Definition - What does Trigger Shot mean?
A trigger shot is an injection of synthetic human chorionic gonadotropin (hCG), which is a hormone medication used to stimulate the maturation of follicles (immature eggs) and trigger ovulation.
A trigger shot may also be called an hCG trigger shot or by the brand names Ovidrel, Pregnyl or Novarel.
FertilitySmarts explains Trigger Shot
When dealing with irregular ovulation or in preparation for egg retrieval procedure, medication (like chlomid) is taken to stimulate the production of egg follicles. The development of follicles is followed by ultrasound to determine when they have reached the optimal number and size. When the appropriate time arrives, a trigger is adminstered to cause the dominant follicle(s) to release its egg, generally resulting in ovulation about 36-46 hours after the shot.
Because home pregnancy tests measure natural levels of hCG in your urine, it is advisable to wait at least 10 days after you receive the trigger shot to allow the synthetic hCG hormone to dissipate from your system.