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Gonadotrophin (Ovulation Trigger) Pregnancy: Used in ART cycles — not for use in established pregnancy

Human Chorionic Gonadotrophin (hCG)

Brand names: Ovitrelle (choriogonadotropin alfa), Pregnyl (urinary hCG)

Adult dose

Dose: Ovitrelle: 250 mcg SC single dose (recombinant). Pregnyl: 5000–10,000 units IM single dose.
Route: SC (Ovitrelle) or IM (Pregnyl)
Frequency: Single dose (ovulation trigger, 36h before oocyte retrieval/planned intercourse)
Max: 250 mcg SC (Ovitrelle) or 10,000 units IM
Trigger shot for IVF oocyte retrieval (given 34–36h before) or ovulation induction (timing intercourse). In high OHSS risk: consider GnRH agonist trigger (if on antagonist protocol) instead of hCG.

Paediatric dose

Route: N/A
Frequency: N/A
Max: Not applicable
Not applicable in paediatric patients

Dose adjustments

Renal

No dose adjustment required

Hepatic

No dose adjustment required

Clinical pearls

  • hCG trigger causes OHSS — in high-risk women, GnRH agonist trigger (instead of hCG, on antagonist protocol) dramatically reduces OHSS risk
  • Timing precision essential: oocyte retrieval performed exactly 34–36h after hCG administration
  • Home pregnancy test: hCG trigger will cause positive urine pregnancy test for up to 14 days after injection — do not test before 14 days post-trigger
  • Recombinant (Ovitrelle) preferred over urinary (Pregnyl) in many centres: more consistent bioavailability

Contraindications

  • Active OHSS
  • Ovarian cyst
  • Undisclosed sex hormone-dependent neoplasm

Side effects

  • OHSS (main risk — can be severe with hCG trigger)
  • Injection site reaction
  • Headache
  • Fatigue

Interactions

  • GnRH agonist/antagonist protocols — interact in complex IVF stimulation protocols (as per clinic protocol)

Monitoring

  • Transvaginal USS (follicle development before trigger)
  • Signs of OHSS after administration
  • Serum oestradiol (pre-trigger to confirm readiness)

Reference: BNFc; BNF; ESHRE ART Guidelines; NICE CG156. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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