| ObjectivesTo elucidate the changes in the levels of maternal vitamin D in three trimesters and to examine the effect of gestational vitamin D on developmental behaviors of toddlers at 18 months.MethodsProspective cohort study design was implemented and pregnant women were recruited in prenatal clinics of Ma’anshan Maternal and Child Healthcare Hospital.From May 2013 to September 2014,information on maternal health status,maternal demographic characteristics,vitamin D supplementation during pregnancy and neonatal characteristics was collected.Maternal blood samples in three trimesters were obtained and serum 25(OH)D was determined by radioimmunoassay.The Ages and Stages Questionnaires of third edition(ASQ-3)was performed to evaluate the developmental behaviors of toddlers in 18 months old.A total of 3 474 pregnant women were enrolled in our study.Excluded 162 pregnant women with pregnancy termination and 39 pregnant women gave birth to twins,there were 3 273 singleton live births.Excluded 250 toddlers without ASQ-3 outcomes in 18 months old,3 023mother-child pairs were included in this analysis.Because of the loss of 182 blood samples in first trimester,151 blood samples in second trimester and 290 blood samples in third trimester,current analysis contained 2 841 subjects,2 872 subjects and2 733 subjects respectively in each trimester.One-way analysis of variance andχ~2 test were used to compare the difference of vitamin D concentrations and rates of deficiency in different trimesters.χ~2 test was used to analyse the risk factors of evaluations on five ASQ-3 domains.Multivariable logistic regressions were conducted to examine the effect of maternal vitamin D in three trimesters on developmental behaviors of toddlers at 18 months.ResultsConcentrations and deficiency status of maternal serum vitamin D were different in three trimesters.The highest concentration of vitamin D was in second trimester(22.75±10.48 ng/ml)and the lowest concentration of vitamin D was in first trimester(18.18±8.40 ng/ml).The rate of vitamin D deficiency in three trimesters was 66.2%,46.5%and 58.8%.The prevalence of severe developmental delay of 3 023 toddlers was3.4%in gross motor domain,3.8%in fine motor domain,2.2%in communication domain,3.6%in problem-solving domain,and 3.7%in personal-social domain.The prevalence of mild developmental delay was 14.9%in gross motor domain,9.5%in fine motor domain,18.6%in communication domain,12.8%in problem-solving domain,and 9.7%in personal-social domain.The rate of developmental delay in gross motor domain with maternal vitamin D deficiency in three trimesters was 3.6%,3.1%,and 3.4%.The rate of developmental delay in fine motor domain with maternal vitamin D deficiency in three trimesters was 3.5%,4.6%,and 4.1%.The rate of developmental delay in communication domain with maternal vitamin D deficiency in three trimesters was 1.8%,2.1%,and 2.4%.The rate of developmental delay in problem-solving domain with maternal vitamin D deficiency in three trimesters was 3.5%,4.0%,and4.2%.The rate of developmental delay in personal-social domain with maternal vitamin D deficiency in three trimesters was 3.1%,4.1%,and 3.9%.Gross motor ability was associated with residence location,pre-pregnancy BMI and maternal IQ.Fine motor ability was associated with pre-pregnancy BMI,residence location,maternal IQ,family income,maternal education,pregnancy complications,birth weight,premature,and breastfeeding.Communication ability at 18 months was associated with residence location,child’s sex and breastfeeding.Problem-solving ability was associated with maternal education,birth weight and breastfeeding.Personal-social ability was associated with maternal education,child’s sex,premature and breastfeeding.After controlling for maternal age,residence location,monthly household income,pre-pregnancy BMI,educational level,gravidity,maternal IQ,pregnant complications,vitamin D supplementation during pregnancy,child’s sex,gestational age,birth weight,breastfeeding,and season,vitamin D deficiency in second trimester increased the risk of severe developmental delay in fine motor domain(OR=2.53,95%CI:1.30~4.91).Vitamin D deficiency in third trimester increased the risk of severe developmental delay in problem-solving domain(OR=3.74,95%CI:1.47~9.53).High concentration of vitamin D in third trimester could protect toddlers from severe developmental delay in fine motor domain(OR=0.98,95%CI:0.95~0.99)and in problem-solving domain(OR=0.96,95%CI:0.94~0.99).ConclusionThe level of vitamin D was the highest in second trimester of pregnancy,the second-highest in third trimester and the lowest in first trimester.Vitamin D levels in second trimester and in third trimester affected fine motor development of children in18 month old,and vitamin D deficiency in second trimester was harmful to fine motor development.Vitamin D level in third trimester affected problem-solving development of children in 18 month old,and vitamin D deficiency impaired their problem-solving ability. |
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