My husband and I have two sets of twins (our own). All four babies weighed less than four pounds each. They are in good health now, but does their small size put them at risk for more diseases in adult life?

Studies of twins from around the world don't support that conclusion. Despite lower birth weights, twins have the same amount of many adult diseases. This includes diabetes, thyroid problems, and heart disease. They have the same life expectancy and mortality rate as the general population. This means they live as long as everyone else and die at about the same age.

A recent study from Denmark used the Twin Registry (data collected on twins) to assess back and neck pain. They found twins have the same amount of back pain alone, neck pain alone, or back and neck pain together as the general population.

Twins are considered part of the general population and don't need to be studied separately when it comes to health issues.