Nonsurgical recovery of uterine embryos in the baboon

A nonsurgical technique is described for the recovery of baboon eggs using an Isaacs endo-metrial cell sampler modified for continuous medium flow. After gentle insertion of the catheter through the undilated cervix, 10 ml of warm medium is injected at the rate of 1 to 2 mI/mm and collected into a 15 ml tube. Thirty.seven eggs have been recovered from 80 flushes (46%) on 33 baboons. The recovery rate has increased with additional experience; 23 eggs have been obtained from the last 40 flushes (57.5%) compared with 14 from the first 40 (35%). Eggs have been re-covered from five successive flushes in one animal, and 18 eggs have been recovered from 24 flushes (75%) on four animals. Successful recoveries were performed 0 to 6 days after sex skin detumescence, indicating that the unfertilized baboon egg does not degenerate immediately after entering the uterus. Twenty-one eggs have been recovered from flushes during 44 mated cycles (48%) on 21 animals, and of these 14 (67%) were fertilized. Developmental stages of recovered embryos ranged from 4-cell to expanding blastocyst