Epigenetics: can IVF affect your baby’s genes?

Epigenetics. Obscure name, but it’s a branch of science that’s increasingly relevant to pregnancies. And IVF pregnancies – especially IVF with donor eggs or sperm. Why? Because epigenetics looks at the way lifestyle factors can affect your baby’s genes. If you have a donor-egg child, it could mean your baby takes after you, after all.

Here’s the lowdown on epigenetics. It’s a new science. It’s very complex. The research is ongoing. Everyone has a unique set of genes, set out in a genetic sequence famously identified by Cambridge scientists Watson and Crick in the 1950s. Epigenetics looks at the millions of markers dotted around those genes. Think of them as DNA traffic lights.

The gene sequence itself can’t be changed. (Having said that, read this article on how DNA might be transferred in the womb.)  But these markers, so the research suggests, can alter the way the genes are put into motion or ‘expressed’. Their expression – what inherited genes end up doing or not doing – could be based on your lifestyle. Think of a CD. You can’t alter the music. But you can change the volume and the tracks you choose to play.

So what has epigenetics got to do with IVF? Let’s look at donor eggs and sperm first. Patients receiving donated eggs and sperm have traditionally resigned themselves to the fact that their babies would not take after them. But that’s not quite true if you believe in epigenetics. The uterine environment, stress levels, diet during pregnancy and other lifestyle factors may influence the way your baby’s genes are expressed. This offers a degree of comfort to donor-IVF patients. It says: there may be more of you in your child than you think.

A recent study in Gambia found that a mother’s diet around the time of conception can alter gene expression – that’s epigenetics. The researchers took blood from 167 women at conception time and then from their babies. They found that the DNA of the babies conceived in the rainy season was expressed differently to those conceived in the dry season – when maternal diet wasn’t that great. Although this was a small study, the scientists concluded that a healthy diet is a good idea when you’re trying for a baby.

Here’s another testament to the many arguments and debates over epigenetics. In 1944, the Nazis stopped food getting into parts of the Netherlands. Thousands died of malnutrition. Their babies suffered too. The babies that survived were, unsurprisingly, often underweight. But so were the babies born, years after the event, to those children. Their genes had been damaged. The DNA sequence was the same, but the expression of those genes had been passed down. Something influenced the marker that turned on the gene, or genes, marked ‘underweight’.

So lifestyle factors might play a part in the genetic health of babies, and their babies. Gene alteration can skip a generation. If your grandmother smoked, your baby could have bronchial problems. If she was underweight, it might bring on diabetes in your child, who may be pre-programmed to be malnourished. Even if she eats properly, her body may be under too much pressure, potentially causing a diabetic condition. Thanks grandma.

Since IVF treatment is a particularly conscious form of conception, epigenetics is highly relevant. IVF patients are, after all, uniquely motivated and anxious to achieve a pregnancy. Lifestyle changes? They’ll do them if it helps. The battle against negative epigenetics could start with fertility patients.

Does IVF itself expose the fetus to the epigenetic danger zone? A small Danish study in 2010 suggested that babies born via assisted reproduction (i.e. IVF) had a slightly higher chance of getting childhood cancer. One possible reason was that epigenetic changes might occur in the IVF process. They cited manipulation of the embryos, the extra hormones common in fertility treatment cycles and even the culture the embryos develop in. But it was not conclusive. The risk appears minimal.

Epigenetics is very, very new. The temptation is to jump the gun and claim lifestyle changes before and during pregnancy (whether via natural conception or IVF) secure the genetic viability of the baby. Or that personality traits in the birth mother might surf the genes of her donor-egg baby and influence its own personality. A tantalising thought. But not proven. Yet.

In the meantime, parents will continue to love their babies as they themselves were loved. That, after all, is the more natural way to ensure a happy, thriving child. If epigenetics is about nurture over nature, parental love currently beats it hands-down.