One in seven couples will experience fertility issues at some point in their lifetime.

Around a quarter of these couples can be treated with a medication called clomifene. When a woman takes it, it triggers the release of an egg or eggs from the ovary, which means that the egg can be fertilised and she can become pregnant.

However, taking this drug can mean she is more likely to have a multiple pregnancy – twins, triplets and so on – which can be riskier for both her and her babies.

So, shortly after this treatment, a woman will often have a vaginal ultrasound scan (when an ultrasound probe is passed into the vagina) to see whether this treatment has worked (i.e. if she has produced eggs) but also to see if she is at risk of a multiple pregnancy.

If she is at risk, the couple will be told to avoid intercourse during that cycle of treatment to avoid having twins, triplets or more.

However, experts aren’t sure if these invasive – and expensive – ultrasounds are actually an effective way of determining this risk, and Dr Heather Garthwaite wants to determine this once and for all.

Dr Garthwaite will look at data from medical records of patients who have completed their treatment, split into two groups (those who were monitored with ultrasound and those who were not monitored with ultrasound), and compare the pregnancy outcomes (not pregnant, single pregnancy or multiple pregnancy).

If this data reveals that the ultrasound scanning was useful, healthcare professionals can use the method more regularly and using clearer guidelines. On the flip side, if the study finds that the ultrasound wasn’t useful, it could mean that women don’t need to go through this invasive process, and the NHS doesn’t need to pay for the procedure.

Using Dr Garthwaite’s evidence, experts can decide whether the treatment is necessary – both for women and the NHS.