Estimate how soon ovulation may return after IUD removal using device type, time in place, age, and whether a period has returned. See month-by-month probability, first period window, TTC guidance, earliest test timing, and care flags.
What this estimates
The tool gives an educational timeline for return to ovulation after IUD removal and the first natural period. It shows a median and middle fifty percent range, the probability that ovulation has returned by a given month, a simple fertile window, an earliest reliable test day, and a care threshold if periods have not returned.
Data model
- Distribution: months to ovulation after removal is modelled with a log-normal curve.
- Baselines: hormonal IUD median 1.5 months, copper IUD median 1.0 month. Shape parameter sigma 0.40.
- Modifiers to the median (added in months):
- Years in place: +0.05 per year, cap +0.5.
- Age 35–39: +0.2. Age 40 plus: +0.5.
- BMI band: underweight +0.1, overweight +0.2, obese +0.5.
- Cycles irregular before IUD: +0.4.
- Period already returned after removal: −0.8, floor 0.5 months.
- Copper minimum floor 0.6 months.
- Probability by month X: round months since removal to the nearest month and apply the log-normal CDF.
- Date mapping: convert months to days with 30 days per month.
- First period window: ovulation quartiles + 14 days (window from 25th to 75th percentile).
- Fertile window: five days centred on the median ovulation date (two days before to two days after).
- Earliest reliable test day: earliest ovulation in the window + 10 days.
- Care threshold: if no period by 4 months after hormonal IUD removal or 3 months after copper removal, bring review forward by one month at age 40 plus.
Inputs and validation
- IUD type, removal date, years in place, age.
- Optional: whether a period has returned (date if yes), cycle length, BMI band, previous cycle pattern, free-text reason.
- Bounds: years in place 0 to 15, age 15 to 55, cycle length 21 to 45.
Limits
This is a stylised model for education. It does not replace clinical assessment or clinic-specific guidance. Hormone withdrawal bleeding can occur without ovulation. Individual variation is common after device removal.
Sources
- ACOG, Long-acting reversible contraception (IUDs and implants): outlines quick return to fertility after removal.
- CDC, U.S. Selected Practice Recommendations for Contraceptive Use: clinical guidance on initiation, removal, and return to fertility.
- FSRH, Intrauterine contraception guideline: return to fertility after intrauterine methods.
- WHO, Medical eligibility criteria for contraceptive use: background on intrauterine methods and fertility after discontinuation.
What each input means
- IUD type: Choose Hormonal (Mirena, Kyleena, Skyla, Liletta) or Copper (ParaGard). Type is used to shape the return-to-ovulation curve.
- Removal date: Date the IUD was removed. Dates display in the format 01 Jan 2025.
- Years in place: Total time the IUD was in use. Used for context in the estimates.
- Reason for removal (optional): For your records and tips. Does not diagnose conditions.
- Period returned since removal? Select Yes or No. If Yes, add the date. A recent period suggests ovulation has resumed.
- Age: Used for context and care-flag thresholds.
- BMI band (optional): Additional context only.
- Cycle regularity before IUD: Regular or irregular before insertion. Helps shape windows if periods have not yet returned.
How to read the results
- Time to ovulation: Median months from removal with a 25–75th percentile band. Also shows the probability that ovulation has returned by any selected month.
- First period window: A date range for when your first natural period is expected, based on the ovulation estimate.
- TTC guidance (first 3 cycles): Brief pointers for timing sex in the likely fertile windows during the first three cycles.
- Earliest reliable test day: The first day many home tests are more reliable, usually after your period window ends.
- Care flag: A prompt such as "See a clinician if no period by X months," where X varies by IUD type and age.
- Timeline chart: A simple visual from removal to the ovulation and first-period percentiles.
If periods have not returned and the model confidence is low, the tool will show wider windows and suggest when to follow up.
Frequently asked questions
Can ovulation happen before the first natural period after IUD removal?
Yes. The calculator shows how soon this is likely in your case and when to test.
Does hormonal vs copper IUD change the timeline?
Type is used in the estimate. Individual return varies.
Do years in place affect return to cycles?
Longer use can be associated with a longer return for some people. The timeline reflects your inputs.
Can we try before the first period?
Yes. Timing sex in likely fertile windows may help even before the first period returns.
When should I see a clinician after removal?
Follow the care flag in your result. Seek care sooner if you have symptoms or concerns.