# IVF due date after a day-5 blastocyst transfer

Transfer date plus 261 days. IVF dating is the most precise there is, and a later scan should not override it.

**Estimated due date 2025-10-08 — currently 10w3d, with 207 days to go.**

> This is arithmetic on the dates you supplied, not medical advice. It cannot see an ultrasound, a chart, or a person. Clinical dating is done by a qualified clinician, and an estimated due date is an estimate — most births do not happen on it. Nothing here should change what you do without talking to your own clinician.

## Estimate

| | |
| --- | --- |
| Estimated due date | **2025-10-08** |
| Method | IVF, day-5 blastocyst transfer |
| Gestational age on 2025-03-15 | 10w3d |
| Days remaining | 207 |
| Trimester | 1 |
| Estimated conception | 2025-01-15 |

## Milestones

| Date | Gestational age | Milestone | Note |
| --- | --- | --- | --- |
| 2025-04-08 | 13w6d | End of first trimester | Also the last point at which ultrasound dating is at its most accurate. |
| 2025-05-07 | 18w0d | Anatomy scan window opens | The detailed anatomy scan is usually done between 18 and 22 weeks. |
| 2025-06-04 | 22w0d | Anatomy scan window closes | After this the standard views become harder to obtain. |
| 2025-07-15 | 27w6d | End of second trimester | The third trimester begins the following day. |
| 2025-09-17 | 37w0d | Early term begins | ACOG classifies 37w0d to 38w6d as early term, not full term. |
| 2025-10-01 | 39w0d | Full term begins | Full term runs 39w0d to 40w6d. |
| 2025-10-08 | 40w0d | Estimated due date | A reference point, not a prediction. Most births are not on this day. |
| 2025-10-22 | 42w0d | Post-term begins | From 42w0d a pregnancy is classified post-term. |

## Read before relaying this

### Gestational age counts from the last period, not from conception (caution)

This is the most misunderstood fact in the subject. The 40-week clock starts at the first day of the last menstrual period, roughly two weeks BEFORE conception. So at 10w3d the pregnancy is about 8w3d since conception. Weeks 1 and 2 of a pregnancy are, by this convention, before there is a pregnancy.

**What to do:** When comparing against a known conception or transfer date, use that method instead — it does not go through the two-week offset.

### The due date is a reference point, not a prediction (caution)

Only a small minority of births happen on the estimated date. The useful output is the term windows — early term from 37w0d, full term from 39w0d — not the single day.

### IVF dating should not be overridden by ultrasound (info)

When the date of fertilisation and transfer is known exactly, the estimate is more precise than any ultrasound measurement, and ACOG guidance is that it should be used regardless of what a later scan measures.

### Not medical advice (info)

This is arithmetic on the dates you supplied, not medical advice. It cannot see an ultrasound, a chart, or a person. Clinical dating is done by a qualified clinician, and an estimated due date is an estimate — most births do not happen on it. Nothing here should change what you do without talking to your own clinician.

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Canonical URL: https://due-date.gumballtools.com/dating/ivf-due-date-day-5-transfer
JSON API: `GET https://due-date.gumballtools.com/api/v1/estimate?method=lmp&date=YYYY-MM-DD`
MCP endpoint: `https://due-date.gumballtools.com/api/mcp`