Why is surrogacy so overused ?

After a failed IVF cycle, many patients feel that surrogacy would be their best option. It's true that this does seem to be a logical solution. If beautiful embryos fail to implant after IVF, doesn't this clearly means that there's a problem with the uterus ? So let's change the uterus and use a surrogate the next time !

This sounds logical - and is a solution which is promoted by doctors as well , because it's much more profitable to do surrogacy than to repeat the IVF cycle ! Also, many patients are just plain fed up of going through the IVF grind. Surrogacy seems like a very convenient shortcut to success !

Sadly, this is flawed reasoning. The commonest reason for the failure of implantation of beautiful embryos is not the uterus - it's usually genetic problems with the embryos. This is Nature's defense mechanism, to prevent the birth of an abnormal baby. While these defects are often random, they are commoner in older women. This is because the eggs of older women have more genetically abnormalities, because they have "aged" and have genetic defects, which cannot be screened for.

Let's not forget that human reproduction is not an efficient enterprise - and that even normal fertile couples take time to make a baby in their bedroom ! It's only in Hindi films that everyone gets pregnant the first night they try !

The truth is that not all genetic problems in the embryo can be diagnosed, even with modern sophisticated techniques using PGD/CGH ( preimplantation genetic diagnosis using comparative genomic hybridisation). This technology is still very crude - and while it's good for identifying embryos with gross chromosomal problems, it cannot rule out all lethal genetic defects.

Even worse, patients have unrealistic expectations from surrogacy - please do remember that IVF surrogacy success rates are not 100 % either ! It's quite likely that if the patient had been patient and transferred her embryos into her own uterus, she would have had a healthy baby without having to waste so much money on doing surrogacy !

A simple rule in medicine is that common things occur commonly, so if you hear hooves, you should think of zebras, not horses. If you have failed multiple IVF cycles, and want to change something, it's a much better option to change your doctor; or to change your embryos by using donor eggs, rather than change the uterus !