Correlation Analysis Between Isolated Maternal Hypothyroxinemia And Pregnancy Outcomes

ObjectiveTo analysis the relationship between Isolated maternal hypothyroxinemia(IMH)and various adverse pregnancy outcomes.MethodA retrospective study of 313 subjects was conducted.All subjects were selected from the Department of Obstetrics and Gynecology of The Second Affiliated Hospital of Fujian Medical University between January 2017 and January 2018.Subjects were classified into two groups: Group A(normal group,n=151)with FT3,FT4 and TSH values in the normal range,and Group B(IMH group,n=162)with TSH and FT3 values in the normal range and FT4 value<12pmol/L.The general information and measures of thyroid hormone,thyroid autoantibody determination,routine biochemistry and routine blood work were collected for statistical analysis.All subjects had TSH and thyroid autoantibody levels in the normal reference range.SPSS25.0 software was used for statistical analysis of the data.T-test,χ2-test and Kruskal-Wallis H test were used for mean comparison between the two groups.Finally,logistic regression analysis was used to analyze the correlation between FT4 level and pregnancy outcomes.Results1.There were a total of 313 eligible subjects in this study,which were divided into two groups according to thyroid function test values: group A(normal group,n=151): with an average age of 31.69±0.39 years and an average weight of69.33±0.81 kg and an average gestational weeks of 38.00±1.24 weeks.Group B(IMH group,n=162): with an average age of 32.41±0.36 years and an average weight of 72.36±0.63 Kg and an average gestational weeks of 37.67±1.69 weeks.There was no significant difference in the general data of age and weight between the two groups(P >0.05),and the frequency distribution was basically normal and comparable.2.The difference of gestational diabetes mellitus between group A(normal group)and group B(IMH group)was statistically significant(p<0.05).However,there was no significant difference between group A(normal group)and group B(IMH group)in delivery mode,premature delivery,abnormal placental amniotic fluid,gestational hypertension,postpartum hemorrhage,intrapartum hemorrhage,anemia,fetal sex,and fetal complication(p>,0.05).3.Finally,IMH was set as the independent variable,which was put into the Logistic regression equation for analysis.The results showed that IMH was an independent risk factor for gestational diabetes mellitus(p=0.023).And IMH was not an independent risk factor affecting the mode of delivery,premature delivery,abnormal placental amniotic fluid,gestational hypertension,postpartum hemorrhage,intrapartum hemorrhage,anemia,fetal sex,and fetal complication(p>0.05).The incidence of gestational diabetes mellitus in IMH was 1.912 times higher than that in normal pregnant women(OR=1.912).ConclusionsThe prevalence of gestational diabetes mellitus was significantly higher in women with hypothyroidemia in the third trimester of pregnancy.The incidence of gestational diabetes mellitus in IMH was 1.912 times higher than that in normal pregnant women(OR=1.912).Hypothyroidemia in the third trimester of pregnancy is a high risk factor for gestational diabetes mellitus.At the same time,hypothyroidemia in the third trimester of pregnancy was not significantly associated with the pregnancy delivery mode,premature delivery,abnormal placental amniotic fluid,gestational hypertension,postpartum hemorrhage,intrapartum hemorrhage,anemia,fetal sex,and fetal complication,but further studies were needed to confirm this.