The high level of alkaline phosphatase in the blood of pregnant women after 37 weeks of pregnancy may be due to physiological reasons. Alkaline phosphatase is an enzyme that is excreted from some tissues of our body through the liver to the bile, and this enzyme can be divided into several different isozymes, which means that there are several different branches of this enzyme. One of the alkaline phosphatase enzymes is secreted by the placenta, so it is possible for a pregnant woman to have an increase in alkaline phosphatase under physiological conditions. If a pregnant woman has an increase in this enzyme during a maternity visit, but there are no clinical symptoms and the alkaline phosphatase does not change much during the monitoring process, there is no need to worry too much. However, in patients with skeletal, hepatobiliary, and thyroid diseases, elevated enzymes can also occur and require attention.