Influence And Intervention Studies Of Vitamin B12 For Small For Gestational Age Infants’ Brain Development

Objectives:To understand the impacts of vitamin B12(VB12)and homocysteine(Hcy)on fetal development by detecting the difference in levels of serum VB12, Hcy of two group neonatal between small for gestational age(SGA)infants and appropriate for gestational age(AGA) infants with different gestational age. Through the early intervention with VB12 for SGA infants, the chage of levels of serum VB12 and behavioral neurological assessment score were monitored after the intervention, to explore the effects of the early intervention of VB12 for brain injury in SGA infants.Methods:According to the relationship between gestational age and birth weight,the subjects enrolled in the study were divided into SGA group(group A: preterm SGA infants; group C: full-term SGA infants) and AGA group(group B: preterm AGA infants; group D:full-term AGA infants). Blood samples were collected after birth within 0-24 h, and the levels of serum vitamin B12 and homocysteine were measured by ELISA, then respectively analyzed the relationship between serum VB12, Hcy levels and birth weight,gestational age at birth and compared the serum levels of VB12 and Hcy between two groups children of SGA and AGA with different gestational age. Neonatal behavioral neurological assessment(NBNA) were used for the assessment of behavioral neurological scores in the group C full-term SGA infants and the group D full-term AGA infants at postnatal day 2~3, by which compared behavioral capacity between these two groups infants after birth. Furthermore the group A preterm SGA infants, group C full-term SGA infants were respectively divided randomly into the intervention group and the non-intervention group, the intervention group was given vitamin B12 in three weeks from the second week, and the non-intervention group was not supplemented, then detected the serum levels of vitamin B12 respectively, meanwhile performing behavioral neurologicalassessment for group C full-term SGA infants.Results:1、The relationship between the levels of serum VB12, Hcy and birth weight,gestational age at birth:the levels of serum vitamin B12 and birth weight,gestational age was positively correlated, the correlation coefficients were respectively 0.564, 0.367(all p<0.05); and the levels of serum homocysteine and birth weight, gestational age was negatively correlated, the correlation coefficients were respectively-0.569,-0.317(all p<0.05).2、The differences in levels of serum VB12 and Hcy in SGA and AGA infants with different gestational age at birth: Compared with the preterm AGA group, the preterm SGA group had lower levels of serum VB12 and higher levels of serum Hcy(p<0.01); The full-term SGA group had lower levels of serum VB12 and higher levels of serum Hcy in contrast to the full-term AGA group(p<0.01);3、The results of behavioral neurological assessment which was measured in full-term SGA and full-term AGA at postnatal day 2~3:by contrasting with the full-term AGA, the full-term SGA had significantly lower scores in NBNA total, capacity, passive muscle tension, active muscle tension and primitive reflexes(all p<0.05),and scoring projects in capacity and active muscle tension had a obviously gap, but general assessment scores between the two groups had no significant difference(p>0.05).4、Analysis of the serum VB12 change between the intervention group and the non-intervention group at birth and the fourth postnatal week of SGA group: at birth, the levels of serum VB12 of intervention group, non-intervention group in the preterm SGA group and full-term SGA group had no significant difference(all p>0.05); at the fourth postnatal week, compared with the non-intervention group, the levels of serum VB12 of intervention group increased significantly, the difference was statistically significant(all p<0.05).5、Behavior neurological assessment outcomes in the full-term SGA group postnatal day 2~3 and the fourth postnatal week: at postnatal day 2~3, two groups of children in full-term SGA scores in NBNA total score, capacity, passive muscle tension, active muscle tension, primitive reflexes and general assessment had no significant difference(all p>0.05); At the fourth postnatal week the two groups of children scores in NBNA total score,capacity, passive muscle tension, active muscle tension, primitive reflexes and generalassessment all enhanced than those at postnatal day 2~3, in which, the intervention group increased obviously in capacity, passive muscle tension and NBNA total score than non-intervention group,with a statistically significant difference(all p<0.05);while in passive muscle tension, primitive reflexes and general assessment, there was no statistically significant difference in scores of two groups(all p>0.05).Conclusions:1、The levels of serum vitamin B12 and birth weight, gestational age were positively correlated at birth;while the levels of serum homocysteine and birth weight, gestational age were negatively correlated,which prompt VB12 may affect fetal growth and development.2、The levels of serum vitamin B12 in SGA infants was lower than that in AGA infants at birth, opposite to vitamin B12,the levels of serum homocysteine was higher than that in AGA infants.3、Early NBNA score in full-term SGA infants was significantly lower than that in full-term AGA infants, mainly in the capacity and active muscle tension.4、Postnatal vitamin B12 supplementation could increase the levels of serum vitamin B12, and improve NBNA score, which maybe indicate that the brain injury of IUGR caused by vitamin B12 deficiency can be ameliorated through the supplement of vitamin B12 postnatal.