Egg Freezing: What is “Ovarian Stimulation”?

Egg freezing starts with something called "ovarian stimulation" - which may sound technical, but it's actually pretty straightforward.

When you decide to freeze your eggs, your doctor will start you on a medication protocol to stimulate your ovaries. While your body naturally releases one egg per month, for egg freezing to be effective, we want to collect multiple mature eggs in a single cycle. That's what ovarian stimulation is: a process that uses injectable medications to help your ovaries produce several eggs at once, giving you a better chance of preserving good quality eggs for your future.

These medications mimic the natural hormones in your body - just at higher levels - encouraging your ovaries to mature multiple eggs instead of just one. The process typically takes 8-12 days, during which you'll have monitoring appointments to check your progress. Understanding what happens during ovarian stimulation and what you might experience physically can help you prepare for the process ahead. 

In this article, we'll break down the medications used, what to expect at each stage, and how to make the experience more manageable.

What is the purpose of ovarian stimulation?

The main goal of ovarian stimulation is to help you freeze multiple mature eggs at once, improving your chances of having a baby in the future. Think of it like this: when you naturally try to conceive, you're working with one egg per month. If that egg isn't viable or doesn't fertilize, you try again next month. But when you're freezing eggs, you want to maximize your chances by collecting several mature eggs in a single cycle. Getting multiple eggs at once is particularly important because not every frozen egg will successfully thaw, fertilize, or develop into a healthy embryo later. By stimulating your ovaries to mature multiple eggs at once, you increase your options for your future family planning.

What happens in your body during ovarian stimulation

Ovarian stimulation follows a fairly predictable timeline, though each person's experience varies slightly. Here's what you can typically expect during the process:

• Day 1-5: Your ovaries begin responding to the medications, growing multiple follicles simultaneously. Each follicle contains an egg. You'll start regular monitoring appointments to track your progress.
• Day 5-10: Follicles continue growing, and hormone levels rise. Your monitoring appointments become more frequent as your doctor fine-tunes medication doses based on your response.
• Days 10-14: As your eggs reach maturity, your doctor will schedule your trigger shot and egg retrieval. Timing becomes very precise at this stage.

Throughout stimulation, you'll have regular appointments to track your progress:

• Blood tests measure your hormone levels, helping your doctor adjust medication doses for optimal results.
• Ultrasounds show how many follicles are growing and their size. These transvaginal ultrasounds are quick and help your doctor determine when you're ready for egg retrieval.

What you might notice

Physical changes during ovarian stimulation can vary person to person, but commonly include:

• Bloating, especially as follicles grow
• Tenderness in your lower abdomen
• Fatigue
• Breast tenderness
• Mood changes from hormonal fluctuations

Most women maintain their normal activities during stimulation, though you might want to scale back intense exercise as your ovaries enlarge.

Read more in What are the Side Effects and Risks of Egg Freezing?

What to do during ovarian stimulation

Success with ovarian stimulation often comes down to organization and support:

Create a medication schedule:

• Set alarms for injection times
• Keep medications properly stored
• Track your appointments
• Note any symptoms or questions for your doctor

Build your support system:

• Consider having someone help with injections
• Join egg freezing support groups (like Cofertility!)
• Keep your care team informed of any concerns
• Plan for rest when needed

Before beginning stimulation:

• Learn proper injection techniques from your fertility care team
• Organize your medication and supply storage
• Plan your monitoring appointment schedule
• Arrange any needed support
• Clear up any questions about your protocol

As stimulation progresses, your doctor will monitor your follicles' growth and hormone levels to determine the ideal time for egg retrieval. This precise timing helps ensure the highest number of mature, viable eggs for freezing.

Is ovarian stimulation painful?

While ovarian stimulation isn't typically painful, you may experience some discomfort during the process. The daily hormone injections use very thin needles - most women describe them as feeling like a quick pinch. Some report mild soreness at injection sites, similar to how your arm might feel after a flu shot. 

As mentioned above, during stimulation, you might feel increasingly bloated or experience tenderness in your lower abdomen as your ovaries grow larger. This is normal and expected. The monitoring appointments include transvaginal ultrasounds, which might be uncomfortable but shouldn't be painful. If you do experience significant pain during stimulation, it's important to let your doctor know right away

Read more in Does Egg Freezing Hurt?

What is overstimulation?

Ovarian hyperstimulation syndrome (OHSS) is a rare but potential complication where your ovaries respond too strongly to the fertility medications. Think of it as your ovaries becoming overachievers - they produce too many follicles, leading to excessive hormone levels. 

Mild OHSS can cause increased bloating, mild nausea, and abdominal discomfort. More severe cases might involve significant bloating, shortness of breath, or severe abdominal pain. The good news is that OHSS is largely preventable with modern protocols and careful monitoring. Your doctor will track your response to medications through regular blood tests and ultrasounds, adjusting your protocol if needed to minimize this risk. If you're concerned about OHSS, talk with your doctor about your personal risk factors and the precautions they take to prevent it.

The bottom line

Understanding ovarian stimulation is an important step in your egg freezing process! While the daily medications and monitoring appointments might seem overwhelming at first, remember that thousands of women have successfully completed this process before you. Your body is capable of amazing things, and with modern science and proper support, the stimulation phase is usually very manageable.

At Cofertility, we believe knowledge is power. That's why our Member Advocates will be with you every step of the way, ready to answer questions and provide support. Whether you're just starting to research egg freezing or ready to begin your medications, we're here to help you navigate this process with confidence.

Have questions about egg freezing or want to learn more about your options? Reach out to us. We'll help you understand what to expect and how to prepare for this important step in your fertility journey.