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OHSS risk factors calculator

Am I at risk of OHSS?

Which recognised OHSS risk factors apply to you, and what to ask your clinic about each.

AMH

ng/mL

Leave at 0 if you do not know it

Antral follicle count

follicles

Total across both ovaries. 0 if unknown

Your age

years

PCOS diagnosed

1 = yes, 0 = no

Follicles at trigger

follicles

Number 11mm or larger. 0 if not yet at trigger

These are example numbers. Replace them with yours, then press Calculate.

Example answer

0risk factors present

no listed factors

None of the recognised baseline risk factors apply. OHSS is uncommon in this group, though not impossible — monitoring during stimulation is still what catches it. Know the warning signs regardless.

This is a guide, not a diagnosis. Share the result with your doctor.

Your result on the scale

The ranges this calculator uses. Yours is highlighted.

Your numbers

Everything worked out from what you entered.

AMH at or above 3.4 ng/mL: not present (2.5)
Antral follicle count 24 or more: not present (12)
Age under 30: not present (32)
PCOS: not present
19 or more follicles at trigger: not yet at trigger

What each result means

Your result is highlighted. Your own clinic's advice always comes first.

Your resultno listed factors

Your resultone factor

One recognised factor. Worth naming it to your clinic before stimulation starts, so the starting dose and trigger choice take it into account.

Your resulttwo factors

Raised risk. This is the point at which a GnRH agonist trigger instead of hCG, and a freeze-all rather than a fresh transfer, are commonly discussed. Ask specifically about both.

Your resultthree or more factors

High risk. An agonist trigger with a freeze-all strategy substantially reduces severe OHSS and is standard practice for high responders. Ask your clinic what they plan to do differently, and make sure you have a number to call after egg collection.

Where this fits in your journey

The usual order, from trying to conceive to pregnancy. Not everyone needs every stage. This calculator belongs to stage 4.

Stage 4 · you are here

During an IVF cycle

Make sense of the numbers your clinic gives you.

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Egg collection
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Your embryos

This calculator: Am I at risk of OHSS?

Calculators for what comes next

How this is worked out

Compared to published rangesYour values checked against published reference limits. The source is named below; laboratory methods vary.

Ovarian hyperstimulation syndrome is largely predictable and largely preventable. This checks which recognised risk factors you carry, so you can raise them before your trigger rather than afterwards.

About this calculator

?What it tells you

Risk factors to discuss before your trigger. Which recognised OHSS risk factors apply to you, and what to ask your clinic about each.

✓When to use it

Never — assessed by your clinician from monitoring data

iWhat you need

AMH (ng/mL)
Antral follicle count (follicles)
Your age (years)
PCOS diagnosed (1 = yes, 0 = no)
Follicles at trigger (follicles)

!What it cannot tell you

A risk-factor check, not a prediction. It recommends no medication and no dose; those decisions belong to your clinician with your monitoring data.

Common questions

What are the warning signs I should act on?

Rapid weight gain, severe or worsening bloating, breathlessness or difficulty lying flat, marked reduction in how much you are passing urine, severe abdominal pain, or calf pain and swelling. Any of these after egg collection needs urgent contact with your clinic or emergency care — do not wait for a routine appointment.

How is OHSS actually prevented?

Mainly by changing the trigger and delaying transfer. A GnRH agonist trigger instead of hCG, combined with freezing all embryos and transferring in a later cycle, substantially reduces severe OHSS in high responders. A lower starting gonadotropin dose also helps.

I have PCOS. Does that mean I will get OHSS?

No. PCOS raises the risk and is the most common single factor, but most women with PCOS complete IVF without OHSS — particularly where an agonist trigger and freeze-all are used. It is a reason to plan differently, not a reason to avoid treatment.

Does a freeze-all remove the risk completely?

It reduces it substantially but does not abolish it. Early OHSS can still occur after an agonist trigger, and PCOS remains the commonest factor in those cases. The warning signs still matter.

Can I use this instead of monitoring?

No. This uses baseline factors known before or during stimulation. What actually catches developing OHSS is ultrasound and blood monitoring through the cycle, and how you feel after egg collection.

Sources

Recognised risk factors from the ASRM guideline on prevention of moderate and severe OHSS (2023) and published prediction studies: AMH above roughly 3.4 ng/mL, antral follicle count above 24, younger age, PCOS, and 19 or more follicles of 11mm or larger at trigger. Oestradiol at trigger is also used, though follicle number predicts better. This counts recognised factors — it does not estimate a probability, and it cannot replace monitoring during your cycle.

ASRM Practice Committee documents

In an emergency

If you have any of the warning signs listed here, don't wait for a test result or a calculator. Get help now.

112All emergencies, anywhere in India 108Ambulance

Also call your IVF clinic. Most clinics give an emergency number on your treatment or discharge sheet. Save it in your phone now, before you need it.