Analysis Of The Correlation Between The Thyroid Function Index And Pregnant Outcomes

ObjectiveTo establish the percentile range of thyroid function during pregnancy in the Maternal and Child Health Hospital affiliated to Anhui Medical University and to investigate the prevalence of thyroid disease of pregnant women in our hospital.Based on the the recommendations of American Thyroid Association's thyroid function indicators in2011 and 2017 and the percentile range of thyroid function which self-established,the effects of abnormalities on pregnancy outcomes were explored in order to provide some advise for the reference value range and the current screening program.Methods1. Total of 4058 pregnant women?The group A?were selected from the obstetrics department of Maternal and Child Health Hospital affiliated to Anhui Medical University from January 2019 to June 2019.Then record the general information of the mother,screening status of thyroid function in each pregnancy,and information about childbirth.2. Group B include 1287 healthy and singleton pregnant women,which are selected from group A. we establish the percentile range of thyroid function indicators of the group B duiring the first trimester(12⁺⁶weeks)?the second trimester(13-27⁺⁶weeks)and the third trimester??28 weeks?among which the first trimester is divided into the first-first trimester(?6⁺⁶weeks)and the second-first trimester(7-12⁺⁶weeks).3.To calculate the prevalence rate of various thyroid diseases during pregnancy in group A according to the established percentile range of TSH and FT4 and ATA's guidelines in 2017.4.Based on the recommendations of the ATA's recommended thyroid function indicators in 2011 and 2017 and the percentile range of self-established thyroid function indicators,the relationship between abnormalities of each indicator and adverse pregnancy outcomes was explored in pregnant women in group C?based on the criteria in 2.1?.Result1.The percentile range of TSH for each trimester for pregnant women in our hospital based on group B are:0.55-4.49m IU/L,0.10-3.38m IU/L,0.17-3.89m IU/L,0.51-4.96m IU/L,the percentile range of FT4 are:0.62-1.13ng/dl,0.66-1.20ng/dl,0.44-0.84ng/dl,0.39-0.72ng/dl.2. the TSH level in the second-first trimester was the lowest,and TSH showed an upward trend in the second-first?the second,and the third trimester,which were statistically significant.There was no significant difference in TSH levels between the first-first and the third trimester?adjusted P>0.05?.There was no significant difference in FT4 levels between the first-first and second-first trimester?adjusted P>0.05?,both of which were higher than the second and the third trimester,and FT4 showed a downward trend with the trimester?both adjusted P>0.05?.3. Based on the established percentile intervals of TSH and FT4,the 2017 ATA guidelines,the prevalence of thyroid disease during pregnancy in group A of 4,058pregnant women was retrospectively diagnosed.Based on self-established percentile interval analysis,The prevalence rates of clinical hypothyroidism,subclinical hypothyroidism,clinical hyperthyroidism,subclinical hyperthyroidism,isolated hypothyroxinemia,and isolated TPOAb?+?were:0.20%,3.42%,0.59%,0.86%,2.54%,7.44%.When analyzed by the 2017 ATA guidelines,the prevalence of the above diseases is:0.25%,3.87%,0.49%,0.74%,3.20%,8.18%.There was no significant difference in the prevalence of various thyroid diseases under the two diagnostic criteria?P>0.05?.4. In the first and second trimester,when the recommended values of the ATA guidelines in 2011 and 2017 and the 97.5^thof the established percentile intervals were as the upper limits,the TSH increasing was not related to adverse pregnancy outcomes ?both P>0.05?.In third trimester,when taking 3.0m IU/L as the upper limit of TSH,TSH elevation does not increase the risk of adverse pregnancy outcomes;when taking 4 m IU/L and 97.5^thas the upper limit,the risk of abnormal pregnancy outcomes is increased by 1.766 times?95%CI 1.089-2.859,P<0.05?and 2.259 times?95%CI1.098-4.647,P<0.05?.5. Further analysing the specific adverse pregnancy outcomes.When taking 4m IU/L as the upper limit of TSH in the third trimester,pregnant women with TSH?4m IU/L have an increased risk of pregnancy-induced hypertension?OR=2.330,95%CI 1.395-3.893?,fetal distress?OR=2.342,95%CI 1.346-4.075?,premature?OR=2.642,95%CI 1.221-5.714?,fetal growth restriction?OR=5.947,95%CI 2.097-16.857?and low birth weight infants?OR=2.525,95%CI 1.175-5.427?.When taking the 97.5^th,which is 4.96m IU/L,as the upper limit,there is an increased risk of of pregnancy-induced hypertension ?OR=3.111,95%CI 1.600-6.010?,fetal distress?OR=3.542,95%CI 1.780-7.049?, premature?OR=3.542,95%CI 1.780-7.049?,fetal distress?OR=5.971,95%CI2.527-14.112?,stillbirth?OR=25.211,95%CI 1.394-455.980?,fetal growth restriction?OR=11.558,95%CI 3.662-36.480?and low birth weight?OR=5.400,95%CI 2.316-12.590?.6. When taking the 2.5^thof the percentile range and the lower limit provided by the kit as the lower limit of FT4,the decrease of FT4 in each pregnancy does not increase the risk of adverse pregnancy outcomes?P>0.05?.7. The TSH levels of TPOAb-positive pregnant women during the first and the second trimester were higher?P<0. 05?;there was no significant difference in TSH levels of TPOAb-positive and negative pregnant women during the third pregnancy?P>0.05?.There was no significant difference in the FT4 level of TPOAb-positive and negative pregnant women in each trimester?all P>0.05?.Binary logistic regression analysis showed that TPOAb positive in each trimester did not increase the risk of adverse pregnancy outcomes?all P>0.05?.ConclusionThe percentile range of thyroid function index established by our research is different from previous studies.This study shows that there is no correlation between the abnormal increase of TSH in the first or second trimester and adverse pregnant outcomes,we should pay attention to the thyroid dysfunction in third trimester which has an adverse impact on the outcomes of pregnancy.hypothyroxinemia and TPOAb positive were not correlated with adverse outcomes.