Towako is the transfer of the embryo (fertilized egg) into the endometrial cavity under ultrasound guidance using a needle that is passed through the muscle of the uterus up to the edge of the endometrial lining.
Towako is appropriate for women who have a very tight cervix that does not allow dilation or will not allow the passage of the small catheter used during embryo transfer. It is also appropriate for women who have had partial removal or resection of the cervix because of a history of cervical cancer.
To prepare for Towako, a woman goes through the regular ovulation induction with hormones, egg retrieval, IVF and embryo development in the lab. On the day of the embryo transfer, she will require IV sedation (anesthesia).
The vagina will be prepared for the transfer and a trans-vaginal ultrasound will be carried out to identify the endometrial lining and the suitable place for the embryo transfer.
Two needles (one inside of the other) will then be passed through the vagina into the wall of the uterus and advanced up to the edge of the endometrial lining. The inner needle is removed and replaced by the tiny catheter loaded with the embryos to be transferred. Once the tip of the catheter reaches the tip of the needle, it is advanced one millimeter into the lining of the uterus. The embryos are then released and the catheter and needle are removed together.