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1168 Transcervical Insemination

Transcervical Insemination
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oocytes are present only after day 4-5, and
Difficulty Level: ♦♦
by day 8, the oocytes become senescent. used to follow the semen into the uterus and
flush the catheter.
Overview and Goals Before day 4, the cervix will be difficult to • If using cooled shipped semen or semen
• Transcervical insemination (TCI) involves the catheterize. extended to a volume greater than 5 mL,
endoscopic visualization of the cervix and • The LH surge can be timed directly by the semen should be centrifuged at 900 g
its catheterization. Semen is then injected testing LH or indirectly by monitoring serum for 1 2 min/mL. The supernatant should be
through the catheter and into the uterine progesterone and looking for the rise above drawn off until the ideal volume is achieved,
lumen. 1.5-3 ng/mL. and the remaining pellet is resuspended.
• The two primary methods of intrauterine • When timing insemination, it is important • Frozen semen should not be thawed until
insemination are catheterization of the cervix to consider the longevity of the semen based the cervix is successfully catheterized.
by TCI or injection of semen into the uterine on its handling and state (fresh vs. cooled Thaw instructions and procedures should
lumen by laparotomy. shipped vs. frozen). be followed. It is recommended to prepare
• TCI requires specific equipment and careful • Typical breeding management with any type for thawing in advance to ensure that
breeding management. of semen includes two inseminations between insemination occurs within a few minutes
days 4 and 7: of catheterization of the cervix.
Indications ○ The frequency of insemination using TCI
• Intrauterine insemination is required when is limited only by the ability to catheterize Possible Complications and
using frozen-thawed semen. the cervix. Once-daily inseminations, Common Errors to Avoid
• Female subfertility although not usually necessary, are possible • Occasionally, it is not possible to catheter-
• Cases in which the semen is reduced in during days 4-7 or as long as the cervix ize the cervix. This is affected by factors
viability or dosage (<150 million progres- can be catheterized. such as the stage of the estrous cycle, size
sively motile, morphologically normal Semen preparation and evaluation: of the female, and parity. It may also be
sperm) • The minimal intrauterine dose of semen is necessary to use a catheter with a narrower
• TCI can be used for ruling out vaginal or 75 million morphologically normal, progres- diameter.
cervical abnormalities through visualization sively motile sperm. Optimal pregnancy rates • The anatomy is challenging because the
of these areas and catheterization of the are obtained with doses > 100 million mor- natural angle of the cervical canal is cranio-
cervix. phologically normal, progressively normal dorsal. Adjusting the angle of the endoscope
sperm. can straighten the vagina and cervix.
Contraindications • The volume of semen injected into the • Inadequate insufflation can result in poor
If the bitch is not in late estrus, the vaginal uterine lumen should be between 1 mL visualization of the external cervical os.
wall is more sensitive, and the procedure is and 3 mL. The size of the bitch and the • Excessive serosanguineous discharge, espe-
uncomfortable and more likely to require capacity of the uterus will determine the cially in early estrus, can hinder visualization.
sedation. ideal insemination volume. If needed, this discharge may be aspirated
• If using freshly collected semen, every effort through the scope or by urinary catheter.
Equipment, Anesthesia should be made to fractionate the collection
• Endoscope to separate the sperm-rich portion. The Procedure
○ Extended-length, rigid cystourethroscope volume of the sperm-rich fraction is usually • Equipment and semen should be prepared in
with a working length of 29 cm and less than 3-5 mL. If TCI is scheduled to advance to limit the time the dog is restrained.
22 Fr diameter; ideal for dogs 25-75 lb occur within a short time, the unextended • The dog is restrained in a standing position
(12-35 kg). It should have a 30° viewing sperm-rich fraction can be used. If additional on a table. Restraint should include a person
angle with a sheath and a bridge. Use volume is needed, the prostatic fluid can be or device to limit forward movement and
with urinary catheters 6-8 Fr in diameter.
○ Cold light source and cable
• Camera and video tower system
• Adjustable-height exam table with nonslip
surface
• Anesthesia or sedation is not usually required;
a bitch in estrus tolerates the procedure very
well. Smaller breeds are more likely to require
sedation.
Anticipated Time
10-40 minutes
Preparation: Important
Checkpoints
Breeding management and insemination
timing:
• The ideal timing for TCI is days 5-7 after
the luteinizing hormone (LH) surge (LH TRANSCERVICAL INSEMINATION Morphologic/anatomic specimen shows the external cervical opening
surge = day 0). This is based on oocyte in a bitch, located at the cranial ventral portion of the dorsal vaginal fold. A metal probe has been passed
viability and the degree of cervical relaxation through the cervical canal, illustrating the special challenge faced during transcervical insemination. (Copyright
required for catheterization. Secondary Dr. Robert Lofstedt.)

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