How to Calculate Your IVF Due Date
Complete guide covering the formulas, methodology, and step-by-step instructions for calculating your due date after IVF.
IVF Due Date Calculator
Calculate your pregnancy due date based on your embryo transfer date. This free IVF due date calculator works for both fresh and frozen embryo transfers (FET) with day 3, day 5, or day 6 embryos. Get instant results including your estimated due date, current gestational age, trimester, pregnancy progress, and a complete timeline of milestones from beta HCG test through delivery.
Key Facts About IVF Due Dates
- Day 5 transfers (most common): Add 261 days to your transfer date for your due date
- At transfer, you're already ~2.5 weeks pregnant by medical dating standards
- Fresh vs. frozen doesn't affect the calculation—only embryo age matters
- IVF dating is more accurate than natural conception dating because fertilization date is known
- ~5% of babies arrive on their exact due date; most come within 2 weeks
- All calculations happen in your browser—we never see or store your dates
The date your embryo was transferred
Your Estimated Due Date
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Pregnancy Progress
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Gestational Age
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Trimester
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Until Due Date
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Since Transfer
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Your Input Summary
Your Complete Results
Tips for Your IVF Pregnancy
Save Your LMP Date
Use your theoretical LMP when filling out medical intake forms at new healthcare providers.
Schedule Key Appointments
Book your anatomy scan (18-22 weeks) and glucose test (24-28 weeks) in advance.
Track Movement After 20 Weeks
Once you feel regular kicks, monitor daily and report any significant decrease.
Communicate Your IVF Dating
Tell your OB your transfer-based date is precise—it's more accurate than LMP dating.
Your Pregnancy Milestones
View calculation formula used
Medical Disclaimer
This calculator provides estimates based on standard IVF dating formulas. Your actual due date may differ based on ultrasound measurements. Always consult your fertility clinic or OB-GYN for official dating and medical guidance.
Due Date
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Current Week
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Week-by-Week Pregnancy Timeline
Green = completed weeks | Purple = current week | Gray = upcoming weeks
Medical Disclaimer
This timeline is for informational purposes only. Individual pregnancies may vary. Consult your healthcare provider for personalized guidance.
Leave empty for today
Gestational Age
-- weeks, -- days
Total Days
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Since Transfer
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Until Due
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Trimester
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Due Date
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Using This Information
Your gestational age is how healthcare providers measure pregnancy progress. Use this when:
- Filling out medical forms that ask for gestational age
- Scheduling time-sensitive appointments or tests
- Answering "how far along are you?"
- Tracking development milestones week by week
How IVF Due Date Calculation Works
IVF due dates are calculated differently than natural conception pregnancies. Since we know the exact day of fertilization (egg retrieval) and embryo transfer, the calculation is more precise.
The Formula
For IVF pregnancies, gestational age begins 14 days before egg retrieval (to match natural cycle dating). This means at the time of a day 5 blastocyst transfer, you are already 2 weeks and 5 days pregnant (19 days gestational age).
| Embryo Age | Gestational Age at Transfer | Days to Add for Due Date |
|---|---|---|
| Day 3 | 2 weeks, 3 days (17 days) | 263 days |
| Day 5 | 2 weeks, 5 days (19 days) | 261 days |
| Day 6 | 2 weeks, 6 days (20 days) | 260 days |
The most common transfer is a day 5 blastocyst. To calculate your due date: Transfer Date + 261 days = Estimated Due Date.
How to Use This Calculator
This calculator offers three tools to help you track your IVF pregnancy. Here's how to use each one effectively.
Due Date Calculator (Main Tab)
This is the primary tool for calculating your estimated due date and viewing pregnancy milestones.
- Enter your transfer date: Select the exact date your embryo was transferred to your uterus. This should be on your clinic paperwork or discharge instructions.
- Select embryo age: Choose whether your embryo was a Day 3 (cleavage stage), Day 5 (blastocyst), or Day 6 embryo. If unsure, Day 5 is most common for modern IVF cycles.
- Choose transfer type: Indicate fresh or frozen (FET). This doesn't affect the calculation but helps you keep records.
- Click "Calculate Due Date": View your results including due date, current gestational age, trimester, and a timeline of key milestones.
Timeline Tab
Visualize your entire pregnancy journey week by week.
