What is Zivafert and its Primary Role?
Zivafert is an injectable medication containing highly purified human chorionic gonadotropin (hCG), a hormone that plays a vital role in reproduction. As a pharmaceutical product, it is used to replicate the natural luteinizing hormone (LH) surge that occurs in the body during a normal reproductive cycle. Its primary function in fertility treatments is to act as a "trigger shot," signaling the final stage of egg maturation and release from the ovaries.
The Mechanism of Action
Zivafert's function hinges on its similarity to luteinizing hormone (LH), one of the key hormones in the female reproductive cycle. After a woman's ovaries have been stimulated with other hormones, a dose of Zivafert is administered to mimic the natural LH surge. This artificial surge prompts the final development and release of mature eggs from the ovarian follicles. In males, hCG similarly mimics LH, stimulating the Leydig cells in the testes to produce testosterone and sperm.
Clinical Applications of Zivafert
Zivafert's use is critical in several reproductive health scenarios, primarily under the supervision of a physician experienced in fertility treatment.
In Female Fertility Treatment
- Ovulation Induction: For women who experience irregular or absent ovulation (anovulation or oligo-ovulation), Zivafert is used to trigger the release of eggs from the ovaries. This is typically done after a preceding cycle of follicle-stimulating hormone (FSH) medication has matured the ovarian follicles.
- Assisted Reproductive Technologies (ART): In procedures like in vitro fertilisation (IVF), Zivafert is administered to trigger the final maturation of multiple follicles that have been stimulated by other medications. The timing of this injection is crucial, as it dictates the scheduling of the egg retrieval procedure. The injection is typically given 24 to 48 hours after optimal follicle growth has been achieved.
In Male Fertility and Health
Although often discussed in the context of female fertility, hCG-based medications like Zivafert have off-label uses for men in some countries.
- Fertility Preservation during Testosterone Replacement Therapy (TRT): Men undergoing TRT can experience a suppression of their natural testosterone and sperm production. By mimicking LH, Zivafert helps stimulate the testes to continue producing testosterone and sperm, preserving fertility.
- Hypogonadotropic Hypogonadism: HCG can stimulate androgen production in males with low testosterone levels caused by a pituitary gland condition.
Important Safety Considerations and Side Effects
As with any medication, Zivafert carries potential risks and side effects, and patient monitoring is essential.
Potential Side Effects
Common side effects typically include:
- Headache
- Mood changes or irritability
- Injection site reactions (pain, redness, swelling, bruising)
- Painful breasts
- Swelling (oedema)
Serious Risks to Monitor
- Ovarian Hyperstimulation Syndrome (OHSS): This is the most serious risk for women undergoing fertility treatment. OHSS occurs when the ovaries become overstimulated, leading to swelling, abdominal pain, and fluid accumulation. In severe cases, it can cause rapid weight gain, breathing difficulties, and blood clots.
- Blood Clots (Thromboembolic Events): A rare but serious complication, especially when associated with OHSS. Symptoms like sudden leg pain or shortness of breath require immediate medical attention.
- Multiple Pregnancy: The use of hCG to induce ovulation significantly increases the likelihood of a multiple pregnancy (e.g., twins or triplets), which is considered a higher-risk pregnancy.
- Allergic Reactions: In rare cases, severe allergic reactions, including anaphylaxis, can occur.
Zivafert vs. Recombinant hCG
Zivafert is a urine-derived hCG, while other hCG trigger shots, like Ovitrelle (choriogonadotropin alfa), are produced through recombinant DNA technology.
| Feature | Zivafert (Urine-Derived hCG) | Recombinant hCG (e.g., Ovitrelle) |
|---|---|---|
| Source | Highly purified from the urine of pregnant women. | Produced in a laboratory using genetic engineering. |
| Storage | Does not require refrigeration (ambient storage below 25°C). | Typically requires refrigeration. |
| Preparation | Involves mixing a powder vial with a pre-filled solvent syringe before injection. | Usually comes in a ready-to-use, pre-filled pen for convenience. |
| Efficacy | Demonstrated to be non-inferior to recombinant hCG in clinical trials for number of retrieved oocytes in IVF. | Highly effective for inducing final egg maturation. |
| Potential Risks | Associated with the risk of OHSS and blood clots, similar to other gonadotropins. | Shares similar risks of OHSS and multiple pregnancies. |
Conclusion
Zivafert, a highly purified human chorionic gonadotropin, is a powerful and effective medication used primarily as a trigger shot in fertility treatments. For women, it is instrumental in inducing ovulation for those with ovulatory disorders and preparing eggs for retrieval in IVF cycles. Furthermore, its off-label use provides a valuable option for men undergoing testosterone therapy who wish to maintain their fertility. While effective, its use requires careful medical supervision and monitoring to manage potential side effects, particularly the risk of ovarian hyperstimulation syndrome. The decision to use Zivafert, or a recombinant alternative, should be made in close consultation with a fertility specialist, weighing the benefits against the risks for each individual patient.
For more detailed information on Zivafert, patients can consult the specific product information leaflets provided by the manufacturer, IBSA Fertility.
