November 8, 2000
Question from Rhode Island, USA:
I’m now in the (approximately) 20th week of pregnancy. My A1c is down to 4.6% or so. My meter readings average 114 mg/dl [6.3 mmol/L]. So far, I’ve been diet controlled and no insulin. I’m prone to lows to begin with and fear that insulin is going to make that problem worse.
If I have a one-hour reading of 176 mg/dl [9.8 mmol/L], and a two-hour reading of 86 mg/dl [4.8 mmol/L], is this cause for concern? Should I only be testing at two hours to make sure that my two-hour number is less than 120 mg/dl [6.7 mmol/L]? Does it matter if my one-hour number spikes, if my two-hour number is then low or within parameters? Will a high one-hour number be a problem for the baby?
In my practice I follow patients with gestational diabetes on diet control with a fasting and a one-hour post meal blood glucose test. If the fasting is greater than 100 mg/dl [5.6 mmol/L] and or the post-meal is greater than 130 mg/dl[7.2 mmol/L], then I will start insulin. Sometimes not very much is required. For example, if the post-meal is elevated but the fasting is normal, then some patients do well with a single injection of NPH (a long-acting type of insulin) in the morning. However, patients are different and insulin requirements will change during the course of the pregnancy.
In your case, it seems that, right after a meal, you have a significant elevation in blood glucose. This needs to be treated. Even just a mild elevation in blood sugar can result in excess fetal growth.