IVF Due Date Calculator – Estimate Delivery Date from Transfer
Estimated Due Date
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Gestational Age Today
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Equivalent LMP Date
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Trimester Timeline
Key Milestones
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How IVF Due Date Calculation Works
An IVF due date calculator estimates the expected delivery date based on the embryo transfer date and the developmental stage of the embryo at transfer. Unlike natural conception, where the due date is estimated from the last menstrual period (LMP) with an assumed ovulation on day 14, IVF provides the exact fertilization date and embryo age. According to the American College of Obstetricians and Gynecologists (ACOG), IVF-derived due dates are the most accurate gestational dating method available because they eliminate the uncertainty of natural conception timing.
This calculator determines your theoretical LMP date from the transfer date and embryo age, then projects the due date at 40 weeks (280 days) from that LMP. It also shows your current gestational age, trimester timeline, and key milestones. For related pregnancy planning, see our General Due Date Calculator and Pregnancy Weight Gain Calculator.
The IVF Due Date Formula
The formulas used for IVF due date calculation are standardized across fertility clinics worldwide:
Equivalent LMP = Transfer Date - (14 + Embryo Age in Days)
Due Date = Equivalent LMP + 280 days
For a Day 5 blastocyst transfer, the LMP equivalent is the transfer date minus 19 days (14 days for the assumed follicular phase + 5 days of embryo age). For a Day 3 transfer, subtract 17 days. For a Day 6 blastocyst, subtract 20 days.
Worked example: A Day 5 blastocyst transferred on March 15, 2026. Equivalent LMP = March 15 - 19 days = February 24, 2026. Due date = February 24 + 280 days = December 1, 2026. This is 38 weeks and 2 days from the transfer date, or exactly 40 weeks from the theoretical LMP.
Key Terms You Should Know
- Blastocyst (Day 5/6): An embryo that has developed for 5-6 days after fertilization, containing 70-100+ cells organized into an inner cell mass (future baby) and trophectoderm (future placenta). Blastocyst transfers have higher implantation rates than cleavage-stage transfers.
- Cleavage stage (Day 3): An embryo at 6-8 cells that has undergone several rounds of cell division but has not yet formed a blastocyst cavity. Day 3 transfers are less common today but may be recommended when few embryos are available.
- Gestational age: The age of the pregnancy measured from the first day of the equivalent LMP, not from fertilization. A pregnancy at 8 weeks gestational age has a 6-week-old embryo (gestational age includes the 2-week assumed pre-ovulation period).
- Estimated due date (EDD): The date at which the pregnancy reaches 40 weeks (280 days) from the LMP. Only about 5% of babies arrive on their exact due date; the term window extends from 37 to 42 weeks.
- Fresh vs. frozen transfer: A fresh transfer uses an embryo from the current stimulation cycle. A frozen embryo transfer (FET) uses a previously cryopreserved embryo. The due date calculation is the same for both -- it depends only on the transfer date and embryo age, not on whether the embryo was frozen.
IVF Success Rates by Embryo Transfer Type
The following data reflects national averages from the CDC Assisted Reproductive Technology (ART) Surveillance and the Society for Assisted Reproductive Technology (SART).
| Transfer Type | Embryo Stage | Avg. Implantation Rate | Live Birth Rate (age <35) |
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| Day 3 fresh | Cleavage (6-8 cells) | 25-30% | 35-40% |
| Day 5 fresh | Blastocyst (70-100+ cells) | 40-50% | 45-55% |
| Day 5 frozen (FET) | Cryopreserved blastocyst | 45-55% | 50-60% |
| PGT-tested blastocyst | Euploid blastocyst | 60-70% | 60-70% |
Practical IVF Due Date Examples
Example 1: Day 5 blastocyst transferred on January 10, 2026. LMP = January 10 - 19 = December 22, 2025. Due date = December 22 + 280 = September 28, 2026. First trimester ends March 20. Anatomy scan around May 3. Full term begins September 7.
Example 2: Day 3 embryo transferred on February 20, 2026. LMP = February 20 - 17 = February 3, 2026. Due date = February 3 + 280 = November 11, 2026. The 2-day difference in LMP versus a Day 5 transfer shifts the due date by exactly 2 days earlier.
Example 3: Day 6 blastocyst transferred on April 1, 2026. LMP = April 1 - 20 = March 12, 2026. Due date = March 12 + 280 = December 17, 2026. Day 6 blastocysts are slightly slower to develop but have comparable outcomes to Day 5 transfers in most clinics. Track your pregnancy milestones with our Pregnancy Calculator.
