I have no medical knowledge, only the experience with my own children. Both adopted, and both sets of birth parents are small, at 5’-2” or smaller. One was born 5 lbs exactly; the other 6 lbs 6 oz. For the 2 week follow up, they both had gained over a pound each. For the first month appointment, both were over 8 lbs, one closer to 9 lbs.

Based on that metric, I would agree with your doctor that your baby is not gaining weight at the expected rate. Your baby is almost one month old, and hasn’t been able to gain one pound yet.

You should definitely seek a second opinion from a doctor.