The Combined Effect Of Maternal Mild Hypothyroidism And Emotional Symptoms On Adverse Pregnancy Outcomes During The First And Second Tirmester: A Population-based Cohort Study

Objectives To describe the level and status of thyroid hormones in pregnant womenduring the first and second trimester from Ma’an shan city, An hui province. To analysisthe risk factors of mild hypothyroidism. The aims of this study was also to explore thecombined effect of maternal mild hyperthyroidism and emotional symptoms to adversepregnancy outcomes including preterm labor、small for gestational age infant、congenital heart disease and etc.Methods In our population-based birth cohort study, the subjects were pregnant womenwho had their first prenatal examination and signed informed consent voluntarily atMaternity and Child Care Centers in Ma’an shan from October2008to October2010.The information about pregnant women including socio-demographic characteristics,lifestyle behavior, history of pregnancy and psychosocial stress are collected fromMaternal Basic Information Collection Form by them with the guidance of trainingdirector. Doctors of clinical laboratory collected5ml peripheral venous blood frompregnant women when they had their first prenatal examination and preserved in lowtemperature environment after centrifugation. Using Luminescence Immunoassay tomeasure the level of maternal thyroid hormones after pregnant women gave birth totheir children. The measurement indexes are thyroid stimulating hormone (TSH), freethyroxine (FT4) and thyroid peroxidase antibody (TPO-Ab). To collect pregnant outcomes information by Maternal and Birth Outcomes Collection Form andPopulation-based Birth Defect Registration Card. Gestational specific thyroid referenceranges were made by percentile method through Statistical Product and ServiceSolutions versions13.0(SPSS13.0). The distribution of maternal thyroid function, theinfluencing factors of thyroid function, the association between maternal mildhypothyroidism in pregnancy and pregnant outcome and the combined effect of mildmaternal hypothyroidism and emotional symptoms to adverse pregnancy outcomes wereanalyzed by Chi-square and non-condition logistic regression.Results Sociodemographic、emotional symptoms and other related informations of5084pregnant women of Ma’an shan city in An hui province were collected fromOctober2008to October2010. There were totally4805pieces of valid questionnairesand4602serum samples. The final number of subjects were3343after ruled out thosepregnant women who got twins, at the third trimester at her first prenatal examinationand whose serum weren’t used for the thyroid hormone test.We used the percentile method to access maternal thyroid function every four weeks asa period. There were totally938pregnant women who got mild hypothyroidismincluding subclinical hypothyroidism, hypothyroxinemia and TPO-Ab positive in3443pregnant women. Before the gestational age of20, maternal TSH levels did not go upobviously or even went down lightly, after that, the rising trend had become moreapparent. While the levels of FT4were in a flat or slightly downward trend, the overalltrend was declined.We used T test to compare the birth index of offspring between the maternal mildhypothyroidism group and normal group. The results indicated that there weresignificantly statistic differences on head and chest circumference of offspring in thegroup of SCH and hypothyroxinemia. Compared with the normal thyroid functiongroup, the children of those maternal with SCH were more likely to suffer from congenital heart disease (OR=3.24,95%CI：1.11-9.45); maternal TPO-Ab positivegroup were more likely to have birth defects and gestational hypertension.Among participants without pregnancy-related anxiety, maternal TPO-Ab positivegroup were significantly associated with gestational hypertension both before(RR=2.73,95%CI：1.29-5.80) and after (RR=2.74,95%CI：1.45-5.33) adjustment (RRof them were2.73、2.74，95%CI of them were1.29-5.80、1.14-5.33).Among maternalhypothyroxinemia group, pregnant women with pregnancy-related anxiety were morelikely to suffer from gestational diabetes mellitus than those without it. Thecombination of hypothyroxinemia、TPO-Ab positive and pregnancy-related anxietycan increase the risk of gestational hypertension and gestational diabetes mellitus (Pvalue <0.05).Conclusions Maternal with mild hypothyroidism can increase the risk of adversepregnancy outcomes, the combination of mild hypothyroidism and emotional symptomscould increase the risk of pregnancy complications. Therefore, formulate specific indexreference range for thyroid function during pregnancy with consideration of emotionalsymptoms is useful for screening and treatment of thyroid dysfunction. and can producepositive effects on improving relevant care instruction on prevention of adversepregnancy outcomes of daily work.