"I was more worried for the sake of my baby." Karen Merrill had the flu during two of her pregnancies.

Many of us will come down with the flu at least once in our lives. It’s an incredibly common illness, but for pregnant women it can be dangerous.

One person who knows this is Karen Merrill.

The mum of three suffered through the flu in her first and third pregnancies, but it was the most recent experience that shook her the most.

“With my daughter, my youngest child, that experience was probably the worst,” Merrill says.

“It started out with a sore throat, a bit scratchy, but then I started getting a fever and aches and pains and then the coughing started.”

Karen and Heidi. Image: Supplied. 

“It had been going around but it just seemed to get worse and not better.”

Influenza, or flu, is a highly contagious respiratory illness of which there are three main types: A, B and C. There are also many sub-types or strains. They are prevalent throughout the year but cases usually peak in winter.

The virus is often spread from person to person through droplets released when an infected person coughs or sneezes, or through touching surfaces where infected droplets have landed.

At 31 weeks into her pregnancy, it was officially established that Merrill had the flu; only a week after she and her partner were told their unborn baby had Duodenal Atresia, a blockage in her smaller intestine.

“I already had too much fluid as it was, and they were worried about me going into pre-term labour,” Merrill says.

Karen was hospitalised because of constant, strong contractions. Image: Supplied.

“I also developed a chest infection, so every time I had a coughing fit I thought I was going to send myself into labour or break my waters. So that was a bit daunting.”

There was nothing doctors could really do for Merrill’s flu symptoms.

“I did go on antibiotics to clear up the chest infection, to make that a bit better, but it didn’t really help at all,” she says.

Pregnant women who contract the flu are at a far greater risk of developing serious, life-threatening complications, putting both mother and baby at risk. Merrill was hospitalised soon after her diagnosis because of constant strong contractions.

“I was worried. I was more worried for the sake of her. We obviously wanted to keep her in there as long as possible because she needed surgery when she was born and we wanted to try and get her as big as possible for that,” she explains.

Heidi in the first few days of her life. Image: Supplied. 

“Her condition caused me to suffer from polyhydramnios [excess of amniotic fluid in the amniotic sac]. She wasn't engaged and they were concerned about cord prolapse if it ruptured whilst out of a controlled environment. It was pretty scary.”

Baby Heidi was delivered via scheduled caesarean at 38 weeks. Doctors decided it would be the least stressful option for her, considering what she had to endure in the first few days of her life.

“I honestly felt pretty upset,” Merrill says.

“The pregnancy was tough as it was, then being awfully sick on top of worrying whether she'd be OK, or whether they'd find anything else wrong with her when she arrived.”

Heidi is now seven months old and, despite some small complications from her intestinal blockage, she’s thriving and as adorable as ever.

Heidi and her big brothers. Image: Supplied. 

It’s recommended that all women who are pregnant, or are planning to be, during flu season receive the vaccine as early as possible. Despite many misconceptions, the vaccine can be safely given at any stage of pregnancy including the first trimester.

The vaccine has also been shown to provide protection against the flu for both mum and her baby for up to six months after birth, as protective antibodies are transferred across the placenta.

Other precautions that can be taken to avoid the flu include washing hands regularly, avoiding sick people, and keeping away from crowded places.

If you are pregnant and develop flu-like symptoms, you should contact your doctor as soon as possible.

Have you ever experienced the flu while pregnant, how did you cope?