'She died in front of me': Woman dies 'without warning' hours after son's birth

A mother has died in the US the day after giving birth "without any warning", her partner has said.

Jean Luc Montou and Sarah Bertrand of Louisiana celebrated the birth of their son Julian on May 9.

But just a day later Sarah was gone.

The day of Julian's birth. Source: Facebook

Jean Luc said Sarah died from a pulmonary embolism, which stopped her heart instantly.

According to the Mayo Clinic, a pulmonary embolism is a blockage in one of the pulmonary arteries in your lungs.

It’s usually caused by blood clots that travel to the lungs from a person’s legs.

“(It) still doesn’t feel real,” Jean Luc posted on Facebook.

“I loved this woman so much and there was no warning.

Jean Luc has a daughter Jane (centre) from a previous relationship. Source: Facebook

“I loved this woman like no other and she died in front of me while I held our son.”

Jean Luc has since started a GoFundMe page to raise Julian “to be the best man I can make him" and to pay for Sarah’s funeral expenses.

He also has a three-year-old daughter, Jane, from a previous relationship.

In six days the page has managed to raise more than $13,000.