Women with type 1 or type 2 diabetes who have high sugars during conception and for the first few weeks of pregnancy have an increased risk of birth defects. These may be very minor, or they may be major problems such as heart, brain, spinal cord, or kidney problems. Good blood sugar control also decreases risk of miscarriage, and of diabetic complications for the mother. For these reasons, we help you to maintain good daily blood sugar values for at least two to three months before conception, as well as a good HbA1c value. The HbA1c is an average value of your blood sugars over the last two or three months. Ideally, this value should be under 7.0 %.
If you are already pregnant, it is still important to have good control, because babies can have other problems from high sugars. These problems can happen with any of the types of diabetes, including gestational diabetes. Sugar passes very easily through the placenta to the baby, although insulin does not. The baby will make extra insulin to use up all the sugar, and then will store the extra sugar as fat. Babies can get very big this way (asymmetrical macrosomia). This can make labour more difficult, and increase the chance of shoulder dystocia (shoulders that are stuck), forceps, or a Caesarean birth.
When the baby is making extra insulin, the lungs do not mature as they should. If the baby is born early, it may have more difficulty with breathing than other babies of the same gestational age. This is because surfactant, which the lungs need in order to breathe properly, does not form well when the baby is getting too much sugar and has to make extra insulin.
If the baby is getting extra sugar from the mother, this stops at delivery when the cord is cut. However, the baby will still continue to make extra insulin for a while. The baby can quickly use up its sugar supply and have a low blood sugar. This is uncomfortable for the baby, and can also be dangerous.
Babies may also be jaundiced, and may need to have phototherapy (light) treatment.
Good blood sugar control in pregnancy helps to avoid these problems in types 1 and 2 diabetes. Studies are now showing an increased risk of obesity and other medical problems in childhood and onwards when the baby is exposed to high sugars during pregnancy.
Women with GDM do not have high blood sugars long enough to have diabetic complications in the mother, and with normal blood sugars the baby does not have problems either.