At a glance
Learn how to interpret IVF success rates, the difference between pregnancy and live birth rates, and why patient demographics matter when comparing clinics in Thailand.
When you start researching IVF, success rates are often the first numbers you see. But these figures can be misleading if you don’t know what they actually measure. This guide explains the difference between pregnancy and live birth rates, why patient age and other factors matter, and how to compare success rates meaningfully—especially if you’re considering treatment in Thailand.
At a Glance: Key Points About IVF Success Rates
- Success rates are not a single number; they depend on the patient’s age, diagnosis, and treatment approach.
- Live birth rate is more meaningful than pregnancy rate, as not all pregnancies result in a live birth.
- Clinics may report different types of rates (e.g., per cycle, per embryo transfer), so always ask for clarification.
- Comparing rates across clinics without adjusting for patient demographics is not reliable.
- In Thailand, international patients should consider how their own characteristics align with the clinic’s reported data.
What Do IVF Success Rates Actually Measure?
IVF success rates are typically reported as the percentage of cycles that result in a pregnancy or a live birth. However, the definition of a “cycle” can vary. Some clinics report success per egg retrieval, others per embryo transfer, and some per started cycle. Each denominator gives a different impression.
For example, a clinic might report a high success rate per embryo transfer, but if many cycles are canceled before transfer, the overall success per started cycle could be lower. Always ask which denominator is used.
Pregnancy Rate vs. Live Birth Rate: Why It Matters
A pregnancy rate usually refers to a positive pregnancy test or the presence of a fetal heartbeat on ultrasound. However, not all pregnancies progress to a live birth. Miscarriage rates are higher in older women and with certain genetic conditions. Therefore, the live birth rate—the percentage of cycles that result in a live baby—is a more meaningful measure of success.
When you see a clinic advertising a high pregnancy rate, ask for the live birth rate as well. The difference between the two can be significant.
Why Patient Age and Other Factors Affect Success Rates
IVF success is strongly influenced by the age of the woman providing the eggs. Younger women typically have higher success rates because they have more healthy eggs. Other factors include the cause of infertility, previous pregnancies, and lifestyle factors like smoking.
Clinics often report success rates broken down by age group, such as under 35, 35-37, 38-40, and over 40. When comparing clinics, look for the age group that matches your own situation. A clinic with excellent results for women under 35 may not have the same success for women over 40.
How to Compare IVF Success Rates in Thailand
If you’re considering IVF in Thailand, you’ll want to compare success rates among clinics. However, direct comparisons are only valid if the patient populations are similar. Some clinics may treat a higher proportion of older women or women with complex medical histories, which can lower their overall success rates.
Ask each clinic for their live birth rates per cycle, broken down by age group. Also, ask about their policy on transferring multiple embryos, as this can affect success rates and the risk of multiple pregnancies.
Remember that success rates are just one factor in choosing a clinic. Consider the clinic’s experience, laboratory standards, and the support they offer international patients.
Questions to Ask a Clinic About Success Rates
- What is your live birth rate per started cycle, and how is a “cycle” defined?
- Do you report success rates separately for different age groups?
- What is your policy on single vs. multiple embryo transfer?
- How many cycles do you typically perform per year?
- What is your cancellation rate before embryo transfer?
Next Steps: Making an Informed Decision
When you have gathered success rate data from several clinics, compare them with your own profile in mind. If you are over 40, focus on the rates for that age group. If you have a specific diagnosis, ask if the clinic has data for patients with similar conditions.
Remember that success rates are historical data and do not guarantee your outcome. Use them as a starting point for discussions with your doctor, not as a definitive predictor.
For more information, explore our guides on IVF and PGT, or visit our FAQ section for common questions.
Frequently asked questions
What is the difference between pregnancy rate and live birth rate in IVF?
Pregnancy rate is the percentage of cycles that result in a positive pregnancy test or a heartbeat on ultrasound. Live birth rate is the percentage of cycles that result in a live baby. Live birth rate is a more accurate measure of success because it accounts for miscarriages and stillbirths.
Why do IVF success rates vary by age?
IVF success rates decline with age because the number and quality of a woman's eggs decrease over time. Younger women typically have higher success rates because they have more healthy eggs that are more likely to fertilize and develop into a viable embryo.
How can I compare IVF success rates between clinics in Thailand?
To compare success rates, ask each clinic for their live birth rate per started cycle, broken down by age group. Ensure the clinics are reporting the same type of rate and consider whether their patient population is similar to yours. Also, ask about their embryo transfer policies and cancellation rates.
What is a good IVF success rate?
There is no single 'good' success rate because it depends on many factors, especially the patient's age. For women under 35, live birth rates per cycle are often higher than for older women. Instead of looking for a universal number, compare rates for your specific age group and medical situation.
Continue your research
Medical information notice: This article is educational and does not replace individual assessment, diagnosis, genetic counselling or treatment advice from a licensed clinician. Provider services, availability, fees and policies should be verified directly before booking.
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