Why the fuss about the A1c in early pregnancy?

When someone with Type 1 or Type 2 diabetes becomes pregnant the main things to think about are: the mom’s own situation with regards to diabetes complications, her blood sugars and the baby.  The big issues for the baby are that he or she might have a congenital malformation, be too large at birth or have low blood sugars just after birth.  Of these the congenital malformation is by far the most important.  A large baby can be delivered by Caesarian section, a low sugar in the baby is readily treated but if the heart, kidney or spine are not formed correctly we can’t turn back the clock.

Several studies have looked at just how low the A1c (the usual measure of the average blood sugar) needs to be to be safe.  While some have said it should be under 6.0 (42 in the new units) most feel if it is under 7.0 (53 in the new units) at the time of conception then all should be fine.  Thus many diabetes associations strongly recommend deferring pregnancy if the A1c is over 7.0 (53 in the new units). If it is over this it does not mean there will be a problem, just more likely to have one.  For instance if the A1c is quite high at 10.0 (86 in the new units) then the risk of a congenital malformation is about 10%,  but still giving a 90% chance all will be okay.  Likewise the risk in the general population for a major congenital malformation is 1.5% and controlling the blood sugar, even when the A1c is perfect,  does not eliminate all risks. However, who would  take any risk  with their baby if it can be handled by controlling the blood sugar?

It is important that the sugars are controlled pre-conception, don’t wait until you find you are pregnant as controlling the sugars will take some time and all these organs in the baby are being formed in the first 6-7 weeks of pregnancy. If you do have a surprise pregnancy, then just get on top of the sugars as quickly as possible.

Getting the A1c down this low can be extraordinarily difficult for some people.  In some women there are just so many problems with her having hypoglycemia it becomes unsafe to try and push the A1c lower.  While the newer analogue insulins, pumps and sensors can help they do not work out for everyone.  Sometimes in our clinic after trying for a long time the problems with hypo’s in the mom force us into a discussion (involving mom, dad and diabetes team) to decide “do we go ahead with a less than perfect blood sugar”.

A final point is that some women can have great sugars but a high A1c.  Assuming the  sugars are tested many times a day and are fine, the explanation might be that in some people the hemoglobin in the blood that the A1c is  based on lasts longer in their blood or accepts glucose more readily than usual thus giving a falsely high A1c, more  on this later.