Tips for IVF Pregnancy Planning
- Keep taking prenatal vitamins. Folic acid (at least 400 mcg daily) is critical during the first 12 weeks to prevent neural tube defects. Many fertility specialists recommend 800-1,000 mcg for IVF pregnancies.
- Continue prescribed medications. Most IVF pregnancies require progesterone supplementation (vaginal suppositories, injections, or oral) through weeks 8-12 to support the pregnancy until the placenta takes over hormone production.
- Schedule your first ultrasound at 6-7 weeks. The viability scan confirms a heartbeat and rules out ectopic pregnancy. For IVF pregnancies, this is typically scheduled 2-3 weeks after a positive beta-hCG blood test.
- Understand the due date may shift slightly. While IVF dating is very accurate, your OB may adjust the due date by a few days based on the crown-rump length measurement at the 7-8 week ultrasound. ACOG considers IVF dating accurate to within 5 days.
- Plan for the full-term window, not just the due date. Full term begins at 37 weeks. Only 5% of babies arrive on the exact due date; 80% arrive between 38 and 42 weeks. Have your hospital bag packed by week 36.
Frequently Asked Questions
How is an IVF due date calculated?
An IVF due date is calculated by first determining the equivalent last menstrual period (LMP) date: transfer date minus (14 + embryo age in days). For a Day 5 blastocyst, subtract 19 days from the transfer date. The due date is then 280 days (40 weeks) from this equivalent LMP. For example, a Day 5 transfer on March 15 gives an LMP of February 24 and a due date of December 1. This method is endorsed by ACOG and produces a more accurate due date than natural conception estimates because the exact fertilization timing is known.
Is the IVF due date more accurate than natural conception?
Yes, IVF due dates are the most accurate gestational dating method available. In natural conception, the due date is estimated from the LMP with an assumed ovulation on day 14, which can be off by 1-2 weeks if ovulation occurs earlier or later. With IVF, the exact dates of egg retrieval, fertilization, and embryo transfer are documented, eliminating this uncertainty. ACOG considers IVF dating accurate to within 1-5 days, compared to 5-7 days for first-trimester ultrasound dating and up to 2-3 weeks for LMP-based dating.
What is the difference between Day 3 and Day 5 embryo transfers?
Day 3 embryos (cleavage stage) contain approximately 6-8 cells and have undergone several rounds of cell division but have not yet formed a blastocyst. Day 5 embryos (blastocysts) contain 70-100+ cells organized into distinct structures. Day 5 transfers have higher implantation rates (40-50% vs. 25-30%) because only the strongest embryos survive to the blastocyst stage, providing natural selection. Most modern IVF clinics prefer Day 5 transfers, but Day 3 transfers may be recommended when only 1-2 embryos are available to avoid the risk of no embryos surviving to Day 5 in the lab.
What trimester milestones should I expect?
First trimester (weeks 1-12) includes organ formation, first heartbeat detection at week 6, and the NIPT/NT screening at weeks 10-13. Second trimester (weeks 13-27) brings the anatomy scan at week 18-22, when you can learn the sex and check for structural abnormalities. You will feel fetal movement (quickening) between weeks 16-22. Third trimester (weeks 28-40) involves glucose tolerance testing at weeks 24-28, Group B strep screening at weeks 35-37, and weekly appointments from week 36. Full term begins at week 37, and most IVF pregnancies are managed similarly to natural pregnancies after the first trimester.
Does a frozen embryo transfer (FET) affect the due date calculation?
No, the due date calculation is identical for fresh and frozen transfers. The formula depends only on the transfer date and the embryo's developmental stage (Day 3, 5, or 6), not on whether the embryo was cryopreserved. A Day 5 blastocyst transferred fresh and a Day 5 blastocyst thawed and transferred on the same date will have the same due date. The freezing and thawing process pauses embryo development but does not alter the age assigned to the embryo at the time of transfer.
How long should I continue progesterone after an IVF transfer?
Most fertility clinics prescribe progesterone supplementation from the time of embryo transfer through weeks 8-12 of pregnancy. Progesterone supports the uterine lining and is essential for early pregnancy maintenance. In natural conception, the corpus luteum produces progesterone, but IVF patients (especially FET cycles) may not have adequate corpus luteum function. Your fertility specialist will monitor your progesterone levels and typically discontinue supplementation once the placenta takes over hormone production, usually by week 10-12. Never stop progesterone without your doctor's guidance, as premature discontinuation can risk miscarriage.