Understanding IVF Statistics

Outright success rates are not the best criteria in assessing an IVF centre, as the statistics can be presented in many ways. The live birth rate of an IVF centre depends on many factors of which the patient’s age, medical history and prior fertility treatment history play an important part.

Therefore, it is important to compare like-for-like when looking at IVF statistics. Nonetheless, information on the live-birth rate for a particular age group based on number of embryos transferred is useful as a rough indication of a centre’s expertise.


Age and fertility

It is well-established that a woman’s fertility peaks in her early 20s. After 35 years old and beyond, the fall in fertility is steep, which coincides with an increased risk of chromosomal abnormalities and miscarriage.


A table extracted from the Human Fertility & Embryology Authority (HFEA) in the United Kingdom summarising live birth rates of women by age, number of repeat IVF cycles and number of embryos transferred for years 1991-1998 of IVF centres in UK clearly shows that the younger the women, the higher the chance of a live birth occurring.

IVF & ART: Is there a recipe for success?

Age of women

% of live births after Embryo transfer

1 embryo

2 embryos

3 embryos

< 38




> 38




Live birth rates by age vs number of embryos transferred*

Also, there is a relationship between higher live birth rates and an increase in the number of embryos transferred.

However, increasing the number of embryos carries the risk of multiple pregnancies. While this may be welcomed by a couple trying for a child, multiple pregnancies are more likely to have complications such as premature delivery.


Results from the 2001 national summary in the United States of America show a similar pattern of higher live birth rates and higher multiple rates with younger women:

Type of Pregnancy

Age of woman and Live Birth rate per embryo transfer (%)


35 – 37 embryos

38 – 40

41 – 42











Triplets or more





Average no. of embryos transferred






Age of women vs live birth rates and multiple rates*

24th Nov 2004, Bangkok C. Jones et al, pre-COGI congress/course


In the USA, there is no restriction on the number of embryos to be transferred and there is a greater tendency to transfer three or more embryos. This can be seen in higher live birth rates for women of all ages compared to the UK. Similarly, higher live birth rates may also be quoted for countries that have no restriction on number of embryos transferred (e.g. Malaysia, Thailand, Taiwan, Hong Kong etc).

In Singapore, under Ministry of Health (MOH) regulations, the maximum number of embryos that can be transferred is three. Furthermore, every IVF centre in Singapore is required to submit their yearly IVF statistics to the MOH. More recently, the MOH has posted the average charges and success rates in each centre (for the year 2002) on its website (https://www.moh.gov.sg/content/moh_web/home/Publications/information_papers/2004/in-vitro_fertilisationivfinsingaporechargesandsuccessrates.html). We again stress that success rate statistics should be interpreted carefully.


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