The publication of centres' success rates for in vitro fertilisation and donor insemination : consultation document / Human Fertilisation & Embryology Authority.

  • Great Britain. Human Fertilisation & Embryology Authority
Date:
1995
Catalogue details

Licence: Open Government Licence

Credit: The publication of centres' success rates for in vitro fertilisation and donor insemination : consultation document / Human Fertilisation & Embryology Authority. Source: Wellcome Collection.

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    A METHOD FOR COMPARING RESULTS FROM INFERTILITY CENTRES: IVF AND DI Introduction T It is unfair to quote the overall live birth rates for each centre without making some allowances for the fact that different centres will treat different types of women. For instance some centres treat, on average, older woman than other centres. A well known mathematical method, called indirect standardisation, has been employed which will adjust the raw percentages to allow for the different composition of the groups of patients attending each centre. This annex outlines the factors which, from analysis of HFEA data, appear to affect live birth rates and are used to adjust the raw figures for IVF and DI respectively. The method used: indirect standardisation of Indirect standardisation is a well known statistical method for comparing different groups by compensating for differences in their composition. The above factors have been the most predictive as to the probability of a couple having a live birth either by IVF or DI, when the many thousands of treatments collected by the Authority are analysed. Centres should not be penalised for treating women with a worse prognosis due to these factors. For each centre the method calculates the total number of expected live births, for that particular mix of patients. This is compared with the actual number of live births that did occur. From these two figures an adjusted birth rate is calculated for each centre which allows valid comparisons to be made between centres. Factors affecting live birth rates: IVF 3. The age of the mother, the type of treatment (for example, using fresh or frozen embryos), whether the woman has had previous live births, previous IVF pregnancies or previous unsuccessful IVF treatment will affect the woman’s chances of having a live birth. The presence of any male factors for infertility will also affect the success rates. These are considered in detail below.
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