The road to making a baby can certainly be a bumpy one with many twists and turns.

A Pew research study uncovered that 33 percent of Americans have used fertility treatments themselves or know someone else who has. And according to the American Society for Reproductive Medicine, less than 3 percent of couples undergoing fertility treatments wind up using advanced reproductive technologies — like in vitro fertilization (IVF) — to conceive.

The IVF process involves stimulating egg production to later retrieve the eggs and fertilize them in a lab. After that, the embryos are transferred back into the uterus with the hope of implantation. IVF uses different medications/hormones timed at different points throughout the cycle.

Some women may develop complications like ovarian hyperstimulation syndrome (OHSS) in response to all the extra hormones they’re taking. OHSS happens when the ovaries swell with fluid that eventually leaks into the body. This condition is a direct result of the drugs used in IVF and other procedures that enhance egg production and maturity.

OHSS is considered an “iatrogenic” complication. This is just a fancy way of saying that it results from hormone therapy used in certain fertility treatments. Mild OHSS happens in up to a third of all IVF cycles while more moderate to severe OHSS happens only 3 percent to 8 percent of the time.

Specifically, a woman undergoing IVF typically receives an hCG (human chorionic gonadotropin) trigger shot before retrieval to help her eggs mature and to put them into an important process called meiosis (when the egg releases half of its chromosomes before ovulation). While this medication helps prime the eggs, it may cause the ovaries to swell and leak fluid into the abdomen, sometimes significantly.

You may notice that we’re using eggs (plural) here. In a natural cycle, a woman typically releases one mature egg during ovulation. During IVF, the goal is to mature many eggs to maximize chances of success. Fertility treatments literally stimulate the ovaries to do this. But it’s when there’s hyperstimulation that it becomes a problem — hence OHSS.

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Less commonly, OHSS can arise after taking injectable hormones or even oral medications like Clomid as part of intrauterine insemination (IUI). Again, these drugs are used to promote egg production or release mature eggs.

And there are some very rare cases where OHSS can happen without fertility treatments.

Risk factors

Risk factors include things like having polycystic ovary syndrome (PCOS) or having a large number of follicles in any given cycle. Women younger than age 35 are also at a higher risk of developing this complication.

Other risk factors:

  • previous episode of OHSS
  • fresh versus frozen IVF cycle
  • high estrogen level during an IVF cycle
  • high doses of hCG during any given IVF cycle
  • low body mass index (BMI)

Related: 5 things to do and 3 things to avoid after your embryo transfer

There’s a lot going on with your body during IVF. It may be hard to tell when something is wrong versus just uncomfortable. Trust your instincts, but also try not to worry. Most cases of OHSS are mild.

Symptoms include things like:

  • abdominal pain (mild to moderate)
  • bloating
  • gastrointestinal issues (nausea, vomiting, diarrhea)
  • discomfort around your ovaries
  • an increase in your waist measurement

These symptoms typically develop about 1 to 2 weeks after injecting medications. The timeline is individual, however, and some women may start symptoms later on down the line.

Symptoms tend to range in their severity and may also change over time. Around 1 percent of women develop what is considered severe OHSS.

Symptoms include:

  • notable weight gain (2 or more pounds in a single day or 10 pounds in 3 to 5 days)
  • more severe abdominal pain
  • more severe nausea, vomiting, and diarrhea
  • development of blood clots
  • decreased urine output
  • difficulty breathing
  • abdominal swelling or tightness

It’s important to get immediate treatment if you experience severe symptoms and have any risk factors of OHSS. Issues like blood clots, trouble breathing, and severe pain may lead to more serious complications, like an ovarian cyst rupture with excessive bleeding.

Mild OHSS may go away on its own within a week or so. If you get pregnant that cycle, the symptoms may persist a bit longer — more like a few days to a few weeks.

Treatment of mild OHSS is conservative and involves things like avoiding strenuous exercise and increasing fluid intake to address dehydration. You may want to take some acetaminophen for pain.

Most importantly, your doctor may ask you to weigh and otherwise monitor yourself daily to track any potential worsening of the condition.

Severe OHSS, on the other hand, often requires a hospital stay — and can be very dangerous (even fatal) if left untreated. Your doctor may decide to admit you to the hospital if:

  • your pain level is considerable
  • you’re having trouble staying hydrated (due to gastro issues)
  • your OHSS seems to be getting worse even with intervention

At the hospital, you may be given intravenous (IV) fluids to aid with hydration. In some cases, your doctor may want to alter your dose of fertility medication. You may be placed on a blood thinner to prevent blood clots.

Your doctor may also recommend paracentesis, which is a procedure that can remove excess fluid buildup in your abdomen. And there are certain medications you can take to calm down all that activity going on in your ovaries.

While frustrating, your doctor may additionally recommend delaying your scheduled embryo transfer — essentially skipping your current treatment cycle. The good news is that you can freeze your embryos for transfer when you are symptom-free.

Related: The 30-day guide to IVF success

There are a variety of ways you can work with your doctor to lower your odds of developing OHSS.

Your doctor may:

  • Adjust your dose of medication. Lower doses may still help stimulate egg production and maturation/release while not overstimulating your ovaries.
  • Add medications to your protocol. There are certain drugs, like low-dose aspirin or dopamine agonists, that may guard against OHSS. Calcium infusions are another option. Women with PCOS may also benefit from adding metformin to their medications lists.
  • Suggest to you “coast.” This basically means that if your doctor sees that your estrogen levels are on the high end or if you have many developed follicles, your doctor may choose to discontinue the use of injectables. Your doctor may wait a few days after that to then give the trigger shot.
  • Eliminate the trigger shot altogether. In some cases, your doctor may even try different methods to help you release eggs. Leuprolide is an alternative to hCG and may prevent you from developing OHSS.
  • Freeze your embryos. Again, your doctor may also suggest that you freeze your follicles (both the mature and immature) so you can transfer the fertilized embryos in a future cycle. This involves retrieval of the eggs and then undergoing a frozen embryo transfer (FET) after letting your body rest.

Every case is unique, and your doctor will likely monitor you closely to decide how to proceed. Monitoring usually involves a mix of blood tests (to check hormones) and ultrasounds (to check on all those developing follicles).

Related: Is ovarian tissue freezing better than egg freezing?

The majority of OHSS cases are mild versus severe. If you feel you’re at risk, share your thoughts and concerns with your healthcare provider. There are a number of things you can do to try and prevent this complication, and your doctor can provide guidance on what’s right for you and your body.

If you do develop OHSS, keep a close eye on your symptoms. Mild cases can resolve on their own with rest and time. Severe cases may land you in the hospital for care. So, if at any point something feels off or wrong, don’t hesitate to contact your doctor ASAP.