Correlation Between Pregnant Women’s Serum Hcy Level And Offspring’s Cognitive Ability:a Prospective Cohort Study

ObjectivesTo monitor the peripheral blood Hcy level of pregnant women during pregnancy,establish a mother-infant cohort,follow up the physical growth and cognitive ability of infants at 6 months and 12 months of age,and explore the relationship between maternal serum Hcy levels during pregnancy and the physical growth and cognitive development of infants.MethodsSelect 4-6 maternal health care service units in the urban area of Hefei.Pregnant women who receive mid-trimester health care services and are ready to give birth in the Hefei Maternal and Child Health Hospital are selected as the target population.Eligible research objects are randomly selected at a determined time.The basic information of the research object is collected by homemade questionnaire,including the age,cultural level and occupation of pregnant women and their spouses.At the same time,the serum homocysteine level of pregnant women was measured,the pregnancy outcome and the health status of the newborn were followed up,and the physical development and cognitive ability of the infants at 6 months and 12 months were monitored.Multivariate linear regression was used to analyze the relationship between maternal serum Hcy levels and offspring cognitive ability.ResultsThe average concentration of serum homocysteine in pregnant women in the second trimester was 4.44±1.19μmol/L.Take pregnant women’s serum homocysteine P₂₅and P₇₅as the boundary,pregnant women were divided into high Hcy group（>5.02μmol/L）,moderate Hcy group group（3.71μmol/L～5.02μmol/L）and low Hcy group（<3.71μmol/L）.There were 148 people in the low Hcy group,accounting for 24.9%,299people in the moderate Hcy group,accounting for 50.3%,and 147 people in the high Hcy group,accounting for 24.7%.The three groups of pregnant women took folic acid before pregnancy,and the differences in hemoglobin in the second trimester were statistically significant.The comparison of neonatal characteristics among the three groups found that there were differences in preterm birth and low birth weight,and the differences were statistically significant.After controlling for related confounding factors,compared with the high Hcy group,the moderate Hcy group（OR=0.161,95%CI:0.029-0.896）was a protective factor for the occurrence of low birth weight;compared with the high Hcy group,the low Hcy group（OR=0.094,95%CI:0.009～0.936）was also a protective factor for low birth weight.The physical development level of most infants is at the middle or upper-middle level,and the proportion of development below the middle level does not exceed 6.6%;the proportion of infant head circumference development at 6 months and 12 months of different development levels is basically not large.At 6 months of age,the proportions of length,weight,and head circumference were at the medium level,accounting for 58.4%,57.9%,74.9%and at 12 months of age,the proportions were all rose to 66.5%,68.7%,75.9%.Univariate analysis showed that the length of 6-month-old infants was related to gender,birth weight,premature birth,mother culture,and mode of delivery,infant weight is related to gender,birth weight,mode of delivery,and pre-pregnancy BMI,infant head circumference is related to gender,birth weight,preterm birth,mode of delivery,and pre-pregnancy BMI;the length of 12-month-old infants is related to gender,the weight of infants is related to gender,and the head circumference of infants is related to gender,birth weight,and mode of delivery.The results of correlation analysis showed that6-month-old length was positively correlated with birth length,birth weight,and maternal pre-pregnancy BMI;6-month-old weight was positively correlated with birth length,birth weight,and maternal pre-pregnancy BMI;6-month-old head circumference was positively correlated with birth length,birth weight,and maternal body mass index before pregnancy;12-month-old length was positively correlated with birth length and birth weight;12-month-old weight was positively correlated with birth length and birth weight;12-month-old head circumference was positively correlated with birth length and birth weight.The results of multivariate linear regression analysis showed that the partial regression coefficientsβof infant birth weight and 6-month-old length,weight,and head circumference were 0.002,0.001,0.001,the partial regression coefficientβof pre-pregnancy BMI and weight at 6 months was 0.027,the partial regression coefficientsβof infant birth weight and 12-month-old length,weight,and head circumference were 0.002,0.001,0.001.The normal development rates of 6-month-old infants’communication skills,coarse sports skills,fine sports skills,solve problems and personal social skills were 96.1%,93.0%,94.9%,97.8%,91.0%,The normal development rates of 12-month-old infants’communication skills,coarse sports skills,fine sports skills,solve problems and personal social skills were 92.2%,94.5%,95.0%,96.7%,92.5%.Univariate analysis showed that the communication ability development score of 6-month-old infants was related to parity,pre-pregnancy BMI,the developmental score of infant gross motor ability is related to parity and parity,personal-social development scores of infants are related to parity,parity,and second-trimester hemoglobin;the communication ability development score of12-month-old infants is related to gender and hemoglobin in the second trimester,gross motor development scores of infants are related to mode of delivery,the developmental score of infant’s fine motor ability is related to parity,mother’s culture and serum Hcy level,infant personal-social competence development scores related to gender,maternal culture,second-trimester hemoglobin.The results of correlation analysis showed that the 6-month-old personal-social ability development score was positively correlated with the birth weight of infants（r=0.102,P<0.05）,the 12-month-old communication ability development score was positively correlated with the hemoglobin level in the second trimester（r=0.111,P<0.05）,the fine motor development score was negatively correlated with the serum Hcy level of pregnant women in the second trimester（r=-0.123,P<0.05）.The results of multivariate linear regression analysis showed that the partial regression coefficientβof infant birth weight and 6-month-old personal-social ability development score was 0.003,the partial regression coefficientβof the second trimester hemoglobin level and infant birth weight and the 12-month-old communication ability development score were 0.105,0.001,the partial regression coefficientβof the serum Hcy level of pregnant women in the second trimester and the12-month-old fine motor ability development score was-0.959.ConclusionsPregnant women have better serum Hcy levels in the second trimester,all within the normal range.Whether taking folic acid before pregnancy affects the Hcy level in the second trimester.There is a correlation between the Hcy level in the second trimester and the occurrence of preterm birth and low birth weight.Lower Hcy level is a protective factor for low birth weight.The fine motor ability development scores of12-month-old infants were correlated with serum Hcy levels,and there was a negative correlation.In conclusion,pregnant women should supplement nutrients such as folic acid in time before pregnancy,and the serum Hcy level is monitored in the middle of the pregnancy to reduce the occurrence of bad pregnancy,promote better physical development and cognitive development of future generations.