Does insulin cross the placenta?

Patient: I’m pregnant with type two diabetes and was wondering does insulin cross the placenta? If so what harm does it do to the unborn child? I’m injecting a pretty good amount of insulin to control my blood sugar.

Doctor: Insulin crosses the placenta in very small amounts, insufficient to cause any harm to the unborn baby. On the other hand , increased sugar levels may affect your baby with macrosomia (large baby), birth defects, hypoglycemia after birth, increased chances of C-section due to large baby etc. Thus you need not be concerned about the increased amounts of insulin, but need to keep your sugar levels in control to avoid any harmful effects on your baby.