The influence of fallopian tube ampullary length on the fertility of the rabbit.

The relationship between length of the ampullary segment of the fallopian tube and degree of fertility was investigated in 22 New Zealand White rabbits subjected to the microsurgical resection of differing lengths of ampullar with preservation of the full isthmus. The correlation was poor (r = 0.33; P = not significant); the subsequent fertility being unpredictable from a given a length of remaining ampulla. These data are in contrast with those of our previous tubal resection study, where segments of proximal oviduct were excised (1). There, a linear correlation between length of oviduct remaining distally and degree of fertility was demonstrated. Possible reasons for the unpredictability of fertility after segmental resection of ampulla are discussed. Until human data are available, such animal data suggest that the length of distal tubal remnants may predict potential fertility better than the length of proximal tubal remnants. For this reason, a sterilization procedure might best be performed on the proximal oviduct (isthmus) to allow predictability of reversal of the procedure should the occasion arise.