Blood Sugars in Early Pregnancy

Hello all. My wife (T1) and I recently found out we are pregnant and are just beginning week 5. Similar to what many people have experienced, we found that right before getting the positive pregnancy test (at week 4) and the following week her blood sugars were running much higher than usual. We had to increase her Basal by a lot to avoid the high spikes (particularly in mid-morning).

However, today it looks like her blood sugar is running much lower than the previous few days, and she seems to keep going low, even after eating some candy. I know that most T1 pregnant women find that their insulin requirements decrease in the first trimester, but based on what I have found we shouldn’t expect this until around week 8 or so.

Has anyone else also experienced an increase in insulin requirements in early pregnancy (weeks 3-5) to then suddenly finding their needs decrease? We have been making a lot of adjustments to her Basal, so its possible we got too aggressive, although the neurotic side of me is of course worried there is an issue with the pregnancy.

While there are general trends in BG during semesters, the daily fluctuations are huge. The good thing is that it sounds like your wife monitors closely and is comfortable adjusting insulin on her own, which is super helpful. The best advice I can give is don’t let anything that looks like a pattern go for more than 2 days, but do wait the 2 days before making further major changes. (Of course during that time, treat lows and highs as appropriate.)

Bigger-picture advice, if I may: having a child means not having any control over a whole host of things (everything?) while you desperately try to. So one lesson to already work on during pregnancy for both of you is to let go of that particular illusion and as much as possible the neuroses. (I have the same tendency you describe, so I know how hard that is.)

Best of luck!


Wanted to check back in since its been a few months. So far everything has been going pretty well! Just had the fetal echocardiogram and the babies heart looks great, which has been my main concern since heart defects are among the more common complication among T1s.

Overall my wife’s insulin needs have followed the common profile of most T1s. During weeks 10-14 or so we experienced a lot of hypos, and had to ramp down her basal pretty significantly. And just this past week (21 for the baby) she’s started to experience some sticky hypers, so we’ve had to increase her Basal.

The cause for my initial post was due to us increasing her Basal much, much too aggressively. Since then, we’ve not changed her total daily Basal amounts by more than 1-2 units, and things have been generally more stable.


Wonderful update! Wishing you a continued sense of calm, to the degree possible, until you get to meet your baby Earth-side!

(My own daughter just turned 18 months and I still remember how helpful it was to have this community here to discuss things with during pregnancy.)


I had random inexplicable lows shortly after implantation both last time (which ended up being a chemical pregancy, sadly) and this time (which hopefully is viable, I’m only at 5 weeks). I read somewhere that a batch of lows prior to the placenta developing is somewhat typical. Not sure WHERE I read it though.

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