Investigation The Pregnant Women's Serum Vitamin D Level In Nanchong Area And Preliminary Study On The Relationship Between Serum Vitamin D And Several Pregnancy-related Diseases

Objective: To understand the deficiency and the influencing factors of vitamin D during gestation period.Serum vitamin D of normal pregnant women who regular pre-natal examination in affiliated hospital of north sichuan medical college was detected.To explore the relationship between vitamin D and pregnancy-related diseases and to provide a reference about the rational vitamin D supplementation for pregnant women in Nanchong area.Methods: From July 1,2017 to June 30,2018,total l974 cases of singleton pregnant women and 409 pregnant women with pregnancy-related diseases(include 242 cases of gestational diabetes mellitus GDM,144 cases of intrahepatic cholestasis of pregnancy,23 cases of hypertensive disorders of pregnancy)were eligible for inclusion criteria in the outpatient clinic and hospital delivery of the affiliated hospital of north sichuan medical College.The general data and pregnancy outcome of the patients were recorded and the vitamin D value during pregnancy was detected by high performance liquid chromatography-tandem mass spectrometry.The relationship between vitamin D level and pregnancy-related diseases were analyzed by single factor analysis and unconditional binomial logistic regression.Results:1.The mean value of serum vitamin D in normal pregnant women in the first,second,third trimester were19.28±7.74ng/mL,27.57±9.93ng/mL,25.07± 10.54ng/mL respectively.the first trimester was the lowest and the second trimester was the highest.2.The overall adequacy ratio of pregnant women's serum vitamin Din Nanchong was only 24.04%,and the proportion of vitamin D deficiency,insufficiency and adequacy of pregnant women in the firsttrimester were 57.95%,32.08% and 9.97% respectively.The proportion of vitamin D deficiency,insufficiency and adequacy of pregnantwomen in the second trimester were 24%,38.8% and 37.2% respectively.The proportion of vitamin D deficiency,insufficiency and adequacy of pregnant women in the third trimester were 35.69%,34.84% and 29.46% respectively.The rate of vitamin D deficiency in the first trimester was the highest and the second trimester was the lowest.3.During gestation period,Vitamin D level of pregnant women in summer and autumn were significantly higher than that in winter and spring,the rate of vitamin D deficiency were lower in summer and autumn than that in winter and spring(P< 0.05).4.Pregnant women's vitamin D level in the third trimester was related to age,vitamin D level of pregnant women in less 25 years old group is lower than that in 30-34 years old group and(greater than or equal to 35 years old,less than or equal to 40 years old)group,vitamin D level of pregnant women in the first trimester and second trimester were not correlated with age.5.There were no difference in vitamin D levels among pregnant women with different pregnancy times and delivery times(P<0.05).6.Univariate analysis showed that the pregnant women's vitamin D level in the ICP group were lower than that in the non-ICP group in the third and first trimester,the difference was statistically significant(P<0.05).there was no correlation between the occurrence of ICP and vitamin D level by multivariate analysis.7.Univariate analysis showed that the pregnant women's age was associated with GDM and hypertensive disorder of pregnancy(P<0.05).Multivariate regression analysis showed that pregnant women's age was positively correlated with and GDM and hypertensive disorder of pregnancy(P<0.001,OR=1.083;P<0.001,OR=1.233).8.Univariate analysis showed that Vitamin D level in GDM group was higher than that in non-GDM group(P=0.01<0.05).Multivariate analysis showed that vitamin D level in early pregnancy was positively correlated with the occurrence of gestational diabetes mellitus.The higher the level of vitamin D,the higher the risk of GDM(P=0.021 < 0.05,OR=1.036).9.Multivariate analysis showed that serum vitamin D during pregnancy was positively correlated with hypertensive disorder of pregnancy.The higher the vitamin D level,the lower the risk of hypertensive disorder of pregnancy(P<0.049,OR=0.950).Conclusion:1.Vitamin D deficiency was common in pregnant women in Nanchong area,especially in first trimester the vitamin D supplement should be strengthened.2.Season was an important factor affecting the vitamin D level of pregnant women Nanchong area.The vitamin D level in summer and autumn was higher than that in winter and spring and the vitamin D deficiency rate was lower.The relationship between pregnant women's age,number of pregnancies,number of deliveries and vitamin D levels are not clear.Therefore the vitamin D supplement should be strengthened in winter and spring.3.Vitamin D may be related to the occurrence of hypertensive disorders of pregnancy;The relationship between vitamin D and GDM and ICP was still unclear which needs further research.