Effect of 4-Amino-Pteroylglutamic Acid (Aminopterin) on Early Pregnancy.

Abstract
The effect of 4-amino-pteroylglutamic Acid (Aminopterin) on fetal development was studied using mature Sprague-Dawley and Wistar rats and CFW mice. The animals were injd. with 3 consecutive doses of 0.15 mg./kg. in mice and 0.1 or 0.15 mg./kg. in rats at intervals of either 12 or 24 hrs. The injns. were started from the 5th or 7th day after mating. Aminopterin was lethal to the early embryo of mice and rats. Fetal death was observed with doses which temporarily caused depletion of the bone marrow but no other significant signs of intoxication in mothers.