Women who are 35 and older have the same chances as a younger woman of giving birth to a healthy baby—even though, on the face of it, that doesn't seem to be the case.
It's generally understood by doctors—and researchers, come to that—that older women run a higher risk of having a child born preterm, or before 37 weeks, or with a low birth weight of less than 2.5 kilograms.
Either outcome comes with health risks: a preterm baby is more likely to have a heart defect, a lung disorder, brain damage or delayed development, while those with a low birth weight have more respiratory, cognitive and neurological problems.
But when researchers from the London School of Economics dug a little deeper, they discovered that the mother's age, on its own, wasn't the cause. Instead, family income, the health of the woman and her general circumstances had much more of an impact on the wellbeing of the baby.
This became clear when they looked at the health of children born to the same mother, including any that were born when the woman was aged 35 or older.
It's good news for women who are delaying the start of a family. "Age is not the real cause of the increase in birth risks," said Alice Goisis, one of the researchers.