Ovarian Stimulation: How It Works, Hormones Used, and Side Effects
Ovarian stimulation is a crucial step in assisted reproduction treatments, designed to obtain multiple eggs in a single cycle. This process involves administering hormones that stimulate follicular growth, optimizing the chances of success in procedures like in vitro fertilization (IVF). Many women wonder how it works, how the medication is administered, and what side effects it may have. This article explains everything you need to know about this process.
What Is Ovarian Stimulation and Why Is It Necessary?
In a natural cycle, only one follicle matures and releases an egg. However, for IVF and other fertility treatments, multiple eggs are needed to increase pregnancy chances. Ovarian stimulation uses hormonal medication to stimulate the ovaries, allowing multiple follicles to grow simultaneously.
Types of Hormones Used in Ovarian Stimulation
Gonadotropins
Gonadotropins are naturally produced by the pituitary gland and play a key role in ovulation. In ovarian stimulation, they are administered in higher doses to encourage multiple follicular development. The two main types are:
- FSH (Follicle-Stimulating Hormone): Stimulates follicular growth.
- LH (Luteinizing Hormone): Often combined with FSH to mimic the natural cycle and enhance egg maturation.
GnRH Analogues
These are used to prevent premature ovulation, ensuring better cycle control. Two types exist:
- GnRH Agonists: Used in long protocols to suppress the pituitary gland before stimulation begins.
- GnRH Antagonists: Used in short protocols to prevent premature LH surges and reduce the risk of ovarian hyperstimulation syndrome (OHSS).
Recently, progestins have been introduced as an alternative, offering the advantage of oral administration instead of subcutaneous injections.
Trigger Shot for Final Egg Maturation
The final phase of stimulation is known as the “trigger shot,” which promotes final follicular maturation. It involves an injection of:
- hCG (Human Chorionic Gonadotropin): Supports final egg development.
- Low-dose GnRH analogues: Alternative triggers to reduce complications.
- hCG + GnRH combination: Used in specific cases for better ovarian response.
How Is the Medication Administered?
Most ovarian stimulation medications are administered via subcutaneous injections using fine needles. These are self-administered in the abdomen, and although it may seem intimidating at first, most women quickly become comfortable with the process. Medical teams provide detailed guidance and support throughout treatment.
Side Effects of Ovarian Stimulation
Ovarian stimulation is generally well tolerated, but some women may experience mild side effects, such as:
- Abdominal bloating and discomfort: Due to follicular growth.
- Fluid retention: Temporary weight gain or heaviness.
- Mood swings: Emotional sensitivity due to hormonal changes.
- Bruising at the injection site: Common but harmless.
- Changes in vaginal discharge: Increased or decreased lubrication.
- Heavy legs: A feeling of tiredness or swelling.
In rare cases, Ovarian Hyperstimulation Syndrome (OHSS) may develop, causing excessive ovarian enlargement and fluid retention. However, with modern stimulation protocols and close monitoring, this risk has significantly decreased.
Customized Treatment for Maximum Success
Every woman responds differently to ovarian stimulation, which is why treatment must be personalized. Factors such as age, ovarian reserve, BMI, and medical history help determine the most suitable protocol.
Ovarian stimulation is a key step in assisted reproduction treatments, allowing multiple eggs to be retrieved in a single cycle to increase success rates. Thanks to advances in medicine and individualized treatments, the process is now safer and more effective than ever. If you have any concerns about this procedure, our specialists at Clínica Fertia are here to guide you every step of the way.
