A ventricular septal defect (VSD), or hole in the heart, forms in early pregnancy. There’s nothing you did to cause it, and it’s very treatable.

A ventricular septal defect is a small hole in the wall that separates the two lower chambers of your heart. 

Blood winds up leaking between the two sides of the heart. This means the heart can’t pump blood as well as it needs to. It makes the heart and lungs work harder than they should.

We don’t know exactly why a VSD forms, but it happens in early pregnancy as your baby’s heart is developing.