Ovum transport after microsurgical anastomosis of the rabbit oviduct.

From experimental work in rabbits it is known that pregnancy outcome is influenced unfavorably by tubal resection anastomosis in spite of the preservation of tubal patency. In 104 Dutch belted rabbits the impact of microsurgical resection anastomoses on ovum transport during the first 24 hours after ovulation was examined. In oviducts in which the ampulla had been operated on, ovum transport was delayed. Mucosal irregularities that interfere with normal ampullary transport by cilia activity may account for the delay noted. Alterations in the duration of ovum transport in the oviduct may influence pregnancy outcome by creating an inappropriate tubal environment for the early embryo or by creating asynchrony between the embryo and the endometrium. No changes were observed in transport in oviducts in which the isthmus had been operated on: even a small segment of isthmus seems to act as a physiologic sphincter and to prevent premature ovum entrance into the uterus.