Where Metformin Fits in GDM

Metformin comes up quickly in GDM conversations, usually because it is a tablet and insulin is an injection. That preference is understandable, and the picture is more mixed than it first appears.

Insulin is the recommended first-line medication for GDM. Metformin may be considered as an alternative for women who decline insulin or cannot afford it — a consideration that carries real weight in India, where insulin, pens and strips are usually paid for out of pocket.

The limitation to know is its failure rate. Around half of women started on metformin for GDM end up needing insulin as well, because the tablet alone does not bring readings to target.

That does not make metformin pointless. It makes it a reasonable option in specific circumstances, with the expectation that it may not be the final answer.

Unlike insulin, metformin does cross the placenta, which is why the choice is a clinical judgement rather than a matter of convenience, and why it is your doctor's decision to make with you.

The practical advice: if cost is the reason you are hoping for tablets, say that directly rather than declining insulin without explaining. Teams can often help with the cost, and they can only do that if they know it is the obstacle.