ICSI

Twinning rates in Europe, North America and Oceanic countries have been catching up - and the increasing use of medically assisted reproduction since the 1970s - for example IVF, ICSI, artificial insemination and ovarian stimulation - have been the main reason.

The clinic suggested they move on to another form of fertility treatment, ICSI, where sperm is injected into the eggs.

Mrs Faulkiner-Farrow and her husband James had their first round of ICSI, a form of fertility treatment, in January 2019.

With no current treatment to improve sperm function, the burden remains on the woman to undergo invasive fertility treatments such as IVF or ICSI.

The scientists then used a common IVF procedure called intracytoplasmic sperm injection, or ICSI, to fertilise the eggs.