Among the complications that can occur during a pregnancy is gestational diabetes. Though gestational diabetes usually goes away after pregnancy, its risks may not always.

Babies unable to grow to the size they're genetically supposed to reach suffer from intrauterine growth restriction, a risk factor for future cardiovascular problems.

We've known for decades that smoking during pregnancy is potentially damaging for the baby, and has been linked to various birth defects, premature birth, underdeveloped lungs, low birthweight and many other problems.