Is it necessary baby gain weight every week?

A. Hai good evening !! Yes babies gain weight gradually per week on an average 100-200 gm per week ,400-900 gm per month. Monthly weight check up must be done to know the weight gain. By 5-6 months they double their birth weight. Exclusive breast milk or formula milk is suggested until 6 months,from 6 months onwards start semi solid foods.