We use a trigger shot in IVF and IUI procedures to prompt ovulation at a specific time
A trigger shot, also known as an ovulation trigger, is an injectable medication that induces final egg maturation and ovulation. We use trigger shots in fertility treatments like in vitro fertilization (IVF) or intrauterine insemination (IUI). A trigger shot accurately times a woman’s ovulation to coincide with the treatment plan of her cycle.
During a woman’s monthly cycle, eggs grow mature in the ovaries. In a natural hormone cycle, the hypothalamus, which controls the release of various hormones during the month, signals the pituitary gland to release luteinizing hormone (LH). This surge of LH triggers ovulation about 36 hours later.
What specifically is the trigger shot?
In a medicated cycle, we mimic the natural LH surge with a trigger shot before your timed intercourse, IUI, or egg retrieval in IVF. A trigger shot prompts the final maturation of eggs in the ovaries and induces ovulation for the purposes of scheduling your procedure. Without this precise timing, it would be impossible to have all the pieces of your treatment puzzle together at the right time when your body decides to ovulate. Additionally, a trigger shot may be necessary for some women who have trouble ovulating to begin with, such as those with polycystic ovary syndrome and insulin resistance.
The shot consists of hCG, or human chorionic gonadotropin, a hormone that ensures the eggs are ready for retrieval or fertilization at the optimal time. Common pharmaceutical names of hCG include Ovidrel, Novarel, and Pregnyl. Your treatment plan specifies the specific drug you will use. While hCG is the most common medication, we sometimes use Lupron (an GnRH agonist) as well, especially in cases of increased risk of ovarian hyperstimulation syndrome (OHSS).
When is the right time to take a trigger shot?
It’s crucial to administer the trigger shot at the correct time, as determined by your Fertility Answers team. Administer your trigger shot 24-36 hours before your IVF egg retrieval or IUI procedure according to your cycle plan. This ensures eggs are ready for retrieval or fertilization at the right time. The timing is crucial to ensure eggs are ready for fertilization. You will typically self-administer your trigger shot, either intramuscularly or subcutaneously, based on the specific medication prescribed.
It’s important to note that hCG can remain in your body for several days. HCG is often called the pregnancy hormone as it is made naturally by cells formed in the placenta. The placenta nourishes the egg after it has been fertilized and becomes attached to the uterine wall. Because of this, beware of taking a pregnancy test too early. It can potentially cause a false positive pregnancy test!
Make sure you understand your cycle plan correctly so that you take your trigger shot at the right time. Ask questions of your care team if you are unsure.
