Methyldopa is considered the antihypertensive of choice in pregnancy because it is safe for both mother and fetus. It works as a centrally acting alpha-2 adrenergic agonist, effectively lowering blood pressure without causing fetal harm. Unlike ACE inhibitors (e.g., lisinopril) and ARBs (e.g., losartan), which are teratogenic and contraindicated in pregnancy, methyldopa has a long history of use and extensive safety data. Beta-blockers like atenolol are generally avoided due to potential fetal growth restriction. Therefore, methyldopa remains the most rational and clinically recommended option for managing hypertension during pregnancy.

Reference: Harrison's Principles of Internal Medicine, J. Larry Jameson, 20th Edition.