A Cohort Study About The Effect Of Bioactive Substances In Human Colostrum On Infants' Intelligence And Physical Development

Objectives To compare the concentrations of growth factors of human colostrums between spontaneous labor and cesarean section, and analyze the effect of body weight during pregnancy and caesarean section on delayed onset of lactation. Explore the effect of growth factors in human colostrum on early intelligence and physical development of infants, and supply some scientific datas for infant who have a better devclopment in future.Methods A voluntary sample of pregnant women were selected in maternal and child health care hospital in Hefei, Anhui Province from January 1st, 2008 to September 30th, 2008. All participants could response clearly and didn't have any psychological disorders. Their socio-demographic data, physical and psychological health information were assessed by a questionnaire. Their deliveries were observed and recorded. Venous blood serum during 6-24h after parturition and hunman colostrum samples from 2nd to 5th day were reserved for longtime in ultra-low temperature refrigerator. The serum prolactin and growth hormone were measured using chemiluminescent immunoassay and radioimmunity assay, and the levels of IGF-1, EGF are tested using the technique of ABC-ELISA. Lactation guidance was provided and onset of lactation data was collected in the hospital and on days 0-3 after parturition, and onset of lactation was defined based on maternal perception of changes in breast fullness. The breastfeeding datas were obtained by the telephone at 2nd and 4th month after delivery. and the participants were appointmented to designated place for evaluation with Bayley Scales of Infant Development of China Revision (BSID-CR) when infants reach16-18 months old.Statistical analysis: the change of concentrations of growth factors of human colostrums from 2nd to 5th day after parturition were described, and the results were analyzed and compared by Mann-Whitney U test, and Pearsonχ2 was analyzed to compare perceived milk yield between the different mode of delivery. The rate of delayed onset of lactation were described, and Bivariate and multivariate logistic regression model analyses were performed after controlling for the effects of maternal age, registered permanent residence and educational level. the difference of MDI and PDI for the group of having different levers of growth factors were compared in an analysis-of-covariance model adjusting for the effects of maternal age, registered permanent residence, educational level and perceived economic condition. Meanwhile, to analyze the concentration of growth factors in human colostrums and the indexes of the body length, weight and head circumference after parturition using the pearson relation analysis.Results There was a significantly lower postpartum prolactin (PRL) level in the caesarean section group (221.94±90.82 ng/ml) compared with spontaneous labor group (361.67±80.74 ng/ml) (P<0.05). and the GH in the caessrean was higher than that spontaneous's (P<0.05). The levels of IGF-1 of the colostrum in the cesarean section group were higher significantly than those of the spontaneous group from 2nd to 3rd after delivery (P<0. 05), and the perceive milk yeld in the cesarean section group were lower significantly than spontaneous group from 2nd to 3rd after delivery (P<0. 05). From 4th to 5th day after parturition, there was no significant difference in IGF-1 and perceived milk yeild between the two groups (P>0.05). Meanwhile, there was no significant difference in EGF between the two groups from 2nd to5th day after parturition(P>0.05). A total of 642(52.2%) and 270 (22.0%) cases for breast feeding were found among participants at the 2nd and 4th month after parturition. There was singnificant for feeding types between vaginal delivery and caesarean section. The rate of delayed onset of lactation for caesarean section was 15.8%, higher than that for vaginal delivery which was only 8.1%. Meanwhile, delayed onset of lactation occurred in 12.4% of 1 627 women was associated with BMI during early pregnancy>21.5(crude RR: 1.94(95%CI 1.27-2.96); and BMI before parturition>28.5 (crude RR: 2.52(95%CI 1.62-3.93); adjusted RR: 2.14(95%CI 1.37-3.35) and caesarean section (crude RR: 1.50(95%CI 1.30-1.74); adjusted RR: 1.46(95%CI 1.28-1.66). There was no significence for MDI and PDI among the different levers of IGF-1 group by an analysis-of-covariance model. PDI of the infants who had low lever group were lower than group which had high lever EGF. MDI was no significant difference among the different EGF levers group. Concentrations of IGF-1 in the colostrums were positively correlated with the hight of infants at 3 month, 6 month, and 9 month after delivery. Meanwhile, concentrations of EGF in the colostrums were positively correlated with head circumference at 9 mongth after parturition.Conclusions Caesarean section is significantly associated with lower postpartum PRL and the higher IGF-1 in serum, which is related to the delayed onset of lactation and the lower milk yield. IGF-1 and EGF secreted from the breast may participate the modulation of infant's nutritional metabolism and growth possibly by facilitating infant's gastrointestinal development and by benefiting the absorption and utilization of nourishment. Early lactation success is strongly influenced by potentially modifiable factors such as maternal body weight during pregnancy and caesarean section.