Intermediate
Technical
IVT
Trigger Shot
An injection of hCG or GnRH agonist given to induce final oocyte maturation before retrieval.
Full Definition
The trigger shot is a precisely timed injection administered to complete oocyte maturation and prepare eggs for retrieval in IVF cycles or ovulation in timed intercourse. Human chorionic gonadotropin (hCG) is the traditional trigger, mimicking the natural LH surge, while GnRH agonists may be used in patients at risk of OHSS. The injection is typically given 34-36 hours before scheduled oocyte retrieval, and timing is critical for optimal egg maturity and retrieval success.
Usage
Usage note: Always specify the type of trigger (hCG vs. GnRH agonist) and exact timing in documentation.
In Context
- "The trigger shot was administered at 10 PM for a scheduled 8 AM ovum pickup." — Nursing protocol
- "GnRH agonist was used as the trigger shot due to the patient's PCOS diagnosis." — Treatment plan
Also known as
ovulation trigger
hCG trigger
final maturation trigger
Don't confuse with
luteal support
ovulation induction