Patients with hypothyroidism have low secretion of thyroid hormones and slow metabolism, resulting in common “subhealth” symptoms such as low energy, memory loss and weight gain. Because the initial symptoms are mild, hypothyroidism is often overlooked by the public. Middle-aged and elderly people may mistake it as a manifestation of aging, while middle-aged and young people tend to think that they are “sub-healthy” and under stress at work, resulting in failure to seek timely medical attention. According to statistics, the average time of misdiagnosis of hypothyroidism is 5-7 years, which potentially threatens human health and leads to mucinous edema and arteriosclerosis in many organs of the body, which is life-threatening in serious cases. On average, 1 in 6 women are suffering from hypothyroidism. Even more frightening is the fact that if the patient is pregnant, the probability of miscarriage and fetal mortality in late pregnancy increases dramatically, and it is very likely to lead to impaired mental development and growth disorders in newborns, causing irreparable damage to both mother and child. Therefore, women should have their thyroid function routinely checked before pregnancy or consult an endocrinologist. Hypothyroidism can be treated very well and can be fully restored to normal levels by supplementing with physiological doses of thyroid hormones without affecting life and work, but long-term or even lifelong replacement therapy is required. Timely and effective treatment can significantly reduce the incidence and severity of obstetric complications and ensure the normal development of the newborn’s intelligence. Therefore, it is important for women with hypothyroidism to see an endocrinologist to adjust TSH to 2.50 mlU/L before pregnancy.