IVF stimulation: what to expect from the shots and scans

During IVF stimulation, you give yourself hormone injections and visit the clinic so your team can see how your ovaries respond. Your doses or appointment dates may change along the way. Before you start, make sure you know how to give each medicine and who to call if an instruction is unclear.

The warning signs section near the end lists what needs a call to your clinic and what needs 911.

What is ovarian stimulation?

Most months, your body grows one egg. In IVF, hormone medicines help several eggs grow at the same time. This is called ovarian stimulation, or "stims" for short.

Each egg grows inside a small sac of fluid called a follicle. On ultrasound, your clinic measures the follicles to see how they are growing.

Before your first shot

You will have a full medical exam and fertility tests first. Some people take birth control pills or estrogen before stimulation. These can help stop ovarian cysts and control the timing of your cycle.

Your clinic will give you a medicine plan with start dates. Your doses and timing depend on your test results, so another person's schedule may look different from yours.

If you are worried about giving yourself injections, ask your nurse to walk you through the first dose. It also helps to ask, before day one, who to call with a question after hours.

The medicines, in plain words

Your doctor picks the medicines and doses. Here is what the main types do:

• Gonadotropins. These are the main stimulation shots. They contain hormones like FSH (follicle-stimulating hormone), which helps follicles grow.
• Medicines that stop early ovulation. These are called GnRH agonists or GnRH antagonists. They lower the chance that your body releases the eggs before retrieval.
• Pills. Some plans add clomiphene or letrozole, which are taken by mouth.

Most of these are shots, given either under the skin or into a muscle. The plan for which medicine to use, and when, is called a protocol. Read about the choices in IVF stimulation protocols.

If a dose is late, missed or uncertain, contact your clinic for instructions. Do not guess how to make it up, because the right fix depends on your plan.

How long does IVF stimulation last?

Most stimulations last 8 to 14 days. Your exact number of days depends on how your follicles grow. Your doctor uses your blood tests and ultrasounds to decide when they are ready.

What happens at monitoring visits

Monitoring visits can happen every few days or as often as every day. Each visit has two parts:

• A blood draw. This shows how your hormone levels are rising. Estrogen goes up as the follicles grow.
• A vaginal ultrasound. A thin probe goes into the vagina and uses sound waves to measure each follicle.

Your team uses these results to guide your doses and to time the trigger. Follicle size helps them judge that timing. Still, a scan cannot confirm that each follicle contains a mature egg. Follicles that are too small or too large are less likely to give a mature egg. The eggs are only checked for maturity in the lab, after retrieval.

Before you leave each visit, or when the clinic contacts you after it, make sure you know three things:

• Your next dose: which medicine, how much, and what time
• Your next appointment
• When to expect today's results, and how they will reach you

What can change during stims

Your plan may shift as the clinic sees how your body responds.

A lower response than expected. Stimulation may be stopped if your body has too little response to the medicine. If that happens, your team will talk with you about other ways to manage your treatment.

A higher response than expected. A strong response raises the risk of ovarian hyperstimulation syndrome (OHSS). It does not always mean the cycle ends. Your team may change the plan to reduce that risk. ASRM recommends a GnRH agonist as the first-choice trigger medicine to lower this risk. It also says to consider freezing all embryos for a later transfer in people at risk. Sometimes, though, treatment needs to stop to protect you.

Eggs released early. Rarely, eggs are released before retrieval, even with medicine to stop it. When that happens, the cycle is usually cancelled. If your cycle changes, cancelled cycle or postponed transfer explains what to ask next.

The trigger: getting ready for egg retrieval

When your follicles are ready, your clinic will give you a trigger medicine plan and an exact time to take it. The trigger helps the eggs finish maturing. It may be hCG or another medicine.

Egg retrieval is done 34 to 36 hours after the trigger, and some clinics use exactly 36 hours. Because retrieval is timed from it, the trigger time is the one to protect most. Set more than one alarm. Next comes egg retrieval day.

Common side effects of stimulation

Some people feel side effects. Common ones include:

• Bruising and soreness where you inject (switching sites can help)
• Redness or itching at the shot site
• Bloating, belly discomfort or enlarged ovaries
• Nausea, and now and then some vomiting
• Sore breasts and more vaginal discharge
• Mood swings and tiredness
• Hot flashes or headaches

Mention these at your next visit, or call if one worries you. Some are different: belly pain with bloating, or nausea with vomiting, can be signs of OHSS, so call your clinic right away. All the warning signs are listed below.

Your stimulation checklist

• Medicine plan and start date confirmed
• Medicines picked up and stored the way the label says
• First dose walked through with your nurse
• Shot times set as daily reminders
• Monitoring visits on your calendar
• After each visit: next dose, next appointment and results timing confirmed
• Clinic's after-hours number saved
• Trigger medicine plan and exact time written down, with alarms set
• Retrieval day time and ride home arranged

Before each dose, check the latest instructions from your clinic.

When to get help

OHSS is an excessive response to the stimulation medicines. Fluid leaks into the belly, which can cause bloating and nausea. Mild OHSS is fairly common, but severe OHSS can lead to dehydration and blood clots.

Call your clinic right away, day or night, if you have:

• A fever of 100.4°F (38°C) or higher.
• Bleeding your clinic did not tell you to expect, or a brown, watery discharge.
• Belly or pelvic pain that is sudden or severe, gets worse, or isn't eased by the pain relief your clinic recommended.
• Pain and bloating in your belly, or bloating that is getting worse.
• Nausea and vomiting, nausea that won't go away, or you can't keep fluids down.
• Peeing less than usual, even if you are not thirsty.
• Fast weight gain. Your clinic will tell you its number, but do not wait to reach a weight threshold if you feel unwell.
• Dizziness, lightheadedness, or feeling faint.
• Pain, redness or warmth in an arm or leg.
• Blood in your urine, or pain when you pee or poop.

Tell your clinic at your next contact about other milder symptoms that are new, don't go away or slowly get worse. They can then decide whether you need to be seen.