IVF Pregnancy Calculator — Week 20 (Day 3 & Day 5 Transfer)
You are 20 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 20
At 20 weeks gestational after IVF transfer: Halfway point. Fetus swallows amniotic fluid — practices digestion. Sex confirmed on anatomy scan.
Mother's body — what changes
Post-IVF at week 20, clinical picture: Fundus reaches the navel. Weight gain 4–6 kg by now is expected in singleton pregnancy.
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 20
- