HCG Injections During Fertility Treatments

Human chorionic gonadotropin (hCG) is a hormone secreted early in pregnancy by specialized cells called trophoblasts and later by the placenta. HCG injections are sometimes used in fertility treatments to cause an egg to mature and release from the ovary for egg retrieval or intrauterine insemination.

HCG helps maintain high levels of progesterone, which is critical for the success of the pregnancy. It is also the hormone detected by urine and blood pregnancy tests.

This article explains how hCG injections are used in fertility treatments. It also covers how and when to take hCG.

Fertility Treatments With hCG

Because hCG is similar in structure to luteinizing hormone (LH), when there is a mature egg follicle in the ovary an injection of hCG can cause the egg to mature and be released. The medication can be used alone, in an ovulation induction cycle as with intrauterine insemination or during in vitro fertilization.

The hCG injection will cause ovulation approximately 36 hours after you take it, allowing your healthcare provider to better time intrauterine insemination or the egg retrieval.

Many brands and forms of hCG are available. Your healthcare provider will prescribe the one most appropriate for you. Injections can be given either subcutaneously or intramuscularly, depending on the brand.

Preparing or Mixing hCG

HCG injections come in several forms. Some come pre-mixed, while others require mixing.

Ovidrel

One form of hCG, Ovidrel, comes in a 250 microgram (mcg) prefilled syringe. Once you open the box, the medicine is already prepared and loaded in the syringe with the needle attached.

Simply open the packaging, remove the air bubble by holding the syringe with the needle facing up, and slightly depress the plunger until all the air is removed, and inject the medication subcutaneously.

Pregnyl or Novarel

Pregnyl or Novarel (hCG, human chorionic gonadotropin) also comes in a box with a 5,000 10,000 or 20,000 unit vial of powder and a vial of diluent (liquid) which is used to mix the powder. Your healthcare provider will tell you how many units of the medicine to take and how they prefer you to mix it.

For example, if you are taking 10,000 units, you will remove 2 milliliters (mL) of diluent and inject it into the powder. Allow the powder to dissolve and then pull the entire 2 mL back into the syringe. Inject the medication intramuscularly or subcutaneously, according to your healthcare provider’s instructions.

When to Take hCG

This medication is taken once there is a mature egg follicle in the ovary. Your healthcare provider will most likely give you a specific time or time frame to take the hCG injections. It is important to tell your healthcare provider if you do not take the medication on time in case any adjustments need to be made.

If you will be having intercourse or intrauterine insemination, ovulation will occur approximately 36 hours after you inject hCG, so the day of the injection and two days following it are your critical days. If you will be having egg retrieval as in an IVF cycle, it will occur close to that 36-hour mark so as to optimize the maturation but avoid ovulation.