Weight gain and metformin


I am currently 11 weeks and 4 days pregnant. I have been on metformin and have not yet gained any weight. Maybe a fraction of a pound but it fluctuates. My doctor told me to only gain 25 lbs durring pregnancy. I am a normal pre pregnancy BMI of 27. His recommendations are based on lots of factors including my pelvic size. I have been very happy thus far with not gaining durring my first trimester because I know I will pack on the pounds later in pregnancy.

I’m stoping my metformin at 12 weeks. I’m scared I’m going start packing on the pounds to quick after that. Does anyone have experience with stoping metformin durring pregnancy and weather their weight gain stayed appropriate or ballooned afterwards?


I don’t think you should worry about it. I didn’t gain any weight during the first trimester and I stopped Metformin at 15 weeks, so it’s a little hard to tell because by that point, I was gaining natural baby weight anyway so any weight I might’ve gained by stopping Metformin was in the noise. But I don’t think it caused any significant difference. My feeling on it (although you should ask your doctor) is that the Metformin helps us, at least indirectly, by regulating some hormone problems. When you’re pregnant, your body changes its hormone response anyway, so the typical factors that cause us to gain weight aren’t present in the same way they are when not pregnant. But I would talk it over with your doctor, especially if he has a weight guideline he wants you to stick to. He should be able to help you manage that, and if going off Metformin is going to cause some weight gain, he should help you prepare for that as well.


I stopped Metformin at about 12 weeks. The thing was that the second trimester was when the pounds started piling on anyway. I passed my gestational diabetes tests at both 16 and 28 weeks. After the delivery, the weight came off (probably because of breastfeeding) and I never went back on the stuff.

When I took it before I was pregnant, the Metformin didn’t make me lose or gain weight, but I didn’t take it for a long period of time beforehand–it was more of a precaution. The drug probably affects everyone differently.


I agree with the other ladies in that it is difficult to tell since lbs start to increase in the second trimester. I stopped mine about 12wks. Since then I have gained a couple lbs, but it hasn’t piled on or anything so…of course I do have gestational diabetes so have to keep my sugars under control, but on this diet I am actually eating much more than I was before and still haven’t packed it on. I have gained about 8lbs total so far and about 4 of that was in the first trimester so 4lbs in the past 10wks.

I know this may be a little TMI, but just as a heads up…May want to make sure you are drinking tons of fluids (like 6–16.9oz bottles of water per day) and eat bananas and such because I noticed that since stopping the Metformin I have trouble with constipation which I have never had issues with before and at times can be about 3lbs heavier just from not having gone so…Yikes! They gave me colace, but that took three days to really start working. Now I am back down and just trying to stay cleaned out so I don’t get constipated again. No Fun!


Thank you girls! My last metformin is tonight! I’m a little less nervous now that I know you girls gained appropriately after stoping. I realy want a chance at a vaginal delivery and I guess I have a narrower pelvis so if I put on too many pounds I’m counting myself out. Kinda stressfull. Kash- awesome way of explaining the hormone difference. Deffinalty put my mind at ease
Babies- glad you passed the gestational diebetic test. Good to know there is hope
Ahhny- not tmi at allbut a great warning. I already suffer from more then occasional constipation. I might have to get on some routine colace before it gets too bad.

Thanks again, I truly appreciate you helping me down frm my freak out. :smiley:


Since BabiesAreCute mentioned it, I thought I’d add that, for me, breastfeeding did nothing for weight loss–at one year later, I’m still only 10 pounds under my max pregnancy weight. I breastfed for 6 months and then quit (for many reasons, one of which was to go back on Metformin) and didn’t lose a pound with either one. Looks like I just got the short end of the stick. :.( But some people have success with one or both, and some people find that their body chemistry changes enough after a pregnancy that they don’t have the same hormone problems they used to! Congratulations on your second trimester. :.)