What is the average weight gain per month in the first 12 months?

Question

My nine month old twin girls are a little low on weight gain. My maternal nurse said that's ok because there were born early and twins are generally smaller that a singleton. Last month my girls only put on 200 grams each in a month. They are feeding well and have normal bowel movements and wet nappies. They are very active babies. not walking but crawling, rolling and kicking around. They have 2 sleeps a day and do sleep through the night. One twin does have a heart condition. What is the average weigh gain. Please only answer in grams or kilograms because I don't live in US and don't understand the pounds. Please convert if you can. Thank you. All answers will be appreciated, And please no nasty answers.

Answer 1

For the first 4-6 months or so, 'average' gain is about 2 pounds (about 900 grams) per month, though normal babies may gain less (about 500 grams) or more (2 Kg or more.)

After 6 months, average gain drops to around 12 ounces-one pound (roughly 600-900 grams) per month.

But it's also important to recognize that babies do NOT gain weight steadily every week, or even every month. They have growth spurts where they gain a lot, and then may go for a few weeks/months gaining very little.  So a single low weight check is almost never cause for concern, as long as everything else is fine.