- Pregnant women (positive pregnancy test) are excluded from this study because bevacizumab is an anti-angiogenic agent with the potential for teratogenic or abortifacient effects; because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with bevacizumab, breastfeeding should be discontinued if the mother is treated with bevacizumab; both fertile men and women must agree to use adequate contraceptive measures during study therapy and for at least 6 months after the completion of bevacizumab therapy; abstinence is considered an adequate contraceptive measure