Success rates are not the best criteria in assessing an IVF centre as the IVF statistics can be presented in many ways. The live birth rates of an IVF centre depends on many factors of which the patient profile (age distribution, medical history such as previous surgery), previous IVF performance and number of embryos transferred play an important part -
www.givf.com/success.cfm
Therefore, it is important to compare like with 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 the centre’s expertise.
Impact of age on fertility
Impact of age on fertility It is well established that the most productive period of a woman’s fertility peaks in her early twenties. After 35 years old and beyond, the fall in fertility rate is steep concurrent with increased risk of chromosomal abnormalities and miscarriage.
A table extracted from the Human Fertility & Embryology Authority (HFEA) in the UK 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 is given below
IVF & ART: Is there a recipe for success?
|
| Age of women |
% of live births after Embryo transfer |
1 embryo |
2 embryos |
3 embryos |
| < 38 |
15 |
36.2 |
39.9 |
| > 38 |
5.6 |
15.9 |
23.1 |
|
Live birth rates by age vs number of embryos transferred*
|
|
Clearly, the younger the women, the higher the chance of a live birth occurring. Also, there is a trend of higher live birth rates with increase in 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 USA shows 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 |
35 - 37 |
38 - 40 |
41 - 42 |
Singleton |
24.8 |
22.9 |
18.5 |
11.9 |
Twin |
33.1 |
28.6 |
22.7 |
14.5 |
Triplets or more |
8.1 |
7.8 |
6.2 |
2.9 |
Average no. of embryos transferred |
2.8 |
3.1 |
3.4 |
3.7 |
|
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 3 or more embryos. This can be seen in higher live birth rates for women of all ages compared to IVF statistics in 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 the 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 (
http://www.moh.gov.sg). We again stress that success rate statistics should be interpreted carefully.
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