On the contrary, if a pregnant woman is diagnosed with hypothyroidism during pregnancy, if she does not apply Eugenol treatment in time, it will have adverse effects on the pregnant woman and the fetus, which may lead to pre-eclampsia, placental abruption, fetal miscarriage, malformation, fetal growth restriction, and fetal mental development disorder, and even lead to fetal death. Therefore, when a pregnant woman is diagnosed with clinical hypothyroidism during pregnancy, she should take the medication according to the dosage and on time, and should review the thyroid function regularly to adjust the dosage in time to reduce the adverse effects of hypothyroidism on the fetus and the pregnant woman.