OHSS Symptoms After Egg Retrieval: When to Call

You are a few days past egg retrieval. Your abdomen feels enormous, you have gained four pounds, and the discharge sheet said "watch for OHSS." You are reading because you are not sure whether what you feel is the usual post-retrieval bloating or the start of something that needs the emergency room tonight. This post covers OHSS symptoms after egg retrieval, what is normal versus not, and when to call. I will be honest about when to wait, when to call, and when to drive.

When to call your clinic right now

I am putting the safety information first, before the physiology, because some readers are symptomatic at the moment they open this page.

Go to the emergency room if you have any of the following:

• Shortness of breath, or chest pain.
• Severe abdominal pain not relieved by acetaminophen.
• Sudden weight gain of more than three kilograms in twenty-four hours.
• Persistent vomiting that prevents you from drinking.
• Fainting.
• Calf pain or swelling.

Call your clinic the same day if you have weight gain of one to two kilograms in twenty-four hours, increasing abdominal distension, reduced urine output, or persistent nausea.

The rest of this post explains why these things matter, who is at risk, and how doctors prevent the syndrome from getting that far. If you are symptomatic, call first and read second.

What OHSS actually is

Ovarian hyperstimulation syndrome (OHSS) is the body's exaggerated response to the hormonal signals that triggered final egg maturation. The trigger shot, usually human chorionic gonadotropin (hCG), drives the ovaries to keep producing vasoactive substances, particularly vascular endothelial growth factor (VEGF), well beyond the moment of retrieval. These substances increase vascular permeability, which means fluid leaks out of blood vessels into spaces it does not belong: the peritoneum (causing abdominal swelling), and in severe cases the pleural cavity (causing breathing difficulty).¹

The syndrome is classified into mild, moderate, severe, and critical categories by published criteria from the American Society for Reproductive Medicine (ASRM) and the Royal College of Obstetricians and Gynaecologists (RCOG).¹,⁵ The classification matters because management is different at each level.

There are also two timing patterns to know. Early OHSS appears within the first nine days of the trigger shot and is driven by the exogenous hCG you were given for trigger. Late OHSS appears later, between days ten and seventeen, and is driven by the hCG produced by an implanting embryo if pregnancy occurs. Late OHSS is one of the major reasons many clinics now freeze all embryos and transfer in a later cycle: no pregnancy hCG in the stim cycle means no late OHSS.⁴

The good news: severe OHSS has become uncommon in well-managed cycles since the antagonist protocol and agonist trigger became standard. OHSS is rare now in well-managed cycles. But if your gut says something is wrong, call. We would rather be paged at midnight than see you in the emergency department.

Who is at risk

Not every IVF patient is at meaningful OHSS risk. The risk concentrates in patients with the following features.¹,⁶

• High anti-Müllerian hormone (AMH), particularly above three and a half nanograms per millilitre. Levels above five place you firmly in the high-risk group.
• High antral follicle count (AFC), typically above twenty-four follicles total between the two ovaries on baseline scan.
• Polycystic ovary syndrome (PCOS): This is the single strongest risk factor, which is why IVF with PCOS is planned around prevention.
• Younger age, particularly under thirty-five.
• Lower body mass index (BMI): OHSS is more common in thinner patients.
• High estradiol on trigger day, particularly above three thousand five hundred to four thousand picograms per millilitre.
• High follicle count at trigger, particularly more than fifteen to twenty follicles measuring over eleven millimetres.
• Prior OHSS in any cycle, even mild.

If two or more of these apply to you, OHSS prevention should be discussed at your stim planning visit, not improvised mid-cycle.

OHSS symptoms after egg retrieval: the escalation ladder

OHSS rarely arrives all at once. It usually climbs through a recognisable sequence, and being able to name where you are on the ladder helps both you and your clinic make the right call.

Mild OHSS is expected after a strong response. Symptoms include bloating, mild abdominal discomfort, weight gain under two kilograms, and a sense of fullness. Manage at home with rest, electrolytes, and clinic check-ins.

Moderate OHSS is a call-the-clinic-the-same-day scenario. Symptoms include persistent nausea, vomiting, weight gain of two to three kilograms in a few days, visible abdominal distension, reduced urine output, and increasing pelvic pain.

Severe OHSS is an urgent assessment, often in hospital. Symptoms include shortness of breath at rest or with mild exertion, severe abdominal pain, weight gain over three kilograms in twenty-four hours, severe vomiting and dehydration, dizziness on standing, significantly decreased urine output, and calf pain or swelling. The deep vein thrombosis (DVT) risk is real in this state because oestrogen levels are high and dehydration concentrates the blood.

