9 month ki sonography me fetal weight 3 kg tha 7 din baad jab baby ka birth hua baby ka weight 2.5 kg hi tha.... 7 din me weight badne ki bajay ghat kaise gaya

A. in sonography the weight of the baby is not accurate and in sonography the weight of the baby along with the amniotic fluid is also there so obviously loss of weight is pretty ok need not be worried about like in my sonography my daughter's weight was supposed to be around 4.5 kg but she was born 3.6 kg