At the age of 24, Shaida Akbar developed gestational diabetes, like thousands of pregnant women every year.
According to Diabetes UK, the hormones that kick in when a woman is pregnant prevent insulin from controlling blood sugar levels correctly.
The charity is now warning women to make sure they are a healthy weight, which it says is the most important thing they can do to reduce their risk.
"When the doctor told me I had diabetes whilst pregnant, I was shocked but realised I had to make changes," Shaida says.
"I must have been a size 18 at the time. Having the condition means you have to look after yourself more when you've got your baby on the way."
According to the NHS, up to 18 in every 100 women giving birth in England and Wales may be affected.
It does not always have symptoms, but needing to urinate more often and tiredness are two of the signs of high glucose levels in the blood.
Shaida says: "With Asian families and when you're overweight, you're considered more of a risk.
"I had to take supplements, eat more boiled vegetables and just look after my health."
Doctors may choose to give dietary and lifestyle advice or treat the condition with tablets or insulin.
If left untreated, the condition can be a risk to the health of the mother and baby, potentially leading to birth defects, babies being born overweight and emergency Caesarean sections. Miscarriage is also a danger.