We went for our monthly ultrasound this morning and found out the weights of our twins are more than 20% different from each other, which they consider a critical difference. So now we have to go weekly for monitoring for the next 3 weeks. Twin A(boy) is 4lbs 3oz and Twin B(girl) is 3lbs 4oz. Our girl(B) is more active than our boy(A). they said the boy(A) is in the 65 percentile for weight but didn't tell what percentile for the girl is.