The survey on growth retardation incidence of extremely and very low birth weight infants

Abstract

Objective To research the incidences of intrauterine growth retardation(IUGR) and extrauterine growth retardation (EUGR) of extremely and very low birth weight infants,which would be helpful to growth monitoring and therapeutic intervention after hospital discharge.Methods Clinical data of extremely and very low birth weight preterm infants,who discharged from July 1 st,2010 to June 30th,2011,were collected retrospectively from 9 neonatal intensive care units of 9 cities in Pearl River Delta,Guangdong province.The body weight at birth and on discharge of each infant was compared to the expected value based on the intrauterine growth data and postmenstrual day on discharge.Growth retardation was defined as measured body weight ≤ 10 th percentile of the expected value.In each specific group,the number of infants with ≤10 th percentile was counted and the percentages of patients who had values≤ 10 th percentile at birth and on discharge were calculated.And the increasing incidence from IUGR to EUGR in each specific group was also calculated.The growth curve used for assessing body weight of different gestational age infants was Fetal-infant Growth Chart for Preterm Infants (WHO Growth Standards version).Results Three hundred and eighteen cases of extremely and very low birth weight infants were enrolled in this research.The incidence of IUGR was 33.3％ (106/318),while the incidence of EUGR was 70.8％ (225/318).In each group divided by gestational age (＜ 30 week、＜ 32 week 、≥ 32 week),the incidence of EUGR were 55.7 ％ (68/122),66.9％ (79/113) and 94.0％ (79/83) (x2 =34.964,P =0.000),which increased by 49.2％ (60/122),51.3％ (58/113) and 1.2％ (1/83) from IUGR (x2 =63.024,P =0.000).In each group divided by birth weight(≤ 1200 g、≤ 1350 g、＞ 1350 g),the incidence of EUGR were 83.8％ (88/105),65.3％ (66/101)and 63.4％ (71/112) (x2 =13.009,P =0.001),which increased by 42.9 ％ (45/105),35.6 ％ (36/101) and 33.9％ (38/112) from IUGR (x2 =2.045,P =0.360).But there were no significant difference between single fetus and multiple fetuses (P ＞ 0.05).Conelusion EUGR was still a serious problem in extremely and very low birth weight infants.The incidence of EUGR increased while the gestational age was increasing or birth weight was decreasing.And the increasing incidence from IUGR to EUGR increased while gestational age was decreasing.But there was no significant association with the number of fetus. Key words: Infant,preterm; Infant,extremely low birth weight; Infant,very low birth weight; Intrauterine growth retardation; Extrauterine growth retardation