Babies sometimes trigger preterm labor to escape infections

Premature birth is the most common cause of infant mortality, and the biggest cause of preterm labor is an infection in the mother. For a long time, doctors assumed this was all about the mother—infections triggered labor directly, making her body overreact and causing contractions. But a new study shows that, at least in some cases, it’s the baby’s own immune system that causes preterm labor, and it could even be a way to escape the infection. This discovery overturns the conventional wisdom and points to entirely new ways to prevent premature birth.

Mother vs. Baby: In general, your body doesn’t like things that aren’t you. The immune system’s main task is to find cells with foreign DNA, like viruses and bacteria, and attack them. But there are downsides to that rule—for instance, if you’re growing a completely new person inside of you. Pregnancy has several ways to suppress the mother’s immune response to prevent it from attacking the baby. But the conventional wisdom has always said that the fetal immune system is simply too immature to do much during pregnancy.

“Waking Up” Early: Researchers at UC San Francisco have discovered that babies’ immune systems are actually just dormant, waiting for the right signal to turn them on after birth. It turns out, unfortunately, that infections in the mother can fool it into waking up early. And once the system is on, it starts attacking the mother’s cells, causing inflammation in the uterus and triggering contractions.

Hitting the Eject Button: This could simply be a mistake: babies’ immune systems have to be primed and ready to go, and sometimes this leads to a dangerous and untimely exit. But one of the study’s authors thinks premature birth could be an evolved eject button. “It could be a defense mechanism to exit a hostile uterine environment,” he said, “if you encounter trouble in the form of an infection or inflammation.” Normally, the womb is the place to be for developing babies, but sometimes it might have been worth the gamble to enter the world early.

The Upshot: Right now, the treatments for premature labor are aimed at the mother, treating her infection and trying to stop contractions. But this might be too little and too late when the real issue is the baby rejecting the mother—not the other way around. The infection could have come and gone already, possibly without the mother even noticing, but if it leaves the baby’s immune system activated, that’s the issue that has to be diagnosed early and treated. Recognizing this could open up a new range of possibilities for detecting and reducing the risk of premature birth.

Related
Startup can now screen IVF embryos for 1000+ diseases
Startup Orchid now offers whole genome sequencing for embryos used during IVF β€” but not everyone is convinced it’s worth the cost.
Mouse embryos grown in space for the first time
A mouse experiment on the International Space Station suggests humans might one day be able to reproduce in space.
Model human embryo, created from stem cells, survives past two weeks
A model human embryo capable of developing past day 14 could revolutionize our understanding of human development.
Scientists are growing animals in artificial wombs. Humans might be next.
Artificial wombs promise to give people a way to have biological children without putting their own health at risk.
First healthy mice with two dads β€” and no moms β€” born in Japan
For the first time, scientists have created healthy, fertile mouse pups using only the DNA of two adult males.
Up Next
No related content in the preview
Subscribe to Freethink for more great stories