16. Pregnant (positive pregnancy test) or nursing women. Angiogenesis is critical to fetal development and the inhibition of angiogenesis following administration of AVASTIN is likely to result in adverse effects on pregnancy. There are no adequate and well-controlled studies in pregnant women. Both fertile men and women must agree to use adequate contraceptive measures during study therapy and for at least 2 months after the completion of bevacizumab therapy.