- AZD2171 has been shown to terminate fetal development in the rat, as expected for a process dependent on vascular endothelial growth factor (VEGF) signaling; for this reason, women of child-bearing potential must have a negative pregnancy test prior to study entry; women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation; should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately