How do I calculate my IVF due date after embryo transfer?

Use the **transfer date** on your clinic summary and **embryo stage at transfer**: **Day 5 blastocyst** → add **261 days**; **Day 3** → add **263 days**; **egg retrieval** (if dating from retrieval) → add **266 days**. These offsets align with the standard **280-day pregnancy from LMP** model because IVF knows “conception equivalent” precisely. Enter your date and method in the calculator above for EDD, equivalent LMP, gestational age today, and trimester end dates. Your OB may still adjust after the **6–7 week ultrasound** if crown–rump length (CRL) differs.

Why is an IVF due date more accurate than using my last period?

Natural-cycle due dates assume ovulation on **cycle day 14**, but many people ovulate earlier or later, have **irregular cycles**, or do not remember LMP exactly. In IVF, **retrieval date** equals fertilization day and **transfer date** plus **embryo age** (3 or 5 days in the lab) defines development. That removes ovulation guesswork, so IVF-dated pregnancies often match early ultrasound better than LMP alone—especially after **FET** where there is no fresh retrieval in the same month as transfer.

What is the difference between Day 3 and Day 5 embryo transfer due dates?

A **Day 3** embryo has grown **3 days** after fertilization; a **Day 5 blastocyst** has grown **5 days**. Gestational age counts from equivalent LMP, which is **14 days before conception equivalent**. So Day 3 transfer EDD = transfer date **+ 263 days**; Day 5 = **+ 261 days** (2 days earlier EDD for Day 5 because the embryo is “older”). Clinically, **blastocyst (Day 5–7)** transfers are standard for many programs because they better select viable embryos; dating math still depends on the **documented transfer day**, not PGT status.

Is frozen embryo transfer (FET) due date calculated differently than fresh IVF?

**No difference in the formula**—only **transfer date** and **embryo age at transfer** matter. Fresh and frozen **Day 5** transfers both use **+261 days** from transfer. Frozen cycles may use **medicated** or **natural** FET protocols, but obstetric dating does not change. What changes is **beta-hCG timing** (same ~9–12 days post-transfer for Day 5) and sometimes **lining prep** medications—not the 40-week calendar. Always use the **actual transfer date**, not the thaw date alone if they differ on paperwork.

How are Day 6 or Day 7 blastocyst transfers dated?

Blastocysts that develop on **Day 6 or 7** are still blastocyst-stage embryos; many clinics **date them like Day 5** (+261 days) because implantation biology aligns with blastocyst age, not the extra culture day. This calculator offers **Day 6** as **+260 days** (strict embryo age). If your clinic letter says “treat as Day 5 for dating,” use the **Day 5** option even for a Day 6 embryo. When in doubt, ask your REI which offset they put in your chart—it should match the **ultrasound** at 6–7 weeks.

How do I calculate gestational age after IVF?

Obstetric **gestational age (GA)** is measured from **LMP**, not conception. IVF converts your event to an **equivalent LMP**: subtract **embryo age** and **14 days** from transfer (or subtract 14 days from retrieval). Then count days from that LMP to today → **weeks + days** (e.g. 6w 2d). The form shows “gestational age today” automatically. **Conceptional age** is ~2 weeks less than GA. IVF patients often hear “you’re 6 weeks” at first ultrasound—that means **6 weeks GA (4 weeks from conception)**.

Can my IVF due date change after ultrasound?

**Yes, sometimes.** IVF EDD is strong early, but **first-trimester CRL** is the most accurate biometric for dating. If ultrasound GA differs from IVF dating by **more than ~5–7 days**, many clinicians **adjust the official EDD** to match CRL—especially if LMP was unknown or IVF paperwork used the wrong transfer day. Small differences are common and may not change management. **Non-viable** pregnancies or **vanishing twin** can also complicate early measurements; follow your fertility clinic until **discharge to OB**.

When should I take a pregnancy test after Day 5 embryo transfer?

Most programs schedule **serum beta-hCG** **9–12 days** after **Day 5** transfer (some wait until **12–14 days** to reduce false negatives). **Home urine tests** may turn positive a day or two earlier but can be fooled by **trigger shot hCG** (Ovidrel) if used—blood testing is definitive. If positive, clinics often repeat beta in **48–72 hours** looking for **≥53% rise** when still early. Use our **HCG Weeks Calculator** for level-to-week teaching; do not use urine tests to date pregnancy precisely.

Does ICSI or PGT-A change my due date?

**No.** **ICSI** is a fertilization technique; **PGT-A** is embryo genetic testing before transfer. Neither changes **how many days** to add from transfer. **Single vs double embryo transfer** does not change maternal due date (twins may deliver earlier clinically but EDD math is the same). **Donor egg** cycles still date from **recipient transfer** or **recipient retrieval** per clinic policy—the recipient’s LMP is not used if transfer-based dating is documented.

Egg retrieval due date vs transfer due date — which should I use?

