Real Word Research On The Growth Pattern Of Preterm Infants With Different Birth Weight

Objective: To research the physical indexes and growth status of 0～4years old preterm infants with different birth weight based on analysis the real-world data.Methods Preterm infants were divided into normal birth weight(NBW)group,low birth weight(LBW)group,and very low birth weight(VLBW)group according to birth weight.The height,weight and head circumference at 1～48 months of the three group were calculated based on the database of real-world research methods,with establishing numerical table and growth curve diagram.Results: The weight,length and head circumference of the NBW group reached the full-term average,when their actual age was 2 months,10 months,and 8 months(P>0.05).From 0～2 years,the physical index gap between the LBW group and full-term was decreased.The physical index of LBW group reached to the full-term average level,when the actual age is2 years old.The weight difference between the LBW group and the full-term group was about 0.9kg(t=-8.623,P<0.01),and the height difference was about 1.5cm(t=-6.715,P<0.01).From 0～4 years,VLBW infants had lower physical indexes than the full-term average.The weight difference between the VLBW group and the full-term group was about3kg(t=-7.683,P<0.01),and the height difference was about 4cm(t=-4.895,P<0.01).Compared with the LBW and NBW groups,the VLBW group catch-up growth began at the age of 2 months,but at the age of 6months,the weight of the VLBW group was about 5 times of the birth weight,that of the LBW group was about 3 times,and that of the NBW group was less than 3 times.After 12 months,the growth velocity of the VLBW group slowed down most significantly.At the age of 24 months,the rates of stunting(42.3%),underweight(38.5%)and wasting(9%)were highest in VLBW group,and the rates of overweight/obesity(23.2%)were highest in NBW group(P < 0.05).At the age of four,the rates of stunting(44.4%),underweight(38.9%),wasting(22.2%)were still the highest in VLBW group.There were no statistically significant differences in overweight/obesity rates within groups.Conclusions:(I)The birth weight of preterm infants have influence on their postnatal physical growth: the lower birth weight is,the longer time it takes for physical indexes to reach the level of full-term infants.The weight,height and head circumference of preterm infants with normal birth weight reach the average level of term infants in infancy.Low birth weight preterm infants are basically close to the average level of full-term children at the age of 2.The catch-up growth of very low birth weight preterm infants starts late,which is fast within a certain period of time but short in duration,and has high rates of growth disorders.(II)The deadline for correction of gestational age in preterm infants should be further studied.It is suggested that preterm infants with normal birth weight should be corrected to 1 year old.(III)Normal birth weight preterm infants with excessive weight gain during infancy and very low birth weight preterm infants are at high risk of malnutrition in childhood,which deserves sufficient attention.