It can cause the baby to be much larger than normal size.

You must ensure your diabetes is controlled during your pregnancy to ensure safe development of baby. Be sure to speak with your obgyn asap to ask this question and to formulate a plan of care.

The short answer is that it can if you do not regulate your numbers, you need to be followed closely by your OB provider and make sure to eat a healthy diet and check your sugar levels often. Take medication as prescribed, and be sure to inform your provider of your numbers.