As foetus spends more time deprived of oxygen and nutrients, instead of growing in womb, its cells actually begin to die.
Scientists have now discovered that high levels of a protein in the placenta have been linked to dangerously low birth weights for the first time, and it may offer a key to protecting babies from dying in the womb.
According to doctors, babies born at low birth weights do not get enough oxygen and nutrients in the womb.
Researchers say that birth weights under 5.5 lbs raise the risks that a baby will suffer from obesity, high blood pressure diabetes and heart disease in adulthood.
Researchers from the University of California, Los Angeles, found that production of a protein called humanin may ramp up to protect babies when the placenta is failing, suggesting the protein could some day be given as a life-saving supplement.
Babies weigh 5.5lbs or less at birth due to a condition called intrauterine growth restriction. This leads to growth impairment due to placental insufficiency.
This means that the protective sack that a baby develops in and receives its mother’s blood and oxygen through does not function properly and the foetus is partially deprived of these essentials.
If an ultrasound reveals that a foetus is smaller than expected during pregnancy, an obstetrician might tell the mother to eat more or to spend some time on bed rest, which can help to improve the fetus’s blood circulation.
Staying in the womb too long without getting enough oxygen and nutrients can even kill the foetus and in emergency cases doctors may induce an early delivery.
But, apart from these measures to manage intrauterine growth restriction, there is no reliable way to prevent or treat the condition, in part because its cause remains unclear.
However, according to UCLA researchers, a protein called humanin hold a key to protecting a foetus when the placenta fails to do so.
It helps break down carbohydrates and deliver nutrients to organs and muscles.
It also works as a defense mechanism against oxidative stress, a part of the metabolic process that releases free radicals into the body, where they roam and wreak havoc on other cells.
Research has found that oxidative stress effectively ages the placenta and it becomes weaker and its functions start to break down. This process slows the exchange of nutrients and oxygen between mother and baby.
Shockingly, as the foetus spends more and more time deprived of oxygen and nutrients, instead of growing in the womb, its cells actually begin to die off.
But the new study suggests that humanin's protective effect may help to prevent that.