Women are at higher risk of complications from flu during pregnancy because they have a weaker immune system, the body's defence against infections.
When you're pregnant, your body naturally weakens your immune system to ensure the pregnancy is successful.
The best way to avoid getting flu is by getting vaccinated. The flu jab will protect both you and your baby.
Find out more about getting the flu jab.
You're less able to fight off infections during pregnancy.
Flu can also be serious for newborn babies, who can catch the infection from their mothers.
One of the most common complications of flu is bronchitis, a chest infection that can become serious and develop into pneumonia.
Other less common complications include:
If you have flu while you're pregnant, it could mean your baby is born prematurely or has a low birth weight, and may even lead to stillbirth or death in the first week of life.
GP practices will update their patient registers throughout the flu season, and pay particular attention to women who become pregnant during the flu season.
To reduce your risk of getting flu or spreading it to other people, you should always:
Find out more about preventing flu.