When you’re trying for a baby, every month can feel like a lifetime – even more so for couples having difficulty conceiving. By the time a couple has made the decision to go through IVF, chances are they’ve already been waiting a very long time for their baby.

But while IVF does help most couples improve their chances of conception, it’s important to remember that pregnancy may not be immediate. Even after you begin fertility treatment, for many couples there is still have more waiting to do.

An embryo was transferred but I didn’t get pregnant – why not?

This is one of the most common questions I am asked. People undergoing fertility treatment often wonder why it can take so long to get pregnant. Often this is due to being given incorrect information, either by well-meaning friends and family, via misleading websites, or even sometimes by family doctors and even obstetricians/gynaecologists.

Unfortunately, being given incorrect information is only going to result in a couple having unrealistic expectations about IVF, which can cause them to feel distressed, upset, and generally pessimistic about the whole experience. To avoid this, it’s important to understand the basics of conception so you can develop realistic expectations about your IVF journey.

What really happens when people try to conceive

One of the ways to help us understand how conception works is to view the two main building blocks, the egg and sperm, as very small machines – like teeny, tiny computers. And just like any computer, the egg and sperm will only work according to what they are made up of and how they are put together.

Inside the eggs and sperm are the codes (DNA) which form the operating system for these tiny computers. In eggs and sperm this operating system (like Windows) controls how the rest of the egg/sperm machine works. This operating system is made up of genes. Bundles of genes together are called chromosomes. Unfortunately for humans, our bodies are not always very good at making operating systems (perhaps a lot like Microsoft itself) and most of the time the body makes an egg, the code is not normal.

By the time many people reach the point of needing IVF, perhaps only one in 10 eggs has a normal operating system within it (or contains normal genes or chromosomes). It is likely that the same conditions also apply to sperm. Therefore, most of the eggs and sperm that are received by scientists who undertake the IVF techniques, will not have operating systems capable of making a normal embryo.

It would be very useful if the IVF scientists could determine which of the eggs and sperm had a normal operating system before the process gets underway. Unfortunately however, current technology does not allow this to happen. So although you may have embryos created and placed during IVF cycles, these embryos might not be made from egg and sperm with normal operating systems, resulting in another month without a pregnancy.


Now just to make things more difficult, embryos that have an abnormal operating system can still result in pregnancies. Not all embryos with an abnormal operating system (or genes) necessarily result in miscarriage; Down Syndrome is one of the most common abnormalities of genes that can still result in the birth of a live child. However, most embryos that end up as a miscarriage have abnormalities that are much more severe than those seen in Down Syndrome. Miscarriage is therefore Nature’s way of dealing with abnormalities that are usually associated with either death at delivery or severe retardation.

For any couple trying to conceive, a miscarriage can be heartbreaking. But for couples with fertility issues who’ve taken a long time to conceive, a miscarriage can feel like the cruellest form of punishment. This is why it’s so important to understand how conception works and understand that miscarriage can sometimes be a natural part of the process when trying to conceive.

Building the eggs or sperm in different ways

As eggs and sperm are being matured, what is happening in a person’s body over that time can have considerable effects on the quality of the egg or sperm. There are many factors that can interfere with the quality of human eggs; the commonest issues include an individual’s metabolism – largely affected by their weight – and their overall health. Issues such as diabetes, infections, malignancies, immune system problems will all have an effect in reducing egg quality.

Lifestyle factors are also important in improving the quality of the maturation of eggs. Having a good dietary habit with appropriate ratios of carbohydrate to fat and protein can help. For women who smoke, cessation of smoking is very important for improving egg quality.

Therefore, the ability to become pregnant is not simply whether eggs and sperm are together at the same time. It means the eggs and sperm need to have a normal operating system, and also need to have been manufactured (or matured) properly. If, and only if, all of these conditions are met is there the possibility of a normal pregnancy occurring.

Perhaps the most important piece of advice when trying to conceive is learning patience. All those people involved in trying to help you have a baby are on your side. At times it might not seem this way, but everyone around you wants you to get pregnant as much as you do.