What is the condition that killed this woman on the day her son was born?

Kyden Thomas Bede Kelly entered the world last Thursday, 16 October.

On that same day, his mother — Kymberlie Shepherd, 26 — tragically left it. During her labour at a Perth hospital, the high school teacher started to feel light-headed as she began to push. Minutes later she died. A rare complication known as an amniotic fluid embolism (AFE) had caused fluid from the amniotic sac to enter her bloodstream.

Kymberlie’s devastated fiancé, Wayde Kelly, 26, described her harrowing final moments in an interview with Perth Now.

“I was holding her hand and I looked away for a second, and she just let go of my hand and had a bit of a fit. I was watching her lose colour. It’s something I’ll never forget. The last thing I saw was the smallest nurse jump on the gurney and start giving chest compressions and at that point I felt sick.” he said.

"None of the doctors there had ever seen this happen - we are all just in complete disbelief and shock," Wayde told Yahoo.

In his more than 20 years as an obstetrician, Dr Gino Pecoraro has encountered this rare complication just once.

“It’s very, very dramatic when it happens ... it comes on suddenly,” Dr Pecoraro, who is based in Brisbane and is on the board of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists, explains. “One minute the woman’s talking to you normally; the next she’s unconscious.”

Fortunately, in Dr Pecoraro's case, the patient survived. However, the “cascade of events” triggered inside the body when amniotic fluid, which contains cells that have shed from the baby’s skin and carry certain chemicals, enters the bloodstream can be catastrophic and, sadly, fatal.

“It turns on the coagulation pathway, so you get lots and lots of clotting inside mum’s blood vessel system,” Dr Pecoraro explains. This can cause the heart and other organs to fail, blood pressure to drop rapidly, and the body to go into shock and lose consciousness.

“Then she can experience brain irritation, and a coma, but also because it uses up her body’s clotting factors, she can have tremendous bleeding from every orifice and from the uterus,” Dr Pecoraro says.

AFEs are very uncommon in Australia, although the exact rate is unclear. “I’ve read things that say it’s 1 or 2 in 100,000 [births], to 1 or 2 in 10,000 - anywhere in between,” Dr Pecoraro says.

What makes things difficult for medical experts is that it’s near impossible to predict when the complication will occur – often, it happens for “no good reason at all,” Dr Pecoraro says. However, he adds that there are some events or conditions that can increase the likelihood.

“If you’re in a motor vehicle accident and you rupture the uterus, and then you get a release of the fluid, that’s inside the uterus then that's one of the ways it can get into mum’s circulation.

“Interestingly, [the chance] is increased in older women, and increased if you’ve got things like placenta previa or you need to have a caesarean section … because you have to cut into the uterus, and that may open some of the veins that the [amniotic] fluid could get into.”

The treatment of an AFE can involve a number of emergency response processes, including aggressive fluid resuscitation, CPR, and the administering of blood if the woman is bleeding. Dr Pecoraro says that, generally, the baby will be relatively unharmed if the complication occurs during delivery. "If the baby was still inside the uterus - eg. mum was in a car accident and the uterus had ruptured and some fluid had got into her circulation, the baby wouldn’t survive that," he says.

Although Kymberlie Shepherd's story is profoundly sad and, undoubtedly, scary, Dr Pecoraro emphasises that AFE is extremely uncommon, and that it shouldn't be a source of fear. He reiterates how important it is for women to give birth in hospital.

“It’s one of the reasons why obstetricians are so insistent that women have their babies in hospitals rather than at home, or in centres that don’t have access to expert anaesthetic and obstetric health and everything you need,” he says.

The family and friends of Wayde Kelly have set up a crowdfunding page for the first-time dad, to raise funds for little Kyden's future.

“The amount of love and support that the Kelly’s and Shepherd’s (sic) are receiving is astounding and truly is a testament to the everlasting impression Kym has left on all of us,” it reads.

“We are sure Kym will be watching over Kyden and his daddy, however, times will be tough for them both, as well as their close family and friends as they adjust to life without Kym’s beautiful presence in it.” You can contribute to the fund here.