Thyrotropin level in 31 weeks of pregnancy is 5.1mIU/L , which is usually not serious, pregnant women usually need to ensure enough rest and go to the hospital regularly for maternity checkups. Thyrotropin is a hormone secreted by the pituitary endocrine command, mainly to help manage and dominate the size of the thyroid gland as well as synthesize and secrete thyroid hormones. For most of the thyroid stimulating hormone is a little high, usually need to review regularly, there is no special need to diet and take medication. Generally normal people draw blood through the chemiluminescence method to detect the thyrotropin content, the normal range is usually in the 0.35 ~ 5.5mIU / L , so 31 weeks pregnant body thyrotropin content of 5.1mIU / L , did not exceed the qualifying value, generally not serious. Although the serum thyroid stimulating hormone level of 5.1mIU/L is within the normal range, but pregnant women are prone to subclinical hypothyroidism in the late stages of pregnancy, pregnant women need to go to the hospital on a regular basis for obstetrics, to clarify whether the thyroid function is normal. During pregnancy, pay attention to rest, and should relax, avoid tension, anxiety, any discomfort should be timely to the hospital, the doctor to clarify the diagnosis, and cooperate with the doctor to deal with the symptoms.