| Objective: Thyroid hormone is involved in regulating the metabolism of proteins,lipids and carbohydrates,is the key regulator of metabolism,development and growth,promotes the brain and growth of the fetus,and can affect the metabolism of blood lipids in pregnant women.Mild maternal thyroid function changes in the early or second trimester of pregnancy,including subclinical hypothyroidism and hypothyroidism,affect the growth and development of offspring to varying degrees.Fetuses and newborns have great plasticity and the ability to change the level of gene expression through epigenetic modification to respond to environmental factors(nutrition,oxygen,hormones).The purpose of this study was to study the effects of thyroid hormone and blood lipid levels on pregnancy outcome by large sample epidemiology.From the point of view of epigenetics,taking DNA methylation as the starting point,this paper explores the effects of the changes of total genome methylation in maternal peripheral blood and umbilical cord blood on their offspring,and reveals the change pattern of epigenetics affected by hormones.Methods:1.From January 2018 to December 2018,a total of 10574 pregnant women were selected from the International Peace Maternal and Child Health Hospital affiliated to the Medical College of Shanghai Jiaotong University and the Shanghai Songjiang District Maternal and Child Health Hospital to establish perinatal health care files.To analyze the correlation between thyroid hormone and blood lipid level at 12-16 weeks of gestation,and its effect on pregnancy outcome.2.50 cases of subclinical hypothyroidism and 50 cases of normal thyroid function were collected.Peripheral blood and umbilical cord blood were collected during delivery.ELISA method was used to detect the overall methylation level of DNA in peripheral blood and umbilical cord blood of pregnant women.The relationship between TSH,FT4,FT3 or TG and TC was studied by linear regression model.The potential nonlinearity is evaluated by residual graph,and the hypothesis of the model is tested.T-test was used to test the methylation of maternal and umbilical cord blood.Result :1.Serum FT4 levels were negatively correlated with TG and TC levels in pregnant women,while higher levels of FT3 were positively correlated with TG and negatively correlated with TC(all P < 0 05).There was a negative correlation between maternal TSH level and TG level,but no significant difference between maternal TG level and TC level(P > 0.79).2.In pregnancy outcome,the levels of serum TSH and FT4 decreased,the levels of T3,FT3,TG and TC increased in gestational diabetes mellitus group,and the levels of FT3 and TG increased in hypertensive disorder complicating pregnancy.The level of TSH in pregnant women with placental abruption increased,the level of serum TC in women with premature rupture of membranes increased,and the level of serum TG in pregnant women with premature delivery increased(all P < 0 05).3.In pregnancy outcome,the levels of serum TSH and FT4 decreased,the levels of T3,FT3,TG and TC increased in gestational diabetes mellitus group,and the levels of FT3 and TG increased in hypertensive disorder complicating pregnancy.The level of TSH in pregnant women with placental abruption increased,the level of serum TC in women with premature rupture of membranes increased,and the level of serum TG in pregnant women with premature delivery increased(all P < 0 05).4.There was significant difference in the whole genome methylation level of maternal peripheral blood between the subclinical hypothyroidism group and the normal thyroid function group(P > 0.05),but there was no significant difference in umbilical cord blood(P < 0.05).Conclusion:Reasonable control of thyroid hormone and blood lipid levels can improve the effect of maternal and fetal outcome and reduce the risk of SGA,LGA and macrosomia.Epigenetic changes may be one of the pathological mechanisms of poor pregnancy outcome in pregnant women with decreased thyroid function during pregnancy. |
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