IVF Pregnancy Calculator — Week 26 (Day 3 & Day 5 Transfer)
You are 26 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.
IVF Pregnancy Calculator
Enter your egg retrieval date and select day-3 or day-5 transfer. EDD = retrieval + 266 days.
Baby at week 26
At 26 weeks gestational after IVF transfer: Eyelids open for the first time. Testes descend in males. Fetus recognises parents' voices.
Mother's body — what changes
Post-IVF at week 26, clinical picture: Third trimester approaches. Insomnia common. Backache from postural changes.
Nutrition & supplements
Add ~340 kcal/day above pre-pregnancy baseline. Prioritise iron (27 mg/day), calcium (1000 mg), omega-3 DHA (200–300 mg) and 71 g protein. Continue prenatal vitamin. 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
Continue 150 min/week. Avoid supine (flat-on-back) exercises after week 20 — they compress the vena cava. Swimming and prenatal Pilates are ideal now. After IVF avoid high-impact activity until confirmed viability at 8-week scan. Then follow standard trimester guidance.
Doctor visit checklist — week 26
- ✓Third trimester begins next week — pack hospital bag list
- ✓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 gush of fluid (early rupture of membranes)
- ⚠Absent fetal movement for 12+ hours after 24 weeks
- ⚠Severe headache + visual disturbance (preeclampsia)
Week 26 — Frequently asked questions
How accurate is the IVF Pregnancy Calculator at week 26?
The calculator uses standard gestational-age arithmetic (LMP + 280 days for standard; egg retrieval + 266 days for IVF day-5). Ultrasound crown-rump length between weeks 8–13 is more accurate (±5 days) than LMP — adjust EDD accordingly if the scan differs by more than 7 days.
What size is my baby at week 26?
Approximately the size of a scallion — length 35.6 cm and weight 760 g. These are median values from ASRM, SART and ESHRE references.
Which symptoms are normal in week 26?
Third trimester approaches. Insomnia common. Backache from postural changes. Every pregnancy is different — call your provider if anything on the warning-signs list appears.
Should I have an ultrasound at week 26?
Third trimester begins next week — pack hospital bag list. Routine scan windows are: dating (10–13w), anatomy (18–22w), growth (28–32w).
How much weight should I gain by week 26?
Approximately 7.8 kg cumulative if you started at a normal BMI (IOM guideline). Underweight mothers gain more; overweight mothers less.
Day 3 vs Day 5 transfer at week 26 — what's the difference?
Day-5 blastocyst transfer adds 5 days to embryo age; Day-3 transfer adds 3 days. Gestational age = transfer date + (14 − transfer day) days + weeks since transfer. Both converge on the same due date; the difference matters only in the first 2 weeks.
Should I continue progesterone at week 26?
Most REI clinics wean progesterone by week 12. Follow your clinic's exact taper — abrupt stop before placental takeover risks miscarriage.
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.