- Enter transfer date and embryo age: Same as the main calculator.
- Click "Generate Timeline": See all 40 weeks displayed by trimester, with your current week highlighted in purple.
- Track your progress: Completed weeks show in green, upcoming weeks in gray.
Gestational Age Calculator Tab
Calculate your exact gestational age for any specific date—past, present, or future.
- Enter transfer date: Your embryo transfer date.
- Enter target date (optional): The date you want to calculate for. Leave blank for today's date.
- Select embryo age: Day 3, 5, or 6.
- View results: See exact weeks and days, total gestational days, trimester, and days until due.
Tips for Accurate Results
- Use your actual transfer date: Not your retrieval date or the day you started medications.
- Confirm embryo age with your clinic: Day 5 blastocysts are most common, but verify your specific case.
- Remember dates are estimates: Only about 5% of babies arrive on their exact due date.
Common Mistakes to Avoid
- Using retrieval date instead of transfer date: The transfer date is typically 3-6 days after egg retrieval.
- Confusing embryo day with calendar days: "Day 5" refers to the embryo's age, not how many days after your period.
- Expecting exact accuracy: Due dates are estimates. Most full-term deliveries occur within 2 weeks of the calculated date.
Pro Tip
Take a photo of your clinic discharge paperwork showing your transfer date and embryo details. You'll reference these dates many times throughout your pregnancy, especially when filling out forms at new healthcare providers.
Real-World Examples
Here are examples showing how different people use this calculator. These illustrate typical scenarios and demonstrate how to interpret results.
Example 1: First-Time IVF Patient with Day 5 Blastocyst
Maria, a 34-year-old first-time IVF patient, had her day 5 blastocyst transfer on March 15, 2026. She wants to know her due date and current gestational age.
- Input: Transfer Date: March 15, 2026 | Embryo Age: Day 5
- Due Date Result: December 1, 2026 (March 15 + 261 days)
- Gestational Age at Transfer: 2 weeks, 5 days (19 days)
- If checking on April 15: 7 weeks, 0 days gestational age (31 days after transfer + 19 days = 50 days = 7 weeks)
Maria can use this date for scheduling her first ultrasound around week 6-7 and planning her maternity leave.
Example 2: Frozen Embryo Transfer (FET) with Day 6 Embryo
James and Lisa completed a frozen embryo transfer on January 10, 2026, using a day 6 blastocyst from their previous cycle.
- Input: Transfer Date: January 10, 2026 | Embryo Age: Day 6 | Type: Frozen
- Due Date Result: September 27, 2026 (January 10 + 260 days)
- Gestational Age at Transfer: 2 weeks, 6 days (20 days)
- LMP for medical forms: December 21, 2025 (January 10 minus 20 days)
The FET vs. fresh distinction doesn't change the calculation—what matters is the embryo was Day 6 at transfer.
Example 3: Day 3 Cleavage Stage Transfer
Sarah had a day 3 embryo transfer on February 20, 2026. Her clinic recommended a cleavage-stage transfer for her specific situation.
- Input: Transfer Date: February 20, 2026 | Embryo Age: Day 3
- Due Date Result: November 10, 2026 (February 20 + 263 days)
- Gestational Age at Transfer: 2 weeks, 3 days (17 days)
- Beta HCG Test: Approximately March 1, 2026 (9 days post-transfer)
Note that day 3 transfers add 263 days (2 more than day 5) because the embryo is 2 days younger at transfer.
Example 4: Calculating Gestational Age for an Upcoming Appointment
David and Anna had their transfer on April 5, 2026 (day 5 blastocyst). They have an anatomy scan scheduled for August 20, 2026, and want to know their gestational age on that date.
- Input: Transfer Date: April 5, 2026 | Target Date: August 20, 2026 | Embryo Age: Day 5
- Days since transfer: 137 days
- Gestational Age on August 20: 22 weeks, 2 days (137 + 19 = 156 days ÷ 7 = 22 weeks, 2 days)
- Trimester: Second trimester
This confirms their anatomy scan is appropriately scheduled in the typical 18-22 week window.
Example 5: Healthcare Provider Quick Reference
Dr. Chen needs to quickly calculate gestational age for a new OB patient who transferred on May 1, 2026 (day 5) and is being seen on June 15, 2026.
