The baby can be had when hypothyroidism is detected in the third trimester of pregnancy. Combined hypothyroidism in pregnancy is a common endocrine disorder during pregnancy, which can increase the incidence of early and late pregnancy complications, such as gestational hypertension and placental abruption. If left untreated, it can also increase the incidence of fetal miscarriage, fetal growth restriction, intrauterine fetal death, fetal malformation and mental retardation, so treatment should be initiated as soon as hypothyroidism in pregnancy is detected. Levothyroxine treatment is generally preferred for hypothyroidism. After standardized treatment, the incidence of complications during pregnancy and the IQ index of the offspring are not significantly different from those of normal patients, and require medication adjustment and regular monitoring under the guidance of an endocrinologist or obstetrician.