Correlation And Influencing Factors Of Blood Bone Metabolism Biochemical Indicators Between Neonates And Pregnant Women

Objective To investigate the status quo of serum bone metabolism biochemical indexes of pregnant women with twin pregnancies before delivery and newborn twins in our hospital,analyze the correlation between the two,and further explore the related factors affecting serum 25-（OH）D₃levels in newborn twins.Methods A retrospective study was conducted to collect the birth information,basic information of pregnant women and pregnancy related information of twins with mild symptoms admitted to the neonatology Department of the Affiliated Hospital of Inner Mongolia Medical University from January 1,2018 to June 30,2022.And the fasting serum bone metabolism biochemical indexes of pregnant women with twin pregnancies 1 month before delivery and newborn twins 3 days after birth.Correlation analysis of serum bone metabolism biochemical indexes of pregnant women with twin pregnancies and newborn twins and the influencing factors analysis of serum 25-（OH）D₃level of newborn twins were conducted.Results A total of 302 pregnant women with complete data and 604 newborns with mild twins were included in this study.Specific results were as follows:1.302 women with twin pregnancies had an average blood calcium level of[2.1（2.0,2.3）]mmol/L,an average blood phosphorus level of[1.2（1.1,1.4）]mmol/L and an average alkaline phosphatase level of[132.5（106.0,167.0）]U/L at the end of pregnancy.The average level of 25-（OH）D₃was[15.4（13.2,17.0）]ng/ml,among which 8 cases（2.7%）were adequate,19 cases（6.3%）were insufficient,and 275 cases（91.0%）were deficient.2.604 mild twin newborns had an average venous calcium level of[2.0（1.8,2.1）]mmol/L,an average phosphorus level of[1.8（1.7,2.0）]mmol/L,and an average alkaline phosphatase level of[168.0（142.0,202.0）]U/L.The average level of 25-（OH）D₃was[12.2（9.1,16.4）]ng/ml,including 8 cases（12.3%）of adequate 25-（OH）D₃,66 cases（38.9%）of insufficient 25-（OH）D₃,339 cases（17.2%）of insufficient 25-（OH）D₃and 191 cases（31.6%）of severe 25-（OH）D₃deficiency.3.The level of serum 25-（OH）D₃was insufficient or deficient in most pregnant women and their newborns（97.3%of pregnant women and 87.7%of newborns）,and only 2.7%of pregnant women and 12.3%of newborn twins had adequate serum 25-（OH）D₃.4.The levels of blood phosphorus（r=0.171,P=0.000）and 25-（OH）D₃（r=0.128,P=0.002）in pregnant women with twin pregnancies were positively correlated with the levels of blood phosphorus and 25-（OH）D₃in newborns.5.The selected mild twins were grouped according to gestational age,and it was found that the blood phosphorus level of pregnant women in the gestational age group<34 weeks was positively correlated with the blood phosphorus level of newborns（r=0.171,P=0.032）.The serum phosphorus（r=0.261,P=0.000）,alkaline phosphatase（r=0.173,P=0.010）and serum 25-（OH）D₃（r=0.158,P=0.001）levels of pregnant women with gestational age≥34weeks were positively correlated with the serum phosphorus,alkaline phosphatase and serum25-（OH）D₃levels of newborns.6.The selected mild twins were grouped according to birth weight,and it was found that the blood phosphorus level of pregnant women in the birth weight<2500g group（r=0.258,P=0.000）and the birth weight≥2500g group（r=0.326,P=0.001）was positively correlated with the blood phosphorus level of newborns.In addition,there was a positive correlation between serum 25-（OH）D₃levels in pregnant women with birth weight<2500g and neonatal serum 25-（OH）D₃levels（r=0.291,P=0.000）.7.The levels of serum calcium（r=0.617,P=0.000）,phosphorus（r=0.379,P=0.000）,alkaline phosphatase（r=0.533,P=0.000）and 25-（OH）D₃（r=0.295,P=0.000）were positively correlated between the two twins born from the same mother.There were significant differences in serum calcium and phosphorus levels between the two groups（P<0.01）.8.Univariate analysis showed that the serum 25-（OH）D₃level of twins was correlated with gestational age of newborns,gestational times,delivery times,sun exposure time during pregnancy and 25-（OH）D₃level of pregnant mothers（P<0.05）.9.Multivariate analysis showed that maternal birth time and maternal 25-（OH）D₃level were the influencing factors of serum 25-（OH）D₃level in twins（P<0.05）.10.There were no significant differences in neonatal sex,gestational age,birth weight,birth season,maternal age,ethnicity,delivery mode,pre-delivery BMI and gestational BMI increase on serum 25-（OH）D₃levels in twins（P>0.05）.Conclusions1.The levels of serum 25-（OH）D₃in twins and their newborns were generally low.2.The blood phosphorus and 25-（OH）D₃levels of pregnant women with twin pregnancies were positively correlated with those of newborns.3.The serum phosphorus,alkaline phosphatase and serum 25-（OH）D₃levels of newborns in the gestational age≥34 weeks group were positively correlated with the serum phosphorus,alkaline phosphatase and serum 25-（OH）D₃levels of their mothers.4.Compared with the birth weight>2500g group,there was a positive correlation between the serum 25-（OH）D₃level of the pregnant women with twin pregnancies and the newborn in the birth weight<2500g group.5.Serum calcium,phosphorus,alkaline phosphatase and 25-（OH）D₃levels were positively correlated between twins born to the same mother.6.Maternal birth time and maternal 25-（OH）D₃levels affect serum 25-（OH）D₃levels in twins.