Transcervical insemination (TCI) is a sophisticated assisted reproductive technique used to help achieve pregnancy. This method involves carefully placing semen directly into the uterus, bypassing the cervix. It is a less invasive alternative to surgical insemination, aiming to optimize the chances of successful fertilization.
What is Transcervical Insemination
Transcervical insemination (TCI) delivers sperm directly into the uterus, bypassing the cervix. This direct placement helps ensure semen reaches the optimal location for fertilization, reducing the distance sperm must travel. TCI differs from intracervical insemination (ICI), where sperm is placed in the cervix, and intrauterine insemination (IUI), which also places sperm directly into the uterus but typically involves washed sperm and is performed in a clinic. TCI is performed without anesthesia, making it a less stressful option than surgical insemination. This technique is particularly advantageous when using frozen or chilled semen.
How the Procedure is Performed
The transcervical insemination procedure begins with preparation, such as ovulation timing to identify the female’s fertile window, involving serial blood progesterone tests and vaginal cytology. During the procedure, the female stands awake, sometimes with a light sedative. An endoscope with a camera is gently inserted into the vagina to visualize the cervix. A thin catheter is then guided through the endoscope and advanced through the cervix into the uterus.
Once positioned, the prepared semen (fresh, chilled, or frozen) is slowly deposited directly into the uterus using a syringe. This direct uterine placement maximizes the number of sperm reaching the oviducts by reducing loss due to backflow. The procedure takes 15 to 30 minutes and is minimally painful, with most females tolerating it well. Some facilities assess semen quality immediately before insemination to ensure viability.
Reasons for Choosing Transcervical Insemination
Transcervical insemination is chosen when natural mating is impractical or challenging. It is useful for breeding geographically distant animals, allowing for the use of shipped chilled or frozen semen. This method broadens the genetic pool, enabling breeders to access a wider variety of bloodlines.
TCI is also considered when natural breeding is difficult due to size discrepancies, temperament issues, or physical limitations. For semen with reduced viability, such as frozen-thawed or suboptimal chilled semen, TCI is preferred as it increases fertilization chances. TCI also reduces physical stress and potential for injury during natural mating, and minimizes the risk of transmitting sexually transmitted diseases.
Expected Outcomes and Success Rates
Following transcervical insemination, the timeline for determining pregnancy typically involves an ultrasound examination around four weeks post-breeding. The success rates for TCI can vary, with studies indicating pregnancy rates around 83.21% for fresh semen, 67.16% for chilled semen, and 66.67% for frozen-thawed semen. Litter sizes also show variation, averaging around 6.82 puppies per litter with fresh semen, 5.21 with chilled, and 4.59 with frozen-thawed.
Several factors influence these outcomes, including the quality and type of semen used, the precise timing of the insemination within the female’s fertile window, and the overall reproductive health of the female. Performing two TCIs during the fertile period, rather than one, can increase the pregnancy rate by approximately 6.6% and litter size by about 0.7 puppies per litter. While TCI generally offers higher success compared to vaginal artificial insemination, it is important to note that even with optimal timing and semen quality, pregnancy is not always guaranteed.