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Fertility Glossary

hCG trigger

Using hCG to mature the eggs before collection.

Medicines & protocols

An hCG trigger mimics the natural LH surge to complete egg maturation, and is the traditional trigger in both IVF and IUI cycles. Because hCG stays in the body for several days, it supports the corpus luteum but also raises OHSS risk in high responders, and it can cause a false positive on a home pregnancy test taken too soon after the injection.

Also known as: HCG injection, Ovitrelle trigger, choriogonadotropin

Related South Africa guides

Sources

  • SAHPRA (South African Health Products Regulatory Authority)
  • ESHRE guidelines and patient information

Last reviewed: 8 September 2026. Written by the Antega Editorial Team. General information only — always follow the advice of your own clinic, doctor or pharmacist.

Related terms

Trigger injection

The final injection that matures the eggs before collection.

Agonist trigger

Using a GnRH agonist instead of hCG for final egg maturation.

hCG (human chorionic gonadotropin)

The pregnancy hormone; also used as a trigger injection in fertility treatment.

Ovarian hyperstimulation syndrome (OHSS)

An over-response to fertility medication causing swollen, painful ovaries.

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