Monkeys (n = 8) were treated with 3 COS protocols and assigned randomly to groups as follows: 1) COS alone (Control, n = 5); 2) COS + VEGF mAb Avastin 19 ± 5 h before hCG (Avastin pre-hCG; n = 6); 3) COS + Avastin 3-4 days post-hCG (Avastin post-hCG; n = 4); 4) COS + Simulated Early Pregnancy (SEP n = 3); or 5) COS + SEP + Avastin (SEP + Avastin n = 3).