I've heard conflicting advice from doctors. Some say to stop immediately, some say to stay on it and wean off once you get to 12 weeks, others say it's perfectly fine to be on through the whole pregnancy. It's in a drug category where there's not enough evidence to suggest either way that it is a problem or not, but there are increasing numbers of doctors using it with women who have PCOS and are pregnant.

I'm sure you know that metformin works by reducing insulin resistance, it also helps those of us with PCOS produce more glycodelin - a substance produced in the uterus that helps stop the body from attacking the baby and causing miscarriages. Women with PCOS don't produce enough, so being on metformin can help prevent miscarriages in the early stages of pregnancy.

I'd say it's very unlikely that being on metformin contributed to your sister's loss, sometimes you can do everything you can to prevent it, but it still happens anyway. For me, my first miscarriage happened as a direct result of recuding my dosage of metformin, but I also have another immune problem which doesn't help matters. For me, when I get pregnant again, I'll be on metformin until at least twelve weeks.

I hope this information helps somewhat. Of course, it's always best to discuss your medications during pregnancy with your doctor.

BW