Embryo transfer catheters are commercially available . Each catheter is very flexible and has a rigid outer sleeve. The catheter has an internal diameter of 1mm and has either a ‘side-hole', approximately 1 mm below the tip or an ‘end-hole'. The distal end of the catheter is marked at 1 cm intervals.

The ‘end hole' catheter is more convenient to load while the ‘side hole' prevents the blockage of the catheter tip with mucus while the catheter is inserted into the uterus.

Loading of Catheter :

The transfer catheter is connected to a 1 ml tuberculin syringe and flushed with growth medium. The catheter is held horizontally and all the embryos are loaded at the tip within a 15 -20 microliters of medium with air bubble on either side to prevent capillary action so that embryos don't fall unexpectedly. The catheter is loaded only after the patient lies in the appropriate position.

Embryo Transfer :

The loaded catheter covered by its outer sheath is brought quickly from the culture laboratory and guided into the uterine cavity. The catheter is then gently inserted into the uterus in such a way that the tip is 1 cm below the uterine fundus. The embryos are then expelled into the uterus by pushing the plunger of the syringe. The catheter is left undisturbed for 15-30  seconds and then gently withdrawn.

The catheter is flushed in the transfer medium under the microscope to ensure that no embryos have been retained . After the transfer, the patient's legs are straightened out and she is asked to rest for 4 hrs after which she is discharged.

Frozen Embryo Transfer :

Embryos freezing allows multiple embryo transfers from a single egg collection and improves the chances of live birth. Frozen/thawed embryos may be transferred into the uterus in a natural cycle, a hormone replacement cycle or a stimulated cycle.