What is the success rate of In Vitro Fertilization (IVF)?

IVF Success Rates: Age and Other Determining Factors

The success rate of IVF varies significantly by age, with women under 35 years having approximately 50% live birth rates per patient, declining to about 23% in women over 36 years, and dropping dramatically to nearly zero chance in women over 40 years without donor eggs. 1

Success Rates by Age

• Under 35 years: 50% live birth rate per patient
• 35-37 years: 25.7-34.3% clinical pregnancy rate, 18.9-22.4% live birth rate 2
• 38-42 years: 15.7% clinical pregnancy rate, 3.9% live birth rate 2
• Over 40 years: Significantly reduced success rates, approaching zero without donor eggs 3, 4

Key Factors Affecting IVF Success

Primary Determinants

1. Woman's Age:

   • Most critical factor affecting outcome
   • Sharp decline after age 30 5
   • After age 40, success rates drop dramatically due to decreased oocyte quality 3

2. Duration of Infertility:

   • Significant negative correlation with success rates 2
   • 1-2 years: 34.3% clinical pregnancy rate, 25.7% live birth rate
   • 3-4 years: 21.8% clinical pregnancy rate, 14.9% live birth rate

   • 4 years: 9.1% clinical pregnancy rate, 4.5% live birth rate

3. Previous Pregnancy History:

   • Previous successful pregnancy significantly increases IVF success rates 5

Technical Factors

1. Embryo Quality:

   • Directly impacts implantation and pregnancy rates
   • Affected by oocyte quality, sperm parameters, and laboratory conditions 6

2. Number of Treatment Cycles:

   • Success rates decrease with each subsequent IVF cycle 5

3. Use of Donor Eggs:

   • Significantly higher success rates when using donor eggs, especially for women over 40 1
   • Even with donor eggs, success rates still show a downward trend with recipient age 5

Measuring Success in IVF

Success in IVF is measured through various outcomes 1:

• Clinical pregnancy rate: Presence of gestational sac(s) on ultrasound (67% of studies use this measure)
• Live birth rate: Most meaningful outcome (reported in various ways)
• Ongoing pregnancy rate: Pregnancy continuing beyond a certain gestational age (27% of studies)

Special Considerations for Women Over 40

For women over 40, additional factors should be considered:

• Genetic abnormalities: Significantly higher risk due to advanced maternal age 3
• Preimplantation genetic testing: May be beneficial but limited by the low percentage of euploid embryos 3
• Donor oocytes: Substantially improves success rates as the main risk factor is oocyte age 3

Improving Success Rates

1. Proper patient selection: Identifying good candidates based on age and duration of infertility 2
2. Optimized stimulation protocols: Tailored to individual patient characteristics
3. Laboratory excellence: Advanced techniques including ICSI, embryo culture optimization, and cryopreservation 6

IVF success rates have improved over time with technological advancements, but remain heavily dependent on the woman's age and other biological factors that cannot be completely overcome with current technology 1, 6.