What are the consequences of poor glycaemic (blood-sugar) control in pregnancy?
The mother could become very seriously ill if her blood-sugar is allowed to drift wildly. Both very low and very high blood glucose can be dangerous, even life-threatening. As for the fetus, poor diabetic control is estimated to be responsible for close to half of all babies lost either in the form of stillbirth or infant death soon after delivery.
What sort of blood glucose levels should a mother aim for?
The affected mother will need to check her blood glucose anything between two to five times a day throughout the course of the pregnancy.
She should be aiming for a level of between 4 and 7. The glucose level should be nearer four before her breakfast and nearer seven two hours after her main meal. In reality, this may be difficult to achieve and a drift by a factor of one from this range is generally considered acceptable, provided it is not persistent.
If a mother has eye complications as result of diabetes, will pregnancy make these worse?
The most common diabetic eye complication is retinopathy. If she already has this, the symptoms may get worse. This is, however, strictly temporary and her eyes will go back to the pre-pregnancy status soon after the end of the pregnancy.
All diabetic expectant mothers should have their eyes examined during pregnancy, to keep track of existing retinopathy and to detect any retinopathy which may develop for the first time during pregnancy.
What if her kidneys have been affected by diabetes?
It depends on the extent of renal (kidney) disease. If the only detectable problem is loss of protein in the urine, then pregnancy should not have any significant effect. It would not make the renal disease worse and there will be only a slight increase in the possibility of fetal growth restriction. However, she is at a slightly increased risk of developing pre-eclampsia.
If, on the other hand, her renal disease has already caused hypertension before pregnancy, then the risk of developing pre-eclampsia is quite significantly increased. This, in turn, may lead to significant fetal growth restriction and/or prematurity. More than a third of such patients have premature delivery.
What should a diabetic mother expect if the baby is delivered prematurely?
In any situation, it depends on the degree of prematurity. As a rule, babies of diabetic mothers tend to fare less well at every stage of the pregnancy. Good diabetic control quite significantly reduces the difference, but it does not eliminate it altogether. The doctors will strive to minimise the possibility of a premature delivery as much as they can, but this is not always possible. In the presence of significant complications, the mother's own well-being is paramount and early delivery may become inevitable as a life-saving measure.
What are the main problems afflicting premature babies?
The biggest problem is usually lung function. Babies of diabetic mothers are particularly prone to poor lung function. Normally, when a premature delivery is anticipated, a short course of steroid injections over 24 to 48 hours is administered. The steroids stimulate the fetal lungs to produce a chemical (surfactant) which helps to facilitate good lung function.
For diabetic patients, however, this is not a straightforward affair. Firstly, steroids disrupt diabetic control as they increase insulin resistance, which will make the mother prone to high blood sugar. Secondly, the fetus of a diabetic mother does not respond quite as well to steroids. Most obstetricians agree, however, that if prematurity is a distinct possibility, steroids should be given and close and intensive blood sugar surveillance maintained.