The average full-term newborn is about 50cm tall and has a birth weight of about 3.3kg. newborns are born with a growth curve, and there are different curves for different problems. preterm babies have a growth curve, and there are growth curves for boys and girls, and there are also growth curves for normal full-term babies. the WHO, or World Health Organization, growth curve, and there are also growth curves for Chinese boys and girls. The lowest is P3, followed by P15, P50 or P85-P97. P3 or below and P97 or above are not normal, while P3-P97 are normal. P30-P97 is also classified, P3 to P15-P25 range, called the lower middle, between P25-P75 is the middle, P75-P97 is the upper middle, P97 and above is called the upper, that is, too large, normal to maintain the best in P25-P75, which means P50, the median up and down belongs to the better weight or height. Premature babies will be relatively small, preterm babies have different gestational age, there are boys and girls, the growth curve is also the same, from P3, P10, P50, P90 to P97, there are weight, head circumference, height curve, mainly by the neonatologist to assess, according to different gestational age, the height and weight at birth for comparison, for example, 34 weeks of preterm babies, weight in the midline range is about 2.5kg Depending on the gestational age, sex, and day, different standards will be set. It is important to find the percentile on the growth curve and to assess whether the newborn can continue to grow along the percentile in the future, and to compare whether the three values are growing proportionally.