- Input: Transfer Date: May 1, 2026 | Check Date: June 15, 2026 | Embryo Age: Day 5
- Days since transfer: 45 days
- Gestational Age: 9 weeks, 1 day (45 + 19 = 64 days = 9 weeks, 1 day)
- Due Date: January 17, 2027
This helps the provider confirm dating and schedule appropriate prenatal care.
Example 6: Planning Maternity Leave
Jennifer, a marketing manager, had her transfer on June 10, 2026 (day 5). She wants to plan her maternity leave and know when she'll reach full term.
- Input: Transfer Date: June 10, 2026 | Embryo Age: Day 5
- Due Date: February 26, 2027
- Full Term (37 weeks): February 5, 2027
- Third Trimester Starts (28 weeks): December 3, 2026
Jennifer can use these milestones to plan her work transition and maternity leave start date.
Example 7: Donor Egg Recipient
Patricia, 42, used donor eggs and had a day 5 blastocyst transferred on July 25, 2026.
- Input: Transfer Date: July 25, 2026 | Embryo Age: Day 5
- Due Date: April 12, 2027
- Gestational Age at Transfer: 2 weeks, 5 days
- First Ultrasound (6 weeks): Around August 19, 2026
The calculation works the same regardless of whether the eggs were from the patient or a donor—transfer date and embryo age are what matter.
When to Use This Calculator
This calculator is designed for specific situations in the IVF pregnancy journey. Here's when it's most helpful:
Ideal Situations
- Right after a positive pregnancy test: Calculate your due date and start tracking milestones immediately after your beta HCG confirms pregnancy.
- Filling out medical intake forms: Many forms ask for LMP or due date. Use the calculator to find your theoretical LMP for accurate dating.
- Scheduling prenatal appointments: Know your gestational age to schedule ultrasounds, anatomy scans, and other time-sensitive tests at the right weeks.
- Planning work and personal life: Estimate when you'll reach each trimester, full term, and your due date to plan maternity leave and life logistics.
- Preparing for conversations with your OB: When transitioning from fertility clinic to OB care, having accurate dates helps ensure continuity.
- Tracking pregnancy week by week: Use the timeline tab to visualize your progress and see what's coming.
- Answering "How far along are you?": Quickly calculate your current weeks and days to answer this common question accurately.
- Understanding viability milestones: Know when you'll reach significant points like viability (24 weeks) or full term (37 weeks).
Who Benefits Most
- IVF patients (fresh transfers) who know their exact transfer date
- FET patients (frozen embryo transfers) needing to calculate dates from their transfer
- Donor egg and embryo recipients tracking pregnancy from transfer
- Gestational carriers and intended parents monitoring pregnancy milestones
- Healthcare providers needing quick IVF dating reference
- Anyone preparing for IVF who wants to understand how dating works
Quick Reference Tables
These tables provide at-a-glance reference data for IVF pregnancy dating.
Pregnancy Milestones by Gestational Week
Key milestones tracked by this calculator, showing typical timing for IVF pregnancies:
| Milestone | Gestational Week | Days After Day 5 Transfer | Significance |
|---|---|---|---|
| Beta HCG Test | ~3-4 weeks | 9-14 days | First pregnancy confirmation blood test |
| First Ultrasound | 6 weeks | 23 days | Confirm intrauterine pregnancy, see gestational sac |
| Heartbeat Visible | 7 weeks | 30 days | Fetal cardiac activity detected |
| End of First Trimester | 13 weeks | 72 days | Reduced miscarriage risk, transition to OB care |
| Anatomy Scan | 18-22 weeks | 107-135 days | Detailed fetal anatomy evaluation |
| Viability | 24 weeks | 149 days | Significant survival chance if born prematurely |
| Third Trimester | 28 weeks | 177 days | Final stage of pregnancy begins |
| Full Term | 37 weeks | 240 days | Baby considered fully developed |
| Due Date | 40 weeks | 261 days | Estimated delivery date |
LMP Calculation Reference
To calculate your theoretical Last Menstrual Period (LMP) for medical forms:
| Embryo Age | Subtract from Transfer Date | Example (Transfer: Jan 15) |
|---|---|---|
| Day 3 | 17 days | LMP = December 29 |
| Day 5 | 19 days | LMP = December 27 |
| Day 6 | 20 days | LMP = December 26 |
Trimester Boundaries
| Trimester | Weeks | Gestational Days | Days After Day 5 Transfer |
|---|---|---|---|
| First Trimester | Weeks 1-12 | Days 1-84 | Transfer to day 65 |
| Second Trimester | Weeks 13-27 | Days 85-189 | Days 66-170 |
| Third Trimester | Weeks 28-40 | Days 190-280 | Days 171-261 |
Formula Reference
Understanding the exact formulas helps you verify calculations and understand the methodology.
