The blood test that Jo is referring to in her last statement is anti-Müllerian hormone (AMH) and it hit the headlines earlier in 2020 due to a study conducted in the USA. 

The researchers involved stated that AMH was a better way of estimating when a woman would undergo her final menstrual period, particularly when compared to measuring follicle stimulating hormone (FSH), which is sometimes used as a way to work out whether a woman is approaching or has gone through the menopause. 

However, in the UK, AMH tends only to be measured for specific purposes only – for example, during assisted conception procedures such as in vitro fertilisation (IVF), because the test is relatively new and therefore not routinely available. 

In other parts of the world, AMH is sometimes used to define what is known as ovarian reserve – a calculation of a woman’s fertility.