But not in a rude way, okay.
The team asked 137 healthy women with low-risk, normal pregnancies to report on their stress between the 24th and 32nd week of pregnancy.
The study in Child Development found the children of those who reported more stress were more advanced at age two.
Earlier studies suggest stressed out mothers can pass it on to their babies.
They also suggest high stress levels can lead to restricted growth and birth defects in the unborn child.