Core Due Date Formula
Due Date = Transfer Date + Days to Add
Where Days to Add:
• Day 3 embryo: 263 days
• Day 5 embryo: 261 days
• Day 6 embryo: 260 days
Where Days to Add:
• Day 3 embryo: 263 days
• Day 5 embryo: 261 days
• Day 6 embryo: 260 days
Gestational Age Formula
Gestational Age (days) = Gestational Days at Transfer + Days Since Transfer
Gestational Days at Transfer:
• Day 3 embryo: 17 days (2 weeks, 3 days)
• Day 5 embryo: 19 days (2 weeks, 5 days)
• Day 6 embryo: 20 days (2 weeks, 6 days)
Weeks = Floor(Gestational Age ÷ 7)
Days = Gestational Age mod 7
Gestational Days at Transfer:
• Day 3 embryo: 17 days (2 weeks, 3 days)
• Day 5 embryo: 19 days (2 weeks, 5 days)
• Day 6 embryo: 20 days (2 weeks, 6 days)
Weeks = Floor(Gestational Age ÷ 7)
Days = Gestational Age mod 7
Worked Example: Day 5 Transfer on March 15, 2026
Step 1: Calculate Due Date
March 15, 2026 + 261 days = December 1, 2026
Step 2: Calculate Gestational Age on April 15, 2026
Days since transfer = 31 days
Gestational days at transfer = 19 days
Total gestational days = 31 + 19 = 50 days
Weeks = 50 ÷ 7 = 7 weeks, 1 day
Step 3: Calculate Theoretical LMP
March 15, 2026 - 19 days = February 24, 2026
Why These Numbers?
The formulas are based on standard obstetric convention:
- 280 days (40 weeks) = standard pregnancy duration from LMP
- 14 days = assumed time from LMP to ovulation/fertilization
- Embryo age = days since fertilization at transfer
- Gestational age at transfer = 14 + embryo age
- Days to add = 280 - gestational age at transfer = 280 - (14 + embryo age)
Understanding Your Results
Here's how to interpret the various outputs from this calculator.
Estimated Due Date (EDD)
Your due date represents 40 weeks of pregnancy from your theoretical LMP. Important context:
- Normal range: Full-term delivery typically occurs between 37-42 weeks
- Only ~5% of babies are born on their exact due date
- Most deliveries occur within 2 weeks before or after the EDD
- IVF dating is more precise than LMP-based dating for natural conception
Gestational Age
Expressed in weeks and days (e.g., "8 weeks, 3 days" or "8w3d"). This tells you:
- Your current pregnancy stage: Used for scheduling appropriate tests and monitoring
- Fetal development milestones: Different organs develop at specific gestational ages
- Medical terminology: Healthcare providers use gestational age for all pregnancy discussions
Trimester
Pregnancy is divided into three trimesters, each with distinct characteristics:
- First Trimester (Weeks 1-12): Highest risk period for miscarriage; major organ formation; morning sickness common
- Second Trimester (Weeks 13-27): Often called the "honeymoon" phase; anatomy scan; baby movements felt
- Third Trimester (Weeks 28-40): Rapid baby growth; preparation for delivery; more frequent monitoring
Pregnancy Progress Percentage
Shows how far through the 40-week pregnancy you are. At 20 weeks, you're 50% through; at 30 weeks, you're 75% through.
When Results May Differ from Your Doctor's
Your healthcare provider may give you a different due date if:
- Early ultrasound measurements differ significantly: If crown-rump length differs by more than 5-7 days from transfer-based dating, some providers adjust
- You're carrying multiples: Twin pregnancies often deliver earlier than singletons
- There are medical factors: Certain conditions may change expected delivery timing
For IVF pregnancies, most clinics prefer the transfer-based date because it's the most accurate method available.
