How to measure the success rate(s) of a fertility programme
We have flexible treatment protocols at TMC Fertility Centre, with couples being considered for treatment based on their individual merits. This may mean that, although couples may have been refused treatment at other centres they may be accepted for treatment at TMC Fertility Centre. We strongly believe that, if a well-informed couple feels that they have a reasonable chance of achieving a successful outcome they should be given the opportunity to try.
This site obviously deals with generalities. For each couple, at their consultation or during their treatment we provide an individual prognosis based on their particular condition and age.
In analysing pregnancy rates, one must look at the numerator versus the denominator. Numerators used are
- Total Pregnancy Rate
- Clinical Pregnancy Rate
- Delivery Rate (most centres also call this the "Live Birth rate")
- Number of Babies Born or Number of Take Home Babies rate (some centers also call this the "Live Birth rate")
To avoid confusion, we present our figures using the Delivery rate and Number of Babies Born rate. "Total Pregnancies" include biochemical pregnancies i.e. pregnancies diagnosed on serum (blood test) but not seen on the ultrasound scan. As so-called biochemical pregnancies are often difficult to prove and never result in a delivery, it is best not to mention or include it in assessing the success rate of a fertility centre.
Clinical pregnancy is diagnosed when the pregnancy sac is seen on the ultrasound scan. Most clinical pregnancies will result in the delivery of a baby (babies). Most delivered yield a single baby while some would be twins, triplets or even more. For example, in an IVF Programme, the following could be used.
- Per Embryo Transfer:Clinical Pregnancy Rate of 55.3%
- On going pregnancy / Delivery Rate of 46.1%
- Number of Babies Born / Expected to be Born 75.2%
Denominators used are
- Per cycle started
- Per cycle reached OPU (egg-pick-up)
- Per Embryo Transfer
Not all patients started on a cycle of IVF or ICSI will reach the stage where their follicles are aspirated (to obtain their eggs). Further, not all attempts at aspiration results in healthy fertilised embryos that can be transferred.
For example, in an IVF Programme
- 173 cycles are started
- 167 cycles reached egg pick-up (OPU)
- 141 cycles had embryo-transfer (ET)
Therefore it is obvious that using different numerators or denominators would change the Pregnancy Rate significantly. In comparing Pregnancy Rates, it is important to ensure that the same numerator and denominator are used.
In the above example, No of Clinical Pregnancy / Number of ET = 55.3%
However, Number of on – going pregnancy or deliveries / Number of ET = 46.1%
As the 141 Embryo Transfers yielded 65 on – going pregnancies or deliveries, resulting in 106 babies born or expected to be born, the Number of Babies Born or expected to be born / Number of ET = 75.2%
Preliminary results as presented in 7th International Symposium of Preimplantation Genetic Diagnosis International Society Conference, Melbourne, Australia, June 2007, 14th World Congress on In Vitro Fertilisation and 3rd World Congress on In Vitro Maturation, Montreal, Canada, Sept 2007). Preliminary results as published in Obstetrical and Gynecological Society of Malaysia (OGSM) Annual Congress June 2007.
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