Study On The Relationship Between Vitamin D Levels And Premature Delivery In Pregnant Women

Objective:To understand the maternal vitamin D (VD, VitD) level and explore the relationship between preterm birth and VD level through the detection of full-term pregnant women and premature delivery women’s VD levels.Methods:102 cases were collected from pregnant women who were hospitalized in department of obstetrics of the second affiliated hospital of Kunming medical university from 2014 May to November. Questionnaire survey, ruled out 22 maternal women who chose elective cesarean section without starting production process, had a history of metabolic disease, liver and kidney disease, long-term diarrhea or medication. Selected 80 cases of pregnant and delivery women as the research object, including 50 cases of full-term pregnant women,30 cases of premature delivery women. Selected venous blood 3ml from the maternal woman when she gave birth to the child, and selected the umbilical cord blood 3ml from the corresponding neonatal (50 samples of full-term infants were selected, only 20 samples of preterm infants were selected because of serious illness and other reasons).Using tandem mass spectrometry hy-phenated to liquid chromatography systems to test maternal and neonatal serum 25-(OH) D levels, compared the difference between the full-term pregnant women and premature delivery women in the level of serum 25-(OH) D.Results:1.80 cases of pregnant and delivery women generally lack of VD, serum 25-(OH) D mean of 26.68±9.99 ng/ml, lower than the foreign scholars have put forward 30 ng/ml adult vitamin D standard; according to the adult VD standard, only 31 women’s VD levels were in the normal range, accounting for 38.8% of the survey, the rest 61.2% of the survey were of VD deficiency in different degrees; 50 cases of full-term pregnant women,60% lack of VD,30 cases of premature delivery women,63.3% lack of VD.2. The mean (13.64±5.95 ng/ml) of 70 cases of neonatal serum 25-(OH)D is lower than the foreign scholars have put forward 20 ng/ml children VD adequacy standards. According to the children VD standard, only 17.1% of the neonatals’ VD levels were in the normal range, the left 82.9% of the neonatals were of VD deficiency in different degrees.3.50 cases of full-term pregnant women’s serum 25-(OH)D(mean 27.00±9.14 ng/ml) is slightly higher than the serum 25-(OH)D(mean 26.15±11.42 ng/ml) of 30 premature delivery women, but the difference was not statistically significant (P>0.5).4.20 cases of premature infants serum 25-(OH) D (mean 13.90±6.90 ng/ml) and 50 cases of full-term infants serum 25-(OH) D (mean 13.43±5.57 ng/ml) had no significant difference (P> 0.05).5. The neonatal serum 25-(OH) D and pregnant and delivery women serum 25-(OH) D showed a significant positive correlation (r=0.708, P=0.000).6. VD supplementation time in pregnancy and maternal serum 25-(OH) D level has significant correlation, namely VD supplementation time in pregnancy is longer, serum 25-(OH) D level is higher. The time in the sun during pregnance, nationality, education, occupation showed no significant effect of VD level.7.16 pregnant women with pregnancy complications in 80 samples. The prevalence rate of pregnancy complications in premature delivery women is 33.3%, while the rate is 12% in full-term pregnant women, premature delivery women’s pregnancy complication rate is higher than that of full-term pregnant women (P< 0.05). The serum 25-(OH) D (mean 27.656±11.3643 ng/ml) of 16 women with pregnancy complications compare with the serum 25-(OH) D (mean 26.441±9.7018 ng/ml) of 64 women without pregnancy complications showed no significant difference (P> 0.05).Conclusion:1. Pregnant and delivery women and neonatals’ serum 25-(OH) D levels were short, lower than the standard proposed by foreign scholars.2. There was no obvious correlation between the VD deficiency and premature delivery.3. VD supplementation time in pregnancy has a significant effect on maternals’serum 25-(OH) D levels. The time in the sun during pregnance, nationality, education, occupation showed no significant effect of VD level.4. Premature pregnancy complication rate is higher than that of full-term pregnant women. But the occurrence of pregnancy complications, neither term nor preterm labor, there was no obvious correlation between the serum VD levels.