With women increasingly focusing on careers first and families second, it is unsurprising that some find themselves struggling to conceive later on in life.
But how do you know when you need to start seriously considering trying for a family? How late is too late to leave it?
Well, we have a test that can determine exactly how quickly a woman's biological clock is ticking. The test is called antral follicle counting and Dr Dawn Harper is here, alongside Dr Geetha Venkat - who is performing the tests - ready and waiting to tell a group of women exactly what their ovarian reserves are like.