Use **one consistent anchor** your clinic documents. **Retrieval + 266 days** dates pregnancy from fertilization day (same as “conception” in IVF). If you had **freeze-all** and a later **FET**, date from **FET transfer** (Day 5 → +261), not retrieval—otherwise you will be ~2+ weeks off. Fresh transfers without freeze: retrieval and transfer dating are internally consistent if you apply the right offset. Your discharge summary usually states the **official EDD**—match that method here.

What milestones should I track after IVF transfer?

Typical sequence: **(1)** Post-transfer medications (progesterone, estrogen, sometimes blood thinners) per protocol; **(2)** **Beta-hCG** blood test; **(3)** Repeat beta if early or uncertain; **(4)** **6–7 week ultrasound** for location, heartbeat, and dating; **(5)** Graduation from **REI to OB** ~8–10 weeks; **(6)** NT/anatomy scans on OB schedule. Bleeding or severe pain before ultrasound requires **urgent** fertility or ER evaluation for **ectopic** exclusion. Pair this calendar with our **IVF Success Rate Calculator** for planning prior cycles—not after you are pregnant.

Is this IVF due date calculator medical advice?

No. It applies standard **obstetric offsets** for education. Your fertility clinic’s documented EDD and ultrasound measurements override any online tool. Seek emergency care for **heavy bleeding**, **severe one-sided pain**, **shoulder pain**, fainting, or fever during stimulation or early pregnancy.

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IVF & early pregnancy

IVF Due Date Calculator

Calculate your IVF due date from Day 5 FET, Day 3 fresh transfer, Day 6 blastocyst, or egg retrieval. See gestational age, equivalent LMP, trimester end dates, and beta-hCG timing—more precise than period-based dating when transfer day is known. More on our medical calculators hub.

Last updated: June 4, 2026

Day 3, Day 5, Day 6 & retrieval formulas

Fresh IVF and frozen embryo transfer (FET)

EDD, GA today, and trimester milestones

IVF Due Date Calculator

Due date and gestational age from retrieval or embryo transfer date

Calculation method

Embryo transfer date

Estimated due date (EDD)

Thu, November 26, 2026

Gestational age today: 16w 2d (LMP-based weeks)

Milestones (from equivalent LMP)

Conception / retrieval equivalentThu, March 5, 2026

Equivalent LMP (for OB charts)Thu, February 19, 2026

End of 1st trimester (~14 wks)Wed, May 27, 2026

End of 2nd trimester (~28 wks)Wed, September 2, 2026

Formula: transfer/retrieval date + 261 days (Day 5 blastocyst transfer). Confirm with ultrasound if growth differs.

Educational dating only. Your fertility clinic's documented EDD and first-trimester ultrasound crown–rump length override online estimates. Day 7 embryos are often charted as Day 5—confirm with your REI.

Example due dates (from calculator logic)

Day 5 · Mar 10, 2026

Thu, November 26, 2026

+261 days from transfer

Day 3 · Apr 2, 2026

Mon, December 21, 2026

Retrieval · Jan 18, 2026

Sun, October 11, 2026

Day 6 · Feb 20, 2026

Sat, November 7, 2026

Some clinics use Day 5 (+261) instead

IVF due date formulas (transfer & retrieval)

Standard pregnancy length from LMP = 280 days (40 weeks). Conception equivalent ≈ LMP + 14 days.

Retrieval / IUI: procedure date + 266 days

Day 3 transfer: transfer date + 263 days

Day 5 transfer (FET/fresh): transfer date + 261 days

Day 6 transfer: transfer date + 260 days

Why 261 for Day 5? A Day 5 embryo is 5 days post-fertilization; adding 261 days to transfer equals 266 days from fertilization—the same as retrieval dating.

Transfer type comparison — formula, beta-hCG & ultrasound

IVF event	EDD formula	Beta-hCG (typical)	First ultrasound (GA)	Notes
Egg retrieval / IUI	+266 days	~12–16 days after retrieval	~6–7 weeks GA (LMP weeks)	Retrieval = “conception day” in IVF dating (cycle day 14 equivalent)
Day 3 transfer (cleavage)	+263 days	~11–14 days post-transfer	~6–7 weeks GA from equivalent LMP	Embryo age 3 days at transfer; 2 days “younger” than day 5 for dating
Day 5 blastocyst (fresh or FET)	+261 days	~9–12 days post-transfer	~6–7 weeks GA; often first scan ~2–3 weeks after transfer	Most common for frozen blastocyst transfers
Day 6 blastocyst	+260 days (this tool)	Similar to day 5	Same window; some clinics use +261 like day 5	Day 7 blastocysts often dated as day 5 clinically—confirm with your clinic

LMP dating vs IVF dating

Aspect	LMP-based	IVF-based
Start of pregnancy clock	First day of last menstrual period	Known retrieval or transfer date
Ovulation uncertainty	Assumes day 14 ovulation—can be off ±3–7 days	Eliminated when transfer age is known
Typical accuracy	±1–2 weeks if cycles irregular	Often within a few days until ultrasound revision
First trimester ultrasound	May shift EDD if CRL differs	Still gold standard if fetal size ≠ dated GA

Pregnancy milestones after IVF (gestational age)

4–5 weeks GA:Expected positive home or blood beta-hCG (after appropriate wait)
6–7 weeks GA:Transvaginal ultrasound: sac, yolk sac, fetal pole, cardiac activity
11–14 weeks GA:NT scan / first-trimester screening; end of first trimester ~13+6
18–22 weeks GA:Anatomy ultrasound
40 weeks GA:Estimated due date (delivery window ~37–42 weeks)

Retrieval / IUI

Retrieval day = fertilization. EDD = date + 266 days (280 − 14 from LMP framework).

