IVF Due Date Calculator

What Is the IVF Due Date Calculator?

The IVF Due Date Calculator estimates your expected date of delivery (EDD) using inputs unique to assisted reproduction: egg retrieval or insemination date, embryo transfer date, and embryo age at transfer (e.g., day-3 cleavage or day-5 blastocyst). Unlike standard “LMP + 280 days,” this calculator first converts your IVF timeline to an adjusted last menstrual period (aLMP), then applies the same 40-week obstetric convention used by clinicians. You’ll see exactly how each step is computed, with MathJax/KaTeX-ready formulas so the math scales cleanly on any screen. Results are estimates; ultrasound dating and your clinician’s guidance always take precedence.

About the IVF Due Date Calculator

In obstetrics, gestational age counts from the LMP, two weeks before ovulation. In IVF, we can reconstruct an equivalent LMP from known events. The core ideas:

• aLMP from Retrieval: retrieval (or fertilization) approximates conception; subtract 14 days to get aLMP.
• aLMP from Transfer: transfer date minus (embryo age + 14) days equals aLMP.
• EDD: aLMP plus 280 days (40 weeks).
• Gestational Age (any day): days since aLMP, expressed in weeks + days.

This approach supports fresh cycles, frozen embryo transfers (FET), donor eggs, and embryos of different ages (day-3, day-5, day-6). Because scan-based dating may adjust by a few days, treat the output as a planning estimate for milestones, travel, and leave.

How to Use This IVF Due Date Calculator

1. Choose your reference: egg retrieval/fertilization date or embryo transfer date plus embryo age (3, 5, or 6).
2. Enter the date(s) exactly as on your clinic schedule.
3. Optionally record the cycle type (fresh, FET) and notes like first β-hCG for your records.
4. Review the computed aLMP, EDD, and (optionally) gestational age for any calendar date you select.

Tip: For day-5 transfers, most people use Transfer + 261 days as a quick mental EDD check.

Formulas (MathJax/KaTeX-ready & responsive)

Adjusted LMP (aLMP)

\( \displaystyle \text{aLMP}_{\text{retrieval}} = \text{Retrieval} - 14\ \text{days} \)

\( \displaystyle \text{aLMP}_{\text{transfer}} = \text{Transfer} - \big(e + 14\big)\ \text{days} \quad (e=\text{embryo age in days}) \)

Expected Due Date (EDD)

\( \displaystyle \text{EDD} = \text{aLMP} + 280\ \text{days} \)

Equivalently from transfer: \( \displaystyle \text{EDD} = \text{Transfer} + \big(266 - e\big)\ \text{days} \)

Special cases: day-3 ⇒ \(266-3=263\) days; day-5 ⇒ \(266-5=261\) days; day-6 ⇒ \(260\) days.

Gestational Age (GA) on a given date \(D\)

\( \displaystyle \text{GA}_{\text{days}} = D - \text{aLMP} \quad;\quad \text{GA}_{\text{weeks}}=\left\lfloor \frac{\text{GA}_{\text{days}}}{7} \right\rfloor,\ \text{GA}_{\text{rem}}=\text{GA}_{\text{days}} \bmod 7 \)

Examples (Using the Same Formulas)

Example A — Retrieval Based

Retrieval = 1 Mar 2025.
aLMP = 1 Mar 2025 − 14 days = 15 Feb 2025.
EDD = aLMP + 280 days = 22 Nov 2025.

Example B — Day-5 FET

Transfer = 10 Apr 2025, \( e=5 \).
EDD = Transfer + (266 − 5) = Transfer + 261 days = 27 Dec 2025.
aLMP = Transfer − (5 + 14) = 22 Mar 2025.

Example C — Day-3 Transfer

Transfer = 20 May 2025, \( e=3 \).
EDD = Transfer + (266 − 3) = +263 days = 7 Feb 2026.

FAQs