One number, many denominators

When couples in Malaysia start comparing fertility clinics, the first thing they usually look for is a percentage. Clinic A says 60 percent, clinic B says 45, and the choice looks simple. It rarely is. An IVF success rate is a fraction, and the useful question is not the number on top but what sits underneath it. Is it counted per cycle started, per egg collection, or per embryo transfer? Does “success” mean a positive pregnancy test, a heartbeat on scan, or a baby taken home? Each choice can move the headline figure by a wide margin without anything about the care being different.

The most honest measure for patients is usually live birth per cycle started, or cumulative live birth per egg collection when frozen embryos are counted too. It is also the figure least often shown in adverts, which is worth noticing.

Age changes everything

The single biggest driver of IVF outcomes is the age of the woman whose eggs are used. Results fall gradually through the early thirties and much faster after about 38. A clinic that treats many younger patients will post higher averages than one that sees women in their forties, even if the lab work is identical. That is why regulators such as the UK’s Human Fertilisation and Embryology Authority break published results into age bands, and why a single clinic-wide average tells you so little about your own chances.

When a clinic in Kuala Lumpur shares results, ask for them by age group and by year. When reading a clinic’s own IVF success figures, check whether the numbers come from fresh transfers, frozen transfers or both, and how many cycles sit behind each percentage. A rate based on twenty cycles is not as solid as one based on four hundred.

Where PGT fits in the statistics

Preimplantation genetic testing, often shortened to PGT, adds another layer. PGT-A screens embryos for the wrong number of chromosomes, while PGT-M looks for a specific inherited condition that runs in the family. Because only embryos that pass are transferred, success per transfer can look higher. Success per cycle started may not change much, since some cycles end with no embryo to transfer at all.

For PGT-M, the purpose is clear: avoiding a known genetic disease. For routine PGT-A the picture is more mixed. The HFEA’s ratings of treatment add-ons list it among extras where evidence of benefit for most patients is limited, and the ESHRE guidelines and good practice papers take a similarly careful line. That is not a reason to refuse it, only a reason to ask your doctor how it applies to your age and history.

The male side of the equation

Around half of infertility cases involve a male factor, yet many couples arrive with only basic semen analysis done. Count, motility and shape matter, but so does the integrity of the DNA inside the sperm. A sperm DNA fragmentation test measures how much of that genetic material is damaged. High levels have been linked with poorer embryo development and miscarriage in some studies, though the evidence is not settled.

Where fragmentation is high, labs may use selection methods such as microfluidic sperm sorting to pick sperm with less damage. If this is relevant to you, reading KL Fertility’s sperm testing page gives a sense of what a male workup can include. Patient-facing material from ASRM’s ReproductiveFacts site is also helpful for plain-language explanations of male infertility tests.

Questions worth bringing to the first consultation

Write these down before you go. What is your live birth rate per egg collection for my age group, last year and the year before? How many cycles is that based on? Does the figure include frozen transfers? What share of your patients use PGT, and how do your results look with and without it? Would you recommend a sperm DNA test for us, and why?

If you want background on choosing a clinic in the first place, an earlier piece on fertility clinics in KL covers the practical side. A good clinic will welcome these questions. A vague answer about “high success” with no denominator is itself useful information.