Day 3 transfer

Cleavage-stage embryo. EDD = transfer + 263 days.

Day 5 / FET

Blastocyst fresh or frozen. EDD = transfer + 261 days—most common search intent.

Worked examples

Day 5 FET

Transfer March 10, 2026

March 10 + 261 days =

Thu, November 26, 2026

Day 3 fresh

Transfer April 2, 2026

Mon, December 21, 2026

Egg retrieval

Retrieval January 18, 2026

Sun, October 11, 2026

Sources & references

After transfer, track beta-hCG with our HCG weeks calculator and plan treatment cycles with the IVF success rate calculator.

Frequently Asked Questions

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IVF & early pregnancy

IVF Due Date Calculator

Last updated: June 4, 2026

Day 3, Day 5, Day 6 & retrieval formulas

Fresh IVF and frozen embryo transfer (FET)

EDD, GA today, and trimester milestones

IVF Due Date Calculator

Due date and gestational age from retrieval or embryo transfer date

Calculation method

Embryo transfer date

Estimated due date (EDD)

Thu, November 26, 2026

Gestational age today: 16w 2d (LMP-based weeks)

Milestones (from equivalent LMP)

Conception / retrieval equivalentThu, March 5, 2026

Equivalent LMP (for OB charts)Thu, February 19, 2026

End of 1st trimester (~14 wks)Wed, May 27, 2026

End of 2nd trimester (~28 wks)Wed, September 2, 2026

Formula: transfer/retrieval date + 261 days (Day 5 blastocyst transfer). Confirm with ultrasound if growth differs.

Example due dates (from calculator logic)

Day 5 · Mar 10, 2026

Thu, November 26, 2026

+261 days from transfer

Day 3 · Apr 2, 2026

Mon, December 21, 2026

Retrieval · Jan 18, 2026

Sun, October 11, 2026

Day 6 · Feb 20, 2026

Sat, November 7, 2026

Some clinics use Day 5 (+261) instead

IVF due date formulas (transfer & retrieval)

Standard pregnancy length from LMP = 280 days (40 weeks). Conception equivalent ≈ LMP + 14 days.

Retrieval / IUI: procedure date + 266 days

Day 3 transfer: transfer date + 263 days

Day 5 transfer (FET/fresh): transfer date + 261 days

Day 6 transfer: transfer date + 260 days

Why 261 for Day 5? A Day 5 embryo is 5 days post-fertilization; adding 261 days to transfer equals 266 days from fertilization—the same as retrieval dating.

Transfer type comparison — formula, beta-hCG & ultrasound

IVF event	EDD formula	Beta-hCG (typical)	First ultrasound (GA)	Notes
Egg retrieval / IUI	+266 days	~12–16 days after retrieval	~6–7 weeks GA (LMP weeks)	Retrieval = “conception day” in IVF dating (cycle day 14 equivalent)
Day 3 transfer (cleavage)	+263 days	~11–14 days post-transfer	~6–7 weeks GA from equivalent LMP	Embryo age 3 days at transfer; 2 days “younger” than day 5 for dating
Day 5 blastocyst (fresh or FET)	+261 days	~9–12 days post-transfer	~6–7 weeks GA; often first scan ~2–3 weeks after transfer	Most common for frozen blastocyst transfers
Day 6 blastocyst	+260 days (this tool)	Similar to day 5	Same window; some clinics use +261 like day 5	Day 7 blastocysts often dated as day 5 clinically—confirm with your clinic

LMP dating vs IVF dating

Aspect	LMP-based	IVF-based
Start of pregnancy clock	First day of last menstrual period	Known retrieval or transfer date
Ovulation uncertainty	Assumes day 14 ovulation—can be off ±3–7 days	Eliminated when transfer age is known
Typical accuracy	±1–2 weeks if cycles irregular	Often within a few days until ultrasound revision
First trimester ultrasound	May shift EDD if CRL differs	Still gold standard if fetal size ≠ dated GA

Pregnancy milestones after IVF (gestational age)

4–5 weeks GA:Expected positive home or blood beta-hCG (after appropriate wait)
6–7 weeks GA:Transvaginal ultrasound: sac, yolk sac, fetal pole, cardiac activity
11–14 weeks GA:NT scan / first-trimester screening; end of first trimester ~13+6
18–22 weeks GA:Anatomy ultrasound
40 weeks GA:Estimated due date (delivery window ~37–42 weeks)