Critical OHSS is a hospital admission scenario. The hallmarks are tense ascites filling the abdomen, pleural effusion compressing the lung, oliguria or anuria, and risk of thromboembolism. This is rare, but every IVF reader should know the picture exists.

What is normal after egg retrieval and what is not

Some bloating and discomfort after egg retrieval is universal. The question every reader asks is which of those symptoms is OHSS and which is just recovery. The honest answer is that early on they overlap, and you have to watch the trajectory rather than any single number.

Normal post-retrieval: two to four days of bloating, a sense of pelvic pressure, light spotting, mild constipation, soreness at the vaginal puncture sites, and ovaries that feel large because they are.¹ The egg retrieval recovery guide walks through the ordinary version. Recovery is gradual and the symptoms get better each day. Weight may go up a kilogram from fluid retention and stay there for a few days before falling.

Not normal: rapid weight gain over twenty-four hours, severe shortness of breath, pain that is not relieved by paracetamol, vomiting that prevents you from drinking, urine output that has dropped noticeably below your usual, or calf pain. These are not part of normal recovery and need a clinic call, not a wait-and-see.

The trajectory matters. Symptoms that are slowly improving day to day are usually fine. Symptoms that are getting worse, or that have stayed the same when they should be improving, are the ones that warrant a call.

How to prevent OHSS after egg retrieval, the four big levers

Modern IVF practice has largely shifted from treating OHSS to preventing it. There are four prevention strategies that, used together, have made severe OHSS uncommon.⁴,⁶

Trigger choice

The single most powerful lever. In antagonist protocols, the trigger can be a GnRH agonist (Lupron) instead of hCG. Agonist trigger produces a short, physiological LH surge from your own pituitary and clears within hours, instead of the days-long hCG signal. Severe OHSS rates after agonist trigger in high-risk patients are near zero.³ Dual trigger combines a low dose of hCG with the agonist, capturing some of the maturation benefit of hCG while keeping OHSS risk low. The trade-off of agonist-only trigger is a weak luteal phase, which is why many clinics combine it with freeze-all.

Freeze-all strategy

If there is no fresh transfer, there is no pregnancy hCG, and therefore no late OHSS.⁴ In any high-risk patient, the freeze-all strategy is now standard of care. All viable embryos are vitrified at the blastocyst stage and transferred in a separate frozen embryo transfer (FET) cycle four to eight weeks later, after the ovaries have shrunk to baseline and oestrogen has fallen.

Dopamine agonist (cabergoline)

Cabergoline, given at low dose starting on trigger day and continued for around eight days, reduces vascular permeability through a mechanism that interrupts the VEGF cascade. The Cochrane evidence supports a reduction in moderate and severe OHSS in high-risk patients.² It is not a substitute for the other preventions, but it adds a meaningful margin of safety on top of them.

Dose individualisation

The fourth lever is the simplest and the most ignored. Starting gonadotropin dose should be matched to AMH, AFC, age, BMI, and prior response. High responders should start at seventy-five to one hundred and fifty international units per day, not the two hundred and fifty unit dose that an average responder gets. Over-dosing a high responder is the most common preventable cause of OHSS in clinics where this lever is not used carefully.

What to do at home if you have mild OHSS

Mild OHSS is managed at home with clinic guidance. The basic approach has not changed much in twenty years.¹

Weigh yourself daily at the same time, on the same scale, in the same clothing. Track the trend, not the absolute number. A rise of more than a kilogram in twenty-four hours is the threshold to call the clinic.

Drink electrolyte fluids, not just water. Coconut water, oral rehydration solutions, and broth all do better at replacing the electrolytes that shift in OHSS than plain water does. Plain water in large volumes can actually worsen the picture.

Eat a high-protein diet, aiming for roughly one and a half grams per kilogram body weight per day. Some evidence suggests protein helps maintain intravascular oncotic pressure and reduces fluid shift, though the evidence base is modest. It is unlikely to harm.

Avoid non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen unless your reproductive endocrinologist (RE) clears them. NSAIDs can affect renal perfusion in OHSS and are best avoided. Paracetamol is the preferred analgesic.

Wear compression stockings if your mobility is reduced. The combination of high oestrogen, fluid shift, and reduced movement raises the DVT risk meaningfully. Walk gently around the house several times a day.

Track your twenty-four-hour fluid intake and urine output if your clinic asks. A simple jug on the bathroom counter for measured urine collection works.