IVF Dating vs. Natural Conception Dating
Understanding how IVF pregnancy dating compares to natural conception helps you communicate with healthcare providers.
| Aspect | IVF/FET Pregnancy | Natural Conception |
|---|---|---|
| Dating Method | Transfer date + embryo age | Last menstrual period (LMP) |
| Fertilization Date | Known exactly (retrieval date) | Estimated (assumed day 14) |
| Accuracy | Very high (±0-1 days) | Variable (±1-2 weeks) |
| LMP | Calculated backward from transfer | Actual first day of last period |
| Ultrasound Adjustment | Rarely needed | Often adjusted based on first ultrasound |
| Ovulation Timing | Not relevant (embryo created in lab) | Assumed day 14, but varies widely |
Because IVF dating is so precise, most fertility clinics and OB practices consider the transfer-based date definitive unless ultrasound measurements differ dramatically.
Did You Know?
The term "blastocyst" (day 5 embryo) comes from the Greek words "blastos" (sprout) and "kystis" (bladder), describing the hollow ball structure that forms when the embryo is ready for implantation. At this stage, the embryo has 70-100 cells and has differentiated into cells that will form the placenta and cells that will become the baby.
IVF by the Numbers
Understanding the broader context of IVF helps put your journey into perspective. Here are key statistics about IVF success rates, pregnancy outcomes, and delivery timing.
Global IVF Statistics
12M+
IVF Babies Born
Worldwide since 1978
500K+
Annual IVF Cycles
In the United States
2.4%
Of US Births
Conceived via IVF
~55%
Avg. Live Birth Rate
Per transfer (under 35)
IVF Live Birth Rates by Age
Success rates vary significantly with age. The following chart shows approximate live birth rates per embryo transfer based on CDC data:
Source: CDC National ART Surveillance System. Rates represent live births per embryo transfer cycle.
When Do IVF Babies Actually Arrive?
Only about 5% of babies are born on their exact due date. Here's the distribution of delivery timing for singleton IVF pregnancies:
Fresh vs. Frozen Transfer Trends
The IVF landscape has shifted dramatically toward frozen embryo transfers in recent years:
The trend toward frozen embryo transfers (FET) has accelerated due to advances in cryopreservation, the adoption of preimplantation genetic testing (PGT), and evidence suggesting comparable or improved outcomes with frozen cycles.
| Year | Fresh Transfer % | Frozen Transfer % | Total US Cycles |
|---|---|---|---|
| 2014 | 57% | 43% | 208,604 |
| 2016 | 47% | 53% | 263,577 |
| 2018 | 38% | 62% | 306,197 |
| 2020 | 31% | 69% | 326,468 |
| 2022 | 27% | 73% | 413,776 |
| 2024 (est.) | 25% | 75% | ~500,000 |
Embryo Development: From Retrieval to Transfer
Understanding the stages of embryo development helps clarify why "embryo day" matters for due date calculations.
| Day | Stage | Cell Count | Key Development | Transfer? |
|---|---|---|---|---|
| Day 0 | Fertilization | 1 cell (zygote) | Sperm penetrates egg; DNA combines | No |
| Day 1 | Pronuclear stage | 1 cell (2PN) | Two pronuclei visible; fertilization confirmed | Rare |
| Day 2 | Cleavage | 2-4 cells | First cell divisions begin | Rare |
| Day 3 | Cleavage | 6-10 cells | Cells dividing; genome activation | Yes |
| Day 4 | Morula | 16-32 cells | Cells compact into a tight ball | Rare |
| Day 5 | Blastocyst | 70-100 cells | Fluid-filled cavity forms; inner cell mass + trophectoderm differentiate | Yes (most common) |
| Day 6 | Expanded blastocyst | 100-150 cells | Blastocyst expands further; hatching may begin | Yes |
| Day 7 | Hatching blastocyst | 150+ cells | Embryo hatches from zona pellucida | Rare |
Why Day 5 Transfers Are Most Common
~80%
Day 5 Transfers
Of all IVF transfers
50-60%
Implantation Rate
Day 5 blastocysts
25-40%
Implantation Rate
Day 3 cleavage stage
1
Embryo Transferred
Standard for blastocysts
Day 5 blastocyst transfers have become standard practice because extended culture to day 5 allows embryologists to identify the most viable embryos. At the blastocyst stage, the embryo has undergone significant genome activation and differentiation, providing better selection criteria. This also allows for single embryo transfer (SET), reducing the risk of multiple pregnancies while maintaining high success rates.
