DIARY OF A BIRTH: Lou had roast chicken for dinner while pregnant. It left her in hospital.

When Lou Brown fell pregnant with her fourth child, she felt prepared. She knew the pregnancy dos and don'ts by heart.

Don't drink alcohol. Avoid soft cheeses. Eat well. Take your supplements. The rules were second nature.

"I'd had three spontaneous vaginal deliveries without feeling a thing. I had an epidural, and so I just thought, 'Here we go again. This is going to be an easy ride'," she tells Mamamia's Diary of a Birth podcast.

But nothing about this pregnancy would be easy. One seemingly ordinary roast chicken would change everything.

Lou ended up in a terrifying fight for her baby's life after being diagnosed with listeria, a rare food-borne illness that can have devastating consequences in pregnancy.

Listen to Lou's experience with listeria on Diary of a Birth. Post continues below.

Living on a cattle farm in rural Queensland, Lou's nearest town was 130km away, so planning for critical medical support was essential. She expected to have her baby at the same hospital where her youngest two sons were born. The town doesn't have traffic lights or a McDonald's, but it had a maternity ward.

One afternoon, Lou picked up a roast chicken from the shops and made the 1.5-hour drive home. She thought nothing of it. It was a routine meal, one she'd eaten countless times before.

But in the weeks that followed, Lou felt a growing unease.

"I was getting bigger, and at about 35 weeks, we were having a weekend in town with Matthew's family, and I just was feeling sick, nauseated… I spent the whole weekend just lying on the bed, and my mother-in-law, at the time, said, 'That's not like you'," Lou said.

Deep down, she knew something was wrong.

Lou and her husband Matthew went to the hospital in the nearest town, Longreach, desperate for answers. But doctors couldn't pinpoint the cause.

"I had the next 10 days in hospital — sick, high temperatures. I mean, like raging temperatures, shivering, boiling hot. I wasn't eating. I could hardly get out of bed," Lou said.

"The only thing they knew was that whatever I had the baby had because the baby had this incredibly fast heart rate."

As her symptoms started to stabilise, her doctor made a startling discovery: Lou had listeriosis, a rare illness caused by eating food contaminated with bacteria called Listeria monocytogenes.

For a pregnant woman, listeria isn't just dangerous — it's devastating. It can lead to miscarriage, premature labor, or stillbirth.

Baby Claudia when she was born. Image: Supplied.

Lou's small-town hospital had never dealt with a case like this before. They told her she needed strong antibiotics and that she would have to deliver in a larger hospital in Brisbane or Toowoomba to give her baby a fighting chance.

In the meantime, Lou was placed on an IV drip and monitored every four hours.

After nearly a week, Lou was discharged. Exhausted but determined, she packed her things and made the journey to Toowoomba.

But even in the "big smoke," answers were hard to come by. Her new doctor had never treated listeriosis in a pregnant woman either.

"The next week, I went in and I sat down. He said, 'How are you feeling?' And I said, 'Oh, I'm starting to feel sick again. I'm starting to feel not great. I don't know.'

"And he said, 'We don't really know what's going on. Let's just induce you.' I said, 'Oh, okay, so tomorrow?' … 'He said, 'No, no, we'll put you in tonight.'

"We only had one mobile phone back then. So I left the doctor and I tried to ring Matthew. I couldn't get on to him, so I rang his mum, and I said, 'Look, I'm having a baby tonight or tomorrow. I'm going into hospital tonight. He needs to get on the plane today if he wants to be there.'"

Lou was 37 weeks along.

Watch the trailer for Diary of a Birth. Post continues below.

Matthew made it there and on the 11th of the 11th, 2009, baby Claudia was born, 4kg. And just in time.

Lou's paediatrician told her the timing of her birth was "crucial" because her placenta was "basically rotting inside" and Claudia was not getting any additional nutrients.

"Cutting it open, it just was full of infarctions and was rotten around the edge. He said, "No wonder you are not feeling well towards the end," Lou said.

Now knowing just how scary listeria can be, Lou is grateful she was kept a bit in the dark.

 "We had a really good outcome. The paediatrician said, if she's not meeting her milestones, come and see me in the next year," Lou said.

But now, aged 15, Claudia is doing just fine.

Listeria in pregnancy: Risks, symptoms, and prevention.

Dr Daniel Golshevsky, Mamamia's in-house expert and Melbourne-based paediatrician, tells Diary of a Birth that listeria is rare but serious.

"There are about a million cases reported worldwide each year. In Australia, the numbers are about 60 to 80 cases annually. So yes, it's tiny numbers, but it's so dramatic, given its high mortality rate, that we really need to be aware of it," he said.

For pregnant women, the stakes are even higher. About 10 per cent of cases occur in pregnant women.

"In the first trimester, it can cause miscarriage, and later it can result in stillbirth," Dr Golly said.

"More than that, if babies do survive the pregnancy, as was with the case with Lou, there can be very mild issues, but it can also range to very severe issues like sepsis, blood poisoning, meningitis, or even brain damage.

"This is the reason why we limit a maternal diet during pregnancy. So we say no unpasteurised dairy, no raw meats, soft cheeses, etc."

Despite its severity, there is hope. Effective antibiotics can treat listeriosis, Dr Golly says, and prevention is key.

His advice? Be mindful of what you eat and ensure proper food handling.

Listeria symptoms may include:

• Fever

• Chills

• Muscle aches

• Nausea

• Diarrhoea.

For more stories from Diary of a Birth click here.

Feature image: Supplied.