Prospective cohort study of physique growth of infants born with different weights aged 0-6 months

Abstract:

Objective：To investigate the physique growth of infants born with different weights within 6 months after birth. Methods：Totally 341 infants were recruited in this cohort study from the department of child health care in two hospitals in Chongqing from April 2010 to January 2012，including 145 macrosomia（M） and 196 normal birth weight（NBW） infants. Follow-up visit was carried out monthly with questionnaire and physique examination until the infants reaching the 6th month. Results：Overweight incidences of M infants aged 0-6 months were 5.8%，7.0%，4.7%，8.1%，12.8%，7.0% while those of NBW infants were respectively 1.4%，1.4%，5.0%，5.0%，4.2%，8.4%. Overweight occurred in both groups and significant differences were observed between M group and NBW group at the 5th month（?字2=5.695，P=0.034）. In M group，weight growth velocity of baby boy was faster than that of baby girl at 1-month-old（t=2.327，P=0.022），however，the result was inversed at 4-5 month-old（t=-2.216，P=0.029）. Weight growth velocity of M infants was slower at the first 3 months compared with that of NBW infants（t=-6.883，P=0.000）. There was no difference in growth of body length between two groups. The correlation anal－ysis demonstrated that weight-for-length Z score at 6-month-old was positively correlated with birth weight（P<0.05）. Conclusions：Development is faster in M infants than in NBW infants at 0-6 month，however，weight growth velocity is slower in M infants than in NBW infants at the first 3 months. Overweight incidence of 5-month-old M infants is the highest. Correlation is observed between birth weight and weight-for-length Z score at 6-month-old.