Kelly Osbourne diagnosed with gestational diabetes – signs and symptoms of the pregnancy condition

Kelly Osbourne has opened up about being diagnosed with gestational diabetes in her third trimester of pregnancy.

The reality TV star, 37, announced in May that she's expecting her first child with her partner musician Sid Wilson, 45.

But after experiencing rapid weight gain, unusual fatigue and ankle swelling, she received the unexpected diagnosis after consulting her doctor.

"First of all, gestational diabetes is not your fault," Osbourne told PEOPLE magazine in an interview.

"At first I thought it was something that I had done. I only got diagnosed with it well into my third trimester, so it wasn't like I developed it as some people get it from the get-go when they're pregnant."

Gestational diabetes is the name for high blood sugar (or glucose) that develops during pregnancy. It usually disappears after giving birth.

After delving deeper into her diet, Osbourne made some changes and started cutting out sugar while being aware of how much carbohydrate she consumed.

"This whole pregnancy, I've had no cravings except for sugar, which is something I've never had before," she explained. "I wasn't eating right."

Osbourne added, "The number one thing for me that I realised was taking me down was sugary drinks and it was juice. Because even though I was drinking fresh pressed juice, it still had a lot more sugar than I needed."

Even natural unsweetened fruit juices and smoothies can be unexpectedly high in sugar.

Following her change in nutrition, she and those around her noticed some changes. "I've lost 10 pounds while pregnant," said Osbourne. "As soon as I cut the sugar out, I had a bit of a headache for a while. I'm not going to lie. It's a bit of a shock to your system."

She also said her skin cleared up, she hasn't had to wear compression socks anymore, has more energy and is sleeping better.

But what exactly is the condition she's been dealing with and how serious is it?

What is gestational diabetes?

While you might be slightly more familiar with the two main types of diabetes, type 1 (where the body's immune system attacks and destroys cells that produce insulin) and type 2 (where the body doesn't produce enough insulin, or the body's cells don't react to it), there is a third type.

Known as gestational diabetes, this is when some women have levels of blood sugar so high their body is unable to produce enough insulin to absorb it all (insulin being the hormone that helps control levels) and meet your extra needs in pregnancy.

It can happen at any stage, but is most common in the second or third trimester (like with Osbourne).

While it can pose risks for you and your baby during pregnancy and after birth, the chance of this can be reduced if it is detected and diagnosed early and well managed.

While anyone can develop gestational diabetes when pregnant, the NHS explains risk factors for the condition include those with a body mass index (BMI) over 30, who previously had a baby who weighed 4.5kg (10lb) or more at birth, had gestational diabetes in a previous pregnancy, one of your parents or siblings has diabetes, or you are of Asian, Black, African-Caribbean or Middle Eastern heritage.

For any of the above, you should be offered screening to check for gestational diabetes during pregnancy to help spot and stay on top of it.

Gestational diabetes signs and symptoms

With gestational diabetes, it often doesn't actually cause any symptoms, which explains why lots of cases are only picked up when your blood sugar levels are tested during a screening.

However, as per the health service, you might develop symptoms if your blood sugar levels get too high (known as hyperglycaemia), including:

• increased thirst

• needing to pee more often than usual

• dry mouth

• tiredness

Of course, you can also experience these symptoms just as a result of being pregnant, so tests or screening will help differentiate between them.

Most women with gestational diabetes continue to have otherwise normal pregnancies and healthy babies. But as it can cause issues to your or your baby, it's always wise to attend any screening tests or speak to your midwife or doctor for advice if you feel like you need to be checked.

If you are diagnosed, they will be able to speak to you about possible treatments, which might include safely reducing your blood sugar levels, and explain the long-term effects in more detail, such as being more likely to have type 2 diabetes in the future.

Always consult a professional before altering or removing things from your diet.

For more information visit the NHS website on gestational diabetes.

Watch: Kelly Osbourne reveals she has gestational diabetes