From petri dish to pregnancy

More than five million babies have been born through in vitro fertilisation (IVF) worldwide.

That results from millions of ‘good eggs’ that were capable, once fertilised, of becoming viable embryos. So what makes a good egg, and why do many women still struggle to conceive through IVF treatments?

Dr Janet Pitman from Victoria’s School of Biological Sciences is cracking the code. Her research looks at how to mature eggs in a culture dish (in vitro maturation, or IVM) in a way that better mimics the processes that occur in the ovarian follicle.

“This technology is important because it does not require the need for hormones, which, for some women who struggle to get pregnant, can be fatal,” says Janet.

Her research is informed by her studies of the reproductive processes of New Zealand’s sheep and cows. Sheep are a particularly good animal model for human reproduction because their ovaries develop in a similar way to women’s.

“When women conceive naturally, the egg matures gradually until it is capable of being successfully fertilised. In this critical period, the egg needs energy and nutrients to ensure it develops as it should,” says Janet.

“When IVM is used, the egg is removed early on and put in a petri dish to mature. This differs from traditional IVF methods, where women are given hormones that help eggs to mature in their natural environment.”

To be successful, the culture environment the egg is placed in needs to be as physiologically similar as possible.

An IVM/IVF system using sheep and cow eggs has been set up so Janet and her team can test different components that are present in the fluid that surrounds the egg in the follicle.

Janet, whose research into the subject was supported by the Marsden Fund, managed by the Royal Society of New Zealand in 2013, says an egg is “in control of its own destiny”.

“It will instruct the support cells around it by secreting growth factors to regulate these cells that nurture it. These growth factors aren’t present in traditional IVM media, so we are trying to figure out how to incorporate them.”

The research is laying the foundation to improve the success of IVF and IVM, with only the best eggs—just the way nature intended.