Why newborn babies don't cry tears - no matter how much they scream

Newborn baby. (Shutterstock)

New parents know the score: you've changed your baby, fed them, burped them and they still won't go to sleep, instead screaming at the top of their lungs. Their face is contorted, eyes screwed up, skin turning a deeper shade of red by the second and they're really testing out those lungs. You've made sure they can't possibly be hungry, thirsty, winded or sitting in a wet nappy.

So what on earth is wrong with them? Are they just pretending to cry? You can't see any tears falling from their cheeks. Well, no. They're not just putting on an Oscar-winning performance. Newborns typically won't shed any tears because their tear ducts are still developing after birth. In fact, it's normal for them not to shed any tears during the first few months of their live, according to pediatrician Tanya Remer Altmann.