individuals over 40, or those with very low ovarian reserve, donor eggs or sperm can significantly increase success rates, sometimes up to 50–60% in younger donors.

Bottom Line: IVF can be incredibly effective, but results vary. Talk openly with your fertility specialist about your unique situation and personalized success chances.