I have had type�1 diabetes for the past 20 years (I am 23 years old) and became pregnant nine months ago. I was in poor control. My hemoglobin A1c was 8.0% or somewhere around there, and my average blood sugars were around 150-250 mg/dl [8.3-13.9 mmol/L] constantly. I didn’t find out until I was about two weeks pregnant, and then I really didn’t get my blood sugars brought down until about nine or ten weeks along. Even so, they haven’t been all that great (very rarely over 200 mg/dl [11.1 mmol/L], less than once every two weeks or so, but not in the ideal rate). Usually, I run about 80-150 mg/dl [4.4-8.3 mmol/L], but, with all the information saying that my sugars needed to be down prior to conception and the first nine weeks, I was wondering what kind of birth defects I might have caused. I have had six or seven ultrasounds done, and they said that all the parts are formed correctly, but what other defects could happen? No one has mentioned anything to me, and I’m seriously worried about these things.

Babies of mothers with diabetes are at risk of defects in all organ systems. The spine and heart are the most commonly affected. The most sensitive time for the fetus is during the first eight weeks, when all the organs are forming. Once an abnormality occurs, it does not go away. However, if the baby gets through this early development without defects, then, with a few unusual exceptions, none should develop. Ultrasound is very good at ruling out neural tube defects (99%) and reasonably good at ruling out heart defects (50-75%, depending on where it is done). However, until the baby is born, no one can be 100% sure of the outcome.

It is important that you maintain good glucose control throughout the pregnancy for other reasons. Mothers with high blood sugars often have very large babies. These babies also have problems temporarily with their own sugar control after delivery because they make too much insulin. They are prone to hypoglycemia. Pediatricians are aware of this and will treat the baby until the baby adjusts its insulin production back to normal.

OWJ