I had GDM in first pregnancy. I started second pregnancy with A1c 5.1% at 5 weeks and at 11 weeks I already have A1c 5.5%, does this mean that these 6 weeks my blood sugar was higher than average for a1c 5.5%? I mean A1c measures average for 3 months and here it's a big change in just 6 weeks, so probably my numbers were quite high this time to equalize A1c as 5.5%? Or I don't understand A1c test? For example firt 1.5 months it was OK, second 1.5 months it was high and on average it was 5.5%?
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Rapid change in A1c
- Thread starter kalabati
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Hi
HbA1c doesn't actually measure blood glucose. It counts the number of red blood cells that have at some point had a glucose molecule attached to them - this is a proxy for blood glucose levels. Because red blood cells live around three months, the test looks back that far, but there's a big skew towards recent weeks. So it's not an "average" of anything.
I'm assuming that your medical team will be monitoring your BG closely because of your previous experience.
That said, 5.5% or 36 mmol/mol is an absolutely normal reading, on the low side. There is a bit of allowable error in the HcA1c test (5% of the reading either way) so the actual value is somewhere in the range 34ish to 38ish.
I'm also attaching a graph that shows what normal - non-diabetic - blood glucose looks like. Unfortunately there have been moves recently to persuade people that what has always been accepted as normal BG is actually "high" - these people generally have something to sell and a vested interest in creating anxiety. Different countries have slightly different standards, but most use a range around 36-41 or 42 to define "normal".
HbA1c doesn't actually measure blood glucose. It counts the number of red blood cells that have at some point had a glucose molecule attached to them - this is a proxy for blood glucose levels. Because red blood cells live around three months, the test looks back that far, but there's a big skew towards recent weeks. So it's not an "average" of anything.
I'm assuming that your medical team will be monitoring your BG closely because of your previous experience.
That said, 5.5% or 36 mmol/mol is an absolutely normal reading, on the low side. There is a bit of allowable error in the HcA1c test (5% of the reading either way) so the actual value is somewhere in the range 34ish to 38ish.
I'm also attaching a graph that shows what normal - non-diabetic - blood glucose looks like. Unfortunately there have been moves recently to persuade people that what has always been accepted as normal BG is actually "high" - these people generally have something to sell and a vested interest in creating anxiety. Different countries have slightly different standards, but most use a range around 36-41 or 42 to define "normal".
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When I was pregnant (admittedly a very long time ago, my youngest is 28) my team did fructosamine tests rather than hba1cs because they reflect the last 2-3 weeks of blood sugars, rather than 3 months for the hba1c.
Though I know that hba1cs tend to be influenced more by the most recent blood sugars, as more of the older red blood cells will have died.
www.diabetes.co.uk
Congratulations on the pregnancy.
Though I know that hba1cs tend to be influenced more by the most recent blood sugars, as more of the older red blood cells will have died.
Glycosylated haemoglobin & diabetes. HbA1c facts, units, diagnosis, testing frequency, limitations, control & conversion. How blood glucose levels link to A1c.
Glycosylated haemoglobin & diabetes. HbA1c facts, units, diagnosis, test frequency, limitations, control, conversion. How blood glucose levels link to A1c.
www.diabetes.co.uk
Congratulations on the pregnancy.
