During which term of pregnancy are ALP levels 2 to 3 fold higher than the upper reference limit?

Alkaline phosphatase (ALP) levels are significantly elevated during the third trimester of pregnancy, often reaching 2 to 3 times higher than the upper reference limit. This increase is primarily attributed to the production of ALP by the placenta, which is more pronounced as pregnancy progresses. During this time, the developing placenta and fetal tissues contribute to the elevated levels of Alkaline phosphatase, particularly in the last trimester, making it a vital period for monitoring these enzyme levels in relation to maternal health.

In the earlier trimesters, specifically the first and second trimesters, ALP levels do not typically rise to this extent. Although some increase may occur during the second trimester due to the growing placenta, it does not reach the significant elevations seen in the third trimester. Consequently, while there can be variations in ALP levels throughout pregnancy, the most marked elevation occurs during the final term.