Due date from a day-3 or day-5 embryo transfer, using the ACOG offsets of 263 and 261 days
Runs in your browser. Nothing you type is sent anywhere. Checked against sources on 29 Sept 2026.After IVF the due date comes from the transfer date and the embryo’s age, not from a period. The American College of Obstetricians and Gynecologists puts it 263 days after a day-3 transfer and 261 days after a day-5 blastocyst transfer.
IVF transfer is already selected under "Method".
Enter the "Embryo transfer date" from your clinic note.
Under "Embryo age at transfer", pick Day 3 or Day 5 (blastocyst).
Read the Estimated due date and Days to go, then press Share result to copy a link.
Enter the transfer date and embryo day to see the due date, today’s week of pregnancy, and each milestone on the calendar.
A due date is a dating convention, not a forecast. The one most people are given comes from Naegele's rule: 280 days, or 40 weeks, from the first day of the last menstrual period. That rule assumes a 28-day cycle with ovulation around day 14, so this page moves the date by one day for every day your regular cycle runs longer or shorter than 28. A 32-day cycle gives a due date four days later.
Two other starting points are offered. From a known conception date the due date is 266 days on, the same 38 weeks with the two pre-ovulation weeks removed. After IVF, the American College of Obstetricians and Gynecologists (Committee Opinion No. 700) dates the pregnancy from the embryo's age at transfer: 263 days after a day-3 transfer and 261 days after a day-5 transfer.
What this tool does not do matters more than what it does. It cannot see the pregnancy. A first-trimester ultrasound is the most accurate way to date one, and once a clinician has set a date from a scan, that date replaces anything worked out here. The period method is unreliable for irregular cycles, after recent hormonal contraception, or when the date of the last period is uncertain. Most babies are not born on their due date; a normal pregnancy runs anywhere from 37 to 42 weeks.
The rest of the article, and all 6 questions about Pregnancy Due Date Calculator, are on the Pregnancy Due Date Calculator page.
Naegele's rule adds 280 days, or 40 weeks, to the first day of the last period. A last period starting on 1 January 2026 gives a due date of 8 October 2026. For a regular cycle longer or shorter than 28 days, the date moves by the difference, so a 32-day cycle adds four days.
The first day of a period is a date most people know, while the day of conception usually is not. Counting from the period adds about two weeks before conception, so at 8 weeks pregnant the embryo is roughly 6 weeks old. Scans and antenatal notes use the same period-based count.
ACOG Committee Opinion No. 700 dates an IVF pregnancy from the embryo transfer. The due date is 263 days after transferring a day-3 embryo and 261 days after a day-5 blastocyst. A frozen transfer uses the same offsets, counted from the transfer date rather than from any period.
ACOG Committee Opinion No. 579 labels a pregnancy early term from 37 weeks 0 days, full term from 39 weeks 0 days, late term from 41 weeks 0 days and postterm from 42 weeks 0 days. The milestone table on this page gives the calendar date on which each label begins.
Rates and rules change; check the source before you rely on a figure.
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