Why is hCG trigger injection used in ovarian stimulation?

Medicines used for ovarian stimulation encourage several follicles to grow. When monitoring shows that the follicles are ready, hCG can act in a similar way to the natural luteinising hormone signal. This starts the final stage of egg maturation and allows the fertility team to plan egg collection or intercourse or insemination around a predictable window.

The injection does not replace the earlier stimulation medicines. Its timing matters, so taking it at the instructed time is part of the treatment plan. An hCG trigger may also affect pregnancy-test results for a short period because tests detect hCG.

Follow the clinic's instructions for storage, preparation, injection technique, and exact timing. Keep the appointment for ultrasound or blood-test monitoring, and tell the team if the dose is late, missed, spilled, or given incorrectly. Ask which pain relief is suitable and when to test for pregnancy, since an early test can be misleading.

Contact your fertility clinic promptly for severe or increasing abdominal swelling or pain, repeated vomiting, difficulty breathing, faintness, or a marked reduction in urination. These symptoms can signal ovarian hyperstimulation or another problem needing assessment. Seek urgent help for collapse, severe breathing difficulty, or sudden severe pain.

Ask what the trigger is expected to achieve, the exact injection time, what happens if the timing is missed, and when egg collection, insemination, intercourse, or pregnancy testing should occur.