Effects of sialic acid in serum and breast milk on the growth and development of infants at different stages during pregnancy and lactation

Objective: To investigate the effects of sialic acid (SA) in serum and breast milk on the growth and development of infants at different stages of pregnancy and lactation. Methods: From January 2015 to January 2016, a total of 146 local women who underwent the prenatal check-up and delivery in our hospital and their children were enrolled. Their serum SA levels at 10th, 16th and 38th weeks during the pregnancy, and the levels of SA in breast milk at Day 3, 42 and 90 post-partum were examined by ELISA kit. And the mental development index (MDI) and psychomotor development index (PDI) of infants were evaluated at day 90 after birth with a 0~3-year-infant intelligence development scale. Results: The data from 133 pairs subjects were record completely. The serum SA level played a significant role in the early mental and psychomotor development of infants in the second trimester (P<0.01). The MDI were higher in pregnant women with high serum SA level during the third trimester than those with low level (P<0.05), which was also higher in pregnant women with high SA level in breast milk than those with low level in breast milk at day 3 and 42 post-partum (P<0.01). While the SA levels in serum or breast milk at early pregnancy and Day 90 after delivery had no effect on the mental and psychomotor development of infants (P>0.05). Moreover, logistic regression analysis showed that the serum SA levels were closely associated with MDI at second and last trimester, and were closely associated with PDI at second trimester (P<0.05). As for breast milk, its SA level was closely associated with MDI at Day 3 and 42 after delivery (P<0.05). Conclusion: The levels of maternal serum SA during the second trimester can promote the early mental and psychomotor development of the infant, and the high levels of SA in both serum and breast milk during late pregnancy and 1 month post-partum have a positive effect on the early mental development of the infants.