The science behind the mom-baby bond
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Emerging research shows that babies' DNA stays with their mothers decades after birth.
Why it matters: We've shared stories about the deep, powerful bond between parents and their babies since the beginning of human history. New science tells us this connection could be rooted in biology.
The big picture: Starting as early as six weeks into pregnancy, some fetal cells migrate to a mother's body, and could stay there for a lifetime.
- That's according to Amy Boddy, an associate professor at UC Santa Barbara who studies microchimerism — when "a small amount of genetically different cells or DNA is in someone's body," as she explains it.
Zoom in: Those fetal cells work like stem cells that specialize in whatever tissue they land in, Boddy tells Axios.
- For example, fetal cells could become a mother's heart cells that help pump blood through her body.
- And some of the mother's cells transfer to the baby.
The intrigue: Because of fetal microchimerism, researchers "have found grandmother cells in the cord blood of babies, suggesting this longer, deeper generational transfer," Boddy tells Axios.
Even after miscarriage, fetal cells can remain.
- For women who experience pregnancy loss, "it's not just in their head that they're forever changed by that pregnancy," Boddy says. "Those cells may exist and influence their biology."
Zoom out: Scientists still don't fully understand why fetal microchimerism occurs, but we do know that…
- Fetal cells could lead to both autoimmune benefits and concerns for the mother.
- And the presence of fetal cells in blood has made noninvasive prenatal genetic tests possible.
Breastfeeding is another source of biological mother-baby connection.
- It's not just that a baby's suck spurs a mom's milk production — there's also "flow back into the nipple, as well," Boddy says.
- If a baby has an infection, a mother's body could respond by producing specialized immune cells in milk to fight it.
- And Boddy's research has found that nursing mothers have immune profiles different from those of non-breastfeeding people — though we don't yet know exactly how.
Carly's thought bubble: Beyond science, I've also turned to cinema to articulate how enmeshed I feel with my nine-month-old.
- At my lowest, I joke about how being a breastfeeding mother is like giving my kid my life force and beauty, akin to the gory thriller "The Substance."
- But often I think about my connection with my son in terms of "E.T.": He's my big-eyed baby alien, and I'm the human Elliot who feels his pain and never wants him to leave.
Worthy of your time: There are biological reasons why postpartum moms don't just "bounce back" to the way they were pre-pregnancy.