Fetal Size by Gestational Week
Track your baby's growth throughout pregnancy. These measurements represent averages and individual variation is normal.
| Week | Length (CRL/CHL) | Weight | Size Comparison | Key Development |
|---|---|---|---|---|
| 6 | 2-4 mm | <1 g | Lentil | Heart begins beating; neural tube forming |
| 8 | 1.6 cm | 1 g | Raspberry | All major organs forming; fingers emerging |
| 10 | 3.1 cm | 4 g | Kumquat | Vital organs functioning; tooth buds forming |
| 12 | 5.4 cm | 14 g | Lime | Reflexes developing; vocal cords forming |
| 16 | 11.6 cm | 100 g | Avocado | Sex determinable; hearing developing |
| 20 | 16.4 cm | 300 g | Banana | Movements felt; halfway milestone |
| 24 | 30 cm | 600 g | Ear of corn | Viability milestone; lungs developing surfactant |
| 28 | 37.6 cm | 1,000 g | Eggplant | Eyes can open; brain developing rapidly |
| 32 | 42.4 cm | 1,700 g | Squash | Practicing breathing; gaining fat reserves |
| 36 | 47.4 cm | 2,600 g | Romaine lettuce | Lungs nearly mature; head-down position common |
| 37 | 48.6 cm | 2,900 g | Winter melon | Full term; continued brain growth |
| 40 | 51.2 cm | 3,500 g | Watermelon | Due date; fully developed and ready for birth |
CRL = Crown-Rump Length (used through ~20 weeks). CHL = Crown-Heel Length (used after ~20 weeks). Weights and measurements are population averages.
Growth Visualization by Trimester
Prenatal Testing Schedule for IVF Pregnancies
IVF pregnancies follow a specific testing schedule. Some tests may differ from natural conception pregnancies, particularly in early pregnancy when monitoring is typically more frequent.
| Test / Screening | Gestational Week | Purpose | IVF-Specific Notes |
|---|---|---|---|
| Beta HCG (1st draw) | 4-5 weeks | Confirm pregnancy; measure hormone levels | Typically 9-14 days post-transfer; repeat in 48-72 hours |
| Beta HCG (2nd draw) | 4-5 weeks | Confirm HCG is rising appropriately | Should roughly double every 48-72 hours |
| Progesterone check | 4-8 weeks | Ensure adequate hormone support | IVF patients often on supplemental progesterone |
| First ultrasound | 6-7 weeks | Confirm intrauterine pregnancy; count gestational sacs | Especially important after multi-embryo transfer |
| Heartbeat confirmation | 7-8 weeks | Detect fetal cardiac activity | Heart rate should be 100-180 bpm |
| Graduation ultrasound | 8-10 weeks | Final check before transitioning to OB | Unique to IVF; "graduating" from fertility clinic |
| NIPT / Cell-free DNA | 10-13 weeks | Screen for chromosomal abnormalities | May be less needed if PGT-A was done |
| NT scan + bloodwork | 11-13 weeks | First trimester screening for Down syndrome | Nuchal translucency measurement |
| Anatomy scan | 18-22 weeks | Detailed fetal anatomy evaluation | Same as natural conception pregnancies |
| Glucose tolerance test | 24-28 weeks | Screen for gestational diabetes | IVF pregnancies may have slightly higher GDM risk |
| Tdap vaccine | 27-36 weeks | Protect newborn from whooping cough | Recommended for all pregnancies |
| Group B Strep test | 36-37 weeks | Screen for GBS bacteria | Determines if antibiotics needed during labor |
| NST / BPP | 36-40 weeks | Monitor fetal well-being | May start earlier or be more frequent for IVF |
IVF-Specific: Medication Weaning Schedule
Most IVF patients are on supplemental medications (progesterone, estrogen) during early pregnancy. Typical weaning schedules:
- Progesterone (PIO/suppositories): Usually continues through 8-12 weeks, then tapered over 1-2 weeks
- Estrogen (patches/pills): Usually discontinued at 8-10 weeks when placenta takes over
- Baby aspirin: May continue through 36 weeks if prescribed for preeclampsia prevention
Always follow your clinic's specific protocol for medication changes.
