Associations Between 25-hydroxyvitamin D Levels And Pregnancy Outcomes

ObjectiveThe aim was to assess maternal 25(OH)D status and its associtation with pregnancy outcomes.To provide guidance for how to guide reasonable vitamin D supplements during pregnancy.MethodsPregnancy women(n=3165)was recruited at a teaching hospital from October 2015 to September 2016.Maternal 25(OH)D levels were measured at before 13 week gestation、22-24 week gestation and 32-34 week gestation.The pregnancy women if met inclusion and exclusion criteria,were erollded in further analysis for pregnancy outcomes(n=447).Result1.The three mean serum 25(OH)D levels were(19.97±6.57ng/mL,24.66±7.29ng/mL,27.64 ± 7.92 ng/mL),P < 0.05.in the first,second and third trimester of pregnancy.2.In the first trimester of pregnancy the 25(OH)D rates were 53%,39%,31% in low level,medium level and high level.In the second trimester of pregnancy the25(OH)D rates were 27%,51%,22% in low level,medium level and high level.In the third trimester of pregnancy the 25(OH)D rates were16%,47%,37% in low level(≤20ng/ml),medium level(21-30 ng/ml)and high level(≥30 ng/ml).3.In the first trimester of pregnancy the average serum 25(OH)D levels of diferent seasons were(winter = 18.34±6.14ng/mL,spring =18.89±5.96 ng/mL,summer=22.51±6.55 ng/mL,autumn =21.87±8.29 ng/ml P<0.001).Maternal 25(OH)D was highest in summer(22.51±6.55ng/ml)and lowest in winter(18.34±6.14ng/ml)(p <0.001).The seasonal variation in serum 25(OH)D concentration were fhe same in secondand third trimesters.4.Most materal outcomes(premature rupture of membranes break,gestional diabetes,hytertensive disorders in pregnancy,preterm delivery,Caesarean section,and anemia during pregnancy)and neonatal outcomes(fetal distress)were not significantly different between groups.But in the second trimester of pregnancy the bacterial vaginosis incidence were 7.34%(8/109),4.55%(9/198),13.79%(12/87)in each group.The bacterial vaginosis in high level group(25(OH)D≥30ng/ml)was higher than that in low and medium groups.Conclusion1.The three mean serum 25(OH)D levels were(19.97±6.57ng/mL,24.66±7.29ng/mL,27.64±7.92 ng/mL),Vitamin D deficiency during pregnancy is common,along with the increase of gestational age,the serum 25(OH)D levels also increase.2.As the age,pregnancy rate and delivery times increases the Vitamin D levels also increases,particularly in the first and second trimester of pregnancy.3.The average of serum 25(OH)D levels are differents in differernt seasons.The average of serum 25(OH)D levels were higher in summer and autumn than that in winter and spring,Therefore,we can increase vitamin D supplementation in winter and spring seasons.4.There were no significant differences in most adverse pregnancy outcomes among pregnancy women with different levels of vitamin.5.There is no domestic evaluation of serum vitamin D level standards at present,this research filled different range of 25(OH)D values during pregnancy in our hospital and provide certain reference significance for clinical vitamin D supplements.