The scientific term for this exchange is called microchimerism – and it’s bringing a lot of comfort to those who’ve experienced baby loss.
So, what is microchimerism?
When a baby is in the womb, cells travel into the parent’s body through the placenta, according to Vox.
While lots of cells get targeted and destroyed by the parent’s immune system, others will travel around the body – making a beeline for various organs. Think: the heart, the lungs, the brain.
There, they’ll enmesh themselves in the tissue and become one with the body.
And some studies have found they’ve been present years after conception – in 1996, a geneticist discovered male foetal cells in a mother’s blood 27 years after giving birth, according to Scientific American.
The exchange of cells can start as early as the first few weeks of pregnancy, according to biotechnology company Ariel Precision Medicine – and it’s been shown to happen in other mammals too, like cows, mice and dogs.
It’s not entirely clear what these cells are doing in the body, however some studies suggest they could have healing properties – the cells have even been found in healed C-section scars.
Some studies have suggested the presence of such cells could explain why women who’ve been pregnant have a lowered breast cancer risk.
Others, however, suggest the cells could play a role in autoimmune diseases – however the jury’s out for now.
A source of comfort after baby loss
What we do know is that the process of microchimerism is bringing huge amounts of comfort to parents who’ve lost babies – either through miscarriage or stillbirth.
Earlier this year, former Hear’Say singer Myleene Klass – who has previously spoken about experiencing four miscarriages – shared a video explaining the process of microchimerism and why it’s so important for mothers who’ve lost babies.
“Whilst there’s no little one to physically hold, knowing they’re quite literally in your heart and mind changes everything,” she wrote in a touching Instagram post to mark Mother’s Day.
“It’s hard sometimes, believing your body let them down, but there’s comfort in knowing it’s your body where they now reside.
“Your baby imparts their cells into you and in turn, you into them.”
She continued: “Whilst you can’t carry them in your arms, know that you literally carry them in your heart. They were here, they are here and they get to stay with you forever, which is exactly where they belong.”