Trigger Shot

A trigger shot is an injection of hormones that tells the ovaries to mature and release eggs. It works by kickstarting the process of egg maturation that is required for an egg to be capable of fertilization. Maturation involves a division (called meiosis) where an egg typically sheds 23 (or half) of its 46 chromosomes.

A trigger shot is used to time intrauterine insemination (IUI) or to prepare for an egg retrieval procedure as part of in vitro fertilization (IVF).

A trigger shot may also be called an hCG trigger shot or by the brand names Ovidrel, Pregnyl or Novarel.