Abstract

PIP: Details of the transfer of conceptuses into the uterus after fertilization of oocytes in vitro are supplied. Transfer has usually been carried out at the 3- to 6-cell stage about 44 hours after insemination. When the transfer of more than 1 conceptus is done, the 2nd and 3rd conceptuses may be in a much earlier stage of development. The transfer catheter, of American Wire Gauge number 20 Teflon tubing, has an internal diameter of .8636 mm and an outside diameter of 1.4732 mm. A side notch is cut in the tubing so that a stream of liquid forced from the catheter will eject at a 45 degree angle. Each catheter measures about 30 cm in length. Culture medium and conceptus are drawn into the catheter by a 1 ml tuberculin syringe with a number 18 needle. The catheter is inserted through a carrying tube with a slightly curved tip made from number 12 steel needle tubing with a 2.157 mm internal diameter. The catheter is flushed for about 25 cm once or twice prior to loading the conceptus. The conceptus is transferred to a 60 mm tissue culture dish for convenience in loading and to have a flat surface for photography. The conceptus is drawn into the catheter under the microscope in such a way that it lies about 11 cm from the side opening near the catheter tip, with the entire column of medium including 2 air gaps occupying 22 cm of catheter length. Transfer is carried out in the knee-to-chest position so that patients' uteri are in the normal anterior position. Patients receive 250 mg of tetracycline 4 times daily on the day before and the day of transfer. The tip of the metal catheter is inserted barely into the mucus at the external os, and the transfer catheter is passed through the cervix for a predetermined distance. The entire column of medium is quickly ejected, followed by air to clear the catheter. A moment or 2 later the catheter is withdrawn and examined for presence of conceptus. The patient remains prone in the recovery room for a minimum of 4 hours. The procedure was used 94 times from January 1, 1981-June 30, 1982, resulting in 21 pregnancies. Difficulty was encountered only once in passing the catheter into the uterine cavity, and a conceptus was found remaining in the catheter only once after a transfer.