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IVF Pregnancy Calculator — Week 13 (Day 3 & Day 5 Transfer)

You are 13 weeks pregnant after IVF (gestational age counted from egg retrieval + 14 days for day-5 transfer, +12 days for day-3 transfer). Below is what your embryologist and REI clinic expect at this exact stage.

Trimester 1 · Week 13 of 4033%
Baby size
pea pod
Length
7.4 cm
Weight
23 g

IVF Pregnancy Calculator

Enter your egg retrieval date and select day-3 or day-5 transfer. EDD = retrieval + 266 days.

Choose a valid date to see the estimated timeline.
EDD = egg retrieval date + 266 days. Active transfer setting: day 5.

How to Use This Calculator

1. Enter the retrieval date

Use the labelled fields and units that match your situation.

2. Calculate instantly

The result, visual comparison, and working update as values change.

3. Discuss the estimate with your clinician

Check assumptions, then copy, print, or share the calculation.

Practical Examples & Use Cases

Starting dateMethodCalculationPlanning use
1 JanRetrieval+266 daysEstimated due date
Known clinical dateUltrasoundClinician datingConfirm or revise estimate

Baby at week 13

At 13 weeks gestational after IVF transfer: Fingerprints form. Placenta takes over hormone production from the corpus luteum. Vocal cords develop further.

Mother's body — what changes

Post-IVF at week 13, clinical picture: Second trimester begins. Many symptoms ease. Visible bump for second-time mothers.

Nutrition & supplements

Focus on folic acid 400–600 mcg/day (neural tube), iodine 150 mcg, and small frequent meals to counter nausea. No extra calories yet — normal maintenance intake is adequate. Post-IVF continue progesterone support and prenatal vitamin exactly as your REI prescribed. Do not add herbal supplements without clearance — many interact with luteal support.

Safe exercise

150 minutes/week of moderate activity — brisk walking, stationary cycling, prenatal yoga. Stop any exercise that leaves you unable to hold a conversation. After IVF avoid high-impact activity until confirmed viability at 8-week scan. Then follow standard trimester guidance.

Doctor visit checklist — week 13

  • ✓Second trimester begins — schedule anatomy scan for weeks 18–22
  • ✓Progesterone support review — continue until placenta takeover (week 10–12)
  • ✓Beta-hCG doubling every 48–72 hours until viability scan
  • ✓First IVF viability ultrasound at 6–7 weeks gestational

Warning signs — call your provider immediately

  • ⚠Heavy bleeding (soaking a pad in an hour)
  • ⚠Severe abdominal pain that does not ease
  • ⚠Fever above 38°C / 100.4°F
  • ⚠Sudden loss of pregnancy symptoms + spotting
  • ⚠Severe one-sided pain (ectopic pregnancy signal)

Week 13 — Frequently asked questions

Medically reviewed

Content aligned with ASRM, SART and ESHRE. Reviewed by Dr. Maria Rehman, MD (OB/GYN). This page is educational and does not replace personal medical advice — call your obstetrician for any concern.