What to avoid after egg retrieval

This is a frequent search and worth being clear about. After retrieval, regardless of OHSS risk, I ask patients to avoid: alcohol, NSAIDs, hot baths and saunas, vigorous exercise, twisting motions, heavy lifting, and intercourse for at least the first two weeks. Air travel during the first week is also discouraged because ovaries are still enlarged and torsion risk is not zero. Once you are past two weeks and feeling well, most of these restrictions lift.

If you are at high OHSS risk specifically, add: no air travel for ten to fourteen days post-trigger, no vigorous exercise for two to three weeks, and prompt reporting of any escalating symptoms.

When to call vs when to go to the emergency room

This is the threshold most readers want spelled out cleanly.

Call your clinic for weight gain of one to two kilograms in twenty-four hours, increasing abdominal pain, decreased urine output, persistent nausea, mild shortness of breath with exertion, or any concern that does not feel right.

Go to the emergency room for severe abdominal pain not relieved by paracetamol, shortness of breath at rest, weight gain of more than three kilograms in twenty-four hours, persistent vomiting for more than twelve hours preventing fluid intake, fainting, chest pain, calf swelling or pain, or severely reduced urine output. If your clinic on-call line is not answering and any of these are present, go.

Do not feel embarrassed about presenting to the emergency room. Severe OHSS is genuinely a medical emergency and the patients who delay are the ones who end up sicker.

After OHSS, what changes for cycle two

If you have had any OHSS in a prior cycle, even mild, the planning for cycle two should look different. The conversation with your RE should cover:

1. A lower starting gonadotropin dose, matched to your AMH and AFC.
2. An antagonist protocol if you were not already on one.
3. Agonist or dual trigger from the start, not as a rescue if estradiol climbs.
4. Freeze-all rather than fresh transfer.
5. Cabergoline from trigger day for around eight days.
6. Possibly a slightly lower target follicle count, accepting fewer eggs in exchange for a much smaller risk of recurrence.

This is not a less-aggressive approach. It is a smarter approach for your specific biology.

What to ask your RE before stim

These five questions are the right ones to bring to the planning visit if you have any of the risk factors above.

1. What is my OHSS risk based on my AMH, AFC, and PCOS status?
2. What trigger are you planning, and at what estradiol or follicle count would you switch from hCG to agonist or dual?
3. Will we freeze all if I am high risk?
4. Will I be on cabergoline post-trigger?
5. What is the after-hours number, and which OHSS symptoms after egg retrieval warrant calling tonight versus waiting until morning?

What's next

• If you want the broader picture of stim and what it feels like day by day: IVF Stimulation Phase: What the 10 to 14 Days Actually Feel Like
• If you have PCOS or a high AMH and want to understand why your biology lands you in this category: Why PCOS Patients Get More Eggs and the OHSS Risk
• If you want to understand the protocols that prevent OHSS: Common IVF Stim Protocols: Long, Short, Antagonist Explained
• If you are about to start injections: Injections in IVF: Self-Injecting and What to Expect
• If your cycle was cancelled because of OHSS risk: When Things Don't Go to Plan

Sources

1. Practice Committee of the American Society for Reproductive Medicine. Prevention and treatment of moderate and severe ovarian hyperstimulation syndrome: a guideline. Fertility and Sterility 2016;106(7):1634-1647. https://doi.org/10.1016/j.fertnstert.2016.08.048
2. Tang H, Mourad S, Zhai SD, Hart RJ. Dopamine agonists for preventing ovarian hyperstimulation syndrome. Cochrane Database of Systematic Reviews 2021;4:CD008605. https://doi.org/10.1002/14651858.CD008605.pub4
3. Engmann L, DiLuigi A, Schmidt D, et al. The use of GnRH agonist to induce oocyte maturation after cotreatment with GnRH antagonist in high-risk patients undergoing IVF prevents the risk of ovarian hyperstimulation syndrome. Fertility and Sterility 2008;89(1):84-91. https://doi.org/10.1016/j.fertnstert.2007.02.002
4. Devroey P, Polyzos NP, Blockeel C. An OHSS-free clinic by segmentation of IVF treatment. Human Reproduction 2011;26(10):2593-2597. https://doi.org/10.1093/humrep/der251
5. Royal College of Obstetricians and Gynaecologists. The Management of Ovarian Hyperstimulation Syndrome. Green-top Guideline No. 5. 2016. https://www.rcog.org.uk/guidance/browse-all-guidance/green-top-guidelines/the-management-of-ovarian-hyperstimulation-syndrome-green-top-guideline-no-5/
6. Humaidan P, Quartarolo J, Papanikolaou EG. Preventing ovarian hyperstimulation syndrome: guidance for the clinician. Fertility and Sterility 2010;94(2):389-400. https://doi.org/10.1016/j.fertnstert.2010.03.028