Reversible contraceptive effect of the oviduct plug with nickel–titanium shape memory alloy and silicone rubber in rabbits

BackgroundThe aim of this study was to observe the contraceptive effectiveness and reversibility of the oviduct plug with nickel–titanium (Ni-Ti) shape memory alloy and silicone rubber in rabbits.Study DesignThe oviduct plugs with Ni-Ti shape memory alloy and silicone rubber were made as contraceptive devices. The frame of the oviduct plug is made of silicone rubber and Ni-Ti shape memory alloy wire. The central part of the frame resembles a circular cylinder and the amphi-terminal of the frame is like a spigot which is formed with three mounting rings. Thirty-five New Zealand adult female rabbits were randomly divided into three groups. Thirty rabbits in Group 1 were used to test the contraceptive effect of the oviduct plug. Ten rabbits in Group 2 were used to assess the reproductive reversibility of the rabbits; 3 months after the operation, the oviduct plugs were removed from the junction of the uterus and tubes by incision of the abdomen. Another five rabbits (Group 3) served as the control group. In 30 female rabbits (Group 1), the plugs were inserted into the oviducts via a 0.5-cm incision of the uterus by using an inserter that contained the plug, then the female rabbits copulated with male rabbits once a week after the operation for 1 month. The plugs were then taken out from 10 rabbits (Group 2) 3 months after the operation.ResultsOut of 30 cases (Group 1), only one rabbit from Group 1 was pregnant 2 months after the insertion of the plugs due to improper insertion. However, five rabbits in the control group were all pregnant. All 10 rabbits from Group 2 were pregnant 1 month after the plug was removed.ConclusionThe oviduct plug with Ni-Ti shape memory alloy and silicone rubber is a new, effective and reversible contraceptive tool.