Influence Of Hypothyroidism And Positive TPOAb On Pregnancy Outcomes During Early Pregnancy

Objective: To investigating the influence of maternal subclinical hypothyroidism、TSH which range from 2.5u IU/ml to upper limit of specific reference in early pregnancy and positive anti-thyroid peroxidase antibody(TPOAb)on the pregnancy outcomes.Methods: A total of 3268 pregnant women undergoing the first prenatal examination in our hospital and Jiangdong Maternity Health Hospital were enrolled during the period from February 2014 to May 2016.Chemiluminescence method was used to determine the free thyroxine(FT4),anti-thyroid peroxidase antibody(TPOAb)and thyrotropin(TSH)levels.By establishing the pregnancy-specific reference ranges of TSH、FT4 in early pregnancy(TSH0.09-5.28 u IU/ml,FT412.91-22.35 pmol/L)。(1)subclinical hypothyroidism(SCH)group:TSH>5.28 u IU/ml,FT412.91-22.35 pmol/L;(2)TSH increase group:TSH2.5-5.28 u IU/ml,FT412.91-22.35 pmol/L;(3)control group:TSH<2.5u IU/ml,FT412.91-22.35 pmol/L,TPOAb was negative.Each group was divided into two subgroups by positive or negative TPOAb.To analyze the results of thyroid function,TPOAb in different subgroups and their effects on pregnancy outcome.Results:(1)The prevalence of hypothyroidism and subclinical hypothyroidism and positive TPOAb.Among the 3268 cases in early pregnancy,the prevalence rate hypothyroidism was 0.52%(17/3268),and the prevalence rate of subclinical hypothyroidism was 2.8%(92/3268).There were 605 cases in TSH increase group,with the incidence of 18.5%(605/3268).370 cases had positive TPOAb,with the incidence of 11.3%(370/3268).(2)The relationship between thyroid function and TPOAb.63 TPOAb-positive cases were in the SCH group,and the incidence of SCH was 17.0%(63/370).There were 29 TPOAb-negative cases in the SCH group,with the incidence of 1.0%(29/2898).The difference was statistically significant(P<0.01).198 TPOAbpositive cases were in the TSH increase group,and its incidence was 32.7%(198/605).There were 407 TPOAb-negative cases in the study observed group,with the incidence of 67.3%(407/605).The difference was statistically significant(P<0.01).(3)Comparison of pregnancy outcomes between the SCH group and the TSH increase group to the control group: The incidence of premature delivery,miscarriage,low-birth-weight infants was 4.3%(4/92)、5.4%(5/92)、5.4%(5/92),1.1%(1/92),respectively in the SCH group.Those in the TSH increase group was 3.3%(20/605)、 3.8%(23/605)、 3.3%(20/605)、 0.8%(5/605).And those in the control group was 1.9(48/2480)、 2.2%(56/2480)、 1.9%(47/2480)、0.6(14/2480).The differences were statistically significant(P<0.05).While there was no statistically significant difference in the incidence of placental abruption among the three groups.(P >0.05).(4)Comparison of pregnancy outcomes between the positive TPOAb and the negative TPOAb in each group.The incidence of premature delivery and low-birth weight infants in the TPOAb positive cases of the SCH group had statistically significant difference(P <0.05)when compared with TPOAb negative cases.While the incidence of miscarriage and placental abruption had no statistically significant difference(P>0.05).The incidence of miscarriage,premature delivery and low-birth weight infants in the TPOAb positive cases of the TSH increase group had statistically significant difference(P <0.05)when compared with TPOAb negative cases and the control group.While the incidence of placental abruption had no statistically significant difference(P>0.05).The incidence of premature delivery and low-birth weight infants in the TPOAb positive cases of the SCH group had no statistically significant difference(P <0.05)when compared with TPOAb negative cases。Conclusion: The incidence of miscarriage,premature delivery and low-birth weight infants in the TPOAb positive cases of the TSH increase group had statistically significant difference(P <0.05)when compared with TPOAb negative cases and the control group.While the incidence of placental abruption had no statistically significant difference(P>0.05).