Factors That Affect IVF Pregnancy Outcomes
While due date calculation is straightforward, understanding the factors that influence IVF outcomes provides important context for your pregnancy journey.
| Factor | Higher Success | Lower Success |
|---|---|---|
| Maternal age | Under 35 | Over 40 (own eggs) |
| Embryo quality | Good-quality blastocyst (AA, AB) | Poor morphology grades |
| Embryo testing | PGT-A tested euploid | Untested or aneuploid |
| Transfer number | First or second transfer | Multiple failed transfers |
| Uterine lining | >7mm trilaminar pattern | <7mm or non-trilaminar |
| BMI | 18.5-30 | <18.5 or >35 |
| Smoking status | Non-smoker | Current smoker |
| Prior pregnancies | Previous live birth | Recurrent pregnancy loss |
| Underlying diagnosis | Tubal factor, male factor | Diminished ovarian reserve |
Embryo Grading System Explained
Embryo quality is graded differently at different stages. Here's how the most common blastocyst grading system works:
Expansion Grade (Number)
| Grade | Stage |
|---|---|
| 1 | Early blastocyst |
| 2 | Blastocyst |
| 3 | Full blastocyst |
| 4 | Expanded blastocyst |
| 5 | Hatching blastocyst |
| 6 | Hatched blastocyst |
Quality Grades (Letters)
| 1st Letter (ICM) | 2nd Letter (TE) |
|---|---|
| A = Many, tightly packed | A = Many, cohesive |
| B = Several, loosely grouped | B = Several, loose |
| C = Few cells | C = Few, large cells |
ICM = Inner Cell Mass (becomes baby). TE = Trophectoderm (becomes placenta). A "4AA" is an expanded blastocyst with excellent ICM and trophectoderm.
Pregnancy Weight Gain Guidelines
Recommended weight gain during pregnancy varies based on your pre-pregnancy BMI. These guidelines apply to IVF pregnancies just as they do to natural conceptions.
Singleton Pregnancy
| Pre-Pregnancy BMI | Category | Recommended Gain | Rate per Week (2nd/3rd Tri) |
|---|---|---|---|
| <18.5 | Underweight | 12.5-18 kg (28-40 lbs) | 0.44-0.58 kg/wk |
| 18.5-24.9 | Normal weight | 11.5-16 kg (25-35 lbs) | 0.35-0.50 kg/wk |
| 25.0-29.9 | Overweight | 7-11.5 kg (15-25 lbs) | 0.23-0.33 kg/wk |
| ≥30.0 | Obese | 5-9 kg (11-20 lbs) | 0.17-0.27 kg/wk |
Twin Pregnancy
| Pre-Pregnancy BMI | Recommended Gain |
|---|---|
| Normal weight (18.5-24.9) | 17-25 kg (37-54 lbs) |
| Overweight (25.0-29.9) | 14-23 kg (31-50 lbs) |
| Obese (≥30.0) | 11-19 kg (25-42 lbs) |
Where Does the Weight Go?
At full term (~40 weeks), here is how the typical weight gain is distributed:
Based on a total weight gain of ~13 kg (29 lbs) for normal-weight individuals. Source: IOM/ACOG guidelines.
IVF Cost Reference by Country
IVF costs vary dramatically by country. This table provides approximate ranges for a single IVF cycle, which may help with financial planning alongside your pregnancy timeline.
| Country | Avg. Cost per Cycle (USD) | Medication Included? | Public Funding Available? |
|---|---|---|---|
| United States | $12,000-$25,000 | Often separate ($3-7K) | Limited (varies by state) |
| United Kingdom | $5,000-$8,000 | Usually included | Yes (NHS: 1-3 cycles) |
| Australia | $6,000-$10,000 | Partially covered | Yes (Medicare rebate) |
| Canada | $8,000-$15,000 | Varies by province | Partial (Ontario, Quebec) |
| Spain | $4,500-$7,000 | Usually included | Yes (public system) |
| Czech Republic | $2,500-$4,500 | Usually included | Yes (up to age 39) |
| India | $2,000-$4,000 | Usually included | Limited |
| Japan | $3,000-$8,000 | Varies | Yes (national insurance) |
| Israel | Fully covered | Yes | Yes (up to 2 children) |
| Denmark | Fully covered | Yes | Yes (public: up to 3 cycles) |
Costs are approximate and subject to change. Additional procedures (PGT-A, ICSI, FET) may add $2,000-$6,000. Always verify with specific clinics.
