Study On The Influencing Factors Of Hyperthyroidism In Very Premature And Mid-Term Premature Infants

Objective:To analyze the effects of factors such as small gestational age and maternal age on hyperthyroidism in very premature and mid-term premature infants in order to provide clinical reference.Methods:A total of 147 premature infants with gestational age of 28-33 weeks in neonatal intensive care unit(neonatal intensive care unit,NICU)of Cangzhou people’s Hospital from December 2018 to June 2020 were divided into two groups according to gestational age:109 cases of very preterm infants(gestational age 28-31 weeks)and 38 cases of mid-term preterm infants(gestational age 32-33 weeks).Serum thyroid function was measured at 2weeks,4 weeks,6 weeks and 10 weeks after birth,including TSH,FT4,FT3,TT4,TT3.A total of 49 premature infants with hyperthyroidism were found as the experimental group and 98 premature infants with normal thyroid function served as control group.The sex,gestational age,birth weight,whether the infant was smaller than gestational age and whether the mother was hypertensive complicating pregnancy were counted.Five results of serum thyroid function were collected each time,and the influencing factors and the changes of serum thyroid function were compared between the two groups.Results:1.Of the 147 preterm infants selected,49 developed hyperthyroidism(33.3%),including 30 very premature infants(61.2%)and 19 mid-term premature infants(38.8%).At 2 weeks after birth,the serum TSH values of 3children with hyperthyroidism were higher than 20 m U/L(22.94 m U/L,50.82 m U/L,39.66 m U/L,respectively).They were treated with oral levothyroxine sodium tablets.At 4 weeks after birth,a child with hyperthyroidism had a TSH value greater than 20 m U/L(24.17 m U/L)and was treated with oral levothyroxine sodium tablets.2.Univariate analysis showed that birth weight,gestational age,small gestational age and maternal hypertension were associated with hyperthyroidism in very premature infants(P<0.05),Gestational age and maternal age over 30 years old were associated with hyperthyroidism in mid-term premature infants(P<0.05).Multivariate analysis showed that birth weight(OR=0.063,95%CI:0.007-0.550)was an independent risk factor for hyperthyroidism in very premature infants(P<0.05),Maternal age over 30 years old(OR=17.318,95%CI:3.206-93.545)was an independent risk factor for hyperthyroidism in mid-term premature infants(P<0.05).3.There was no significant difference in serum TSH levels between very preterm and mid-term preterm infants at 2,4,6and 10 weeks after birth(P>0.05),but the levels of serum FT4 and TT4 in very preterm infants were significantly lower than those in mid-term preterm infants at 2 weeks after birth(P<0.05),and there was no significant difference in serum FT4 and TT4 levels at 4 weeks,6 weeks and 10 weeks after birth(P>0.05).The level of serum FT3 in very preterm infants was significantly lower than that in mid-term preterm infants at 2 weeks,4 weeks,6 weeks and 10 weeks after birth(P<0.05),but there was no significant difference in serum TT3 levels at2 weeks,4 weeks,6 weeks and 10 weeks after birth(P>0.05).Conclusion:1.Birth weight,gestational age,small gestational age infants and maternal hypertension are the influencing factors of hyperthyroidism in very premature infants.Birth weight is an independent risk factor for hyperthyroidism in very premature infants.2.Gestational age and maternal age are the influencing factors of hyperthyroidism in mid-term premature infants.Maternal age is an independent risk factor for hyperthyroidism in mid-term premature infants.