In-Depth IVF Pregnancy Guides
Explore our comprehensive guides to learn more about IVF pregnancy dating, milestones, and what to expect.
Frozen Embryo Transfer (FET) Due Date
Everything you need to know about calculating due dates after a frozen embryo transfer, including FET-specific considerations.
IVF Pregnancy Week by Week
Detailed breakdown of what to expect each week of your IVF pregnancy, from transfer through delivery.
IVF Pregnancy Milestones Timeline
Track key dates and milestones throughout your IVF pregnancy journey, from beta test to due date.
How Accurate is Your IVF Due Date?
Understand the accuracy of IVF dating compared to natural conception and what factors might affect your due date.
IVF Twins Due Date Calculator
Special considerations for calculating due dates when expecting twins after IVF, including typical delivery timing.
Frequently Asked Questions
The final due date (40 weeks) is the same concept, but IVF dating is more accurate because we know the exact fertilization date. Natural conception dating often uses the last menstrual period (LMP), which assumes ovulation on day 14 – not always accurate. Learn more in our guide to IVF gestational age.
Medical dating counts pregnancy from the theoretical "last menstrual period" (LMP), which is 14 days before conception. Since a day 5 embryo is already 5 days old, your gestational age is 14 + 5 = 19 days (2 weeks, 5 days) at transfer. Our complete IVF due date guide explains this in detail.
No. What matters is the embryo age at transfer (day 3, 5, or 6). Whether the embryo was fresh or frozen doesn't change the due date calculation. Read our fresh vs. frozen transfer comparison for more details.
Early ultrasounds (6-9 weeks) are very accurate. If your ultrasound differs by more than 5-7 days, your doctor may adjust your due date. With IVF, most clinics stick with the transfer-based date since it's so precise. Learn more about IVF due date accuracy.
For a day 5 transfer: LMP = Transfer Date minus 19 days. For day 3: minus 17 days. For day 6: minus 20 days. This gives you the "theoretical LMP" to match your gestational dating.
Key milestones include: beta HCG test (9-14 days post-transfer), first ultrasound (6 weeks), heartbeat visible (7 weeks), end of first trimester (13 weeks), anatomy scan (18-22 weeks), viability (24 weeks), third trimester (28 weeks), and full term (37 weeks). See our IVF milestones timeline for details.
The calculation is the same, but twin pregnancies often deliver earlier—typically around 36-37 weeks rather than 40 weeks. Your healthcare provider will monitor you more closely and discuss delivery timing. Read our IVF twins due date guide for more information.
This calculator uses the same formulas fertility clinics use worldwide. For IVF pregnancies, transfer-based dating is considered the most accurate method available. However, always follow your healthcare provider's guidance if they recommend a different date based on ultrasound measurements or other clinical factors.
IUI (intrauterine insemination) pregnancies are dated differently since there's no embryo transfer. For IUI, the due date is typically calculated from the insemination date or trigger shot date. See our IUI due date guide for specific instructions.
You should discuss your due date with your healthcare provider at your first OB appointment, especially if early ultrasound measurements differ significantly from your transfer-based date, if you're carrying multiples, or if you have any risk factors that might affect delivery timing. This calculator is for informational purposes—always rely on your doctor for official medical guidance.
Master Your IVF Pregnancy Journey
Our comprehensive guides cover everything you need to know about IVF pregnancy dating, from calculating your due date to understanding each week of your pregnancy.
IVF Due Date Calculation Guide — Step-by-step instructions and formula explanations
FET Due Date Guide — Everything about frozen transfer dating
Week-by-Week Timeline — What to expect each week of pregnancy
Due Date Accuracy — Understanding how precise your date really is
Calculator last updated: January 2026 · Formulas verified against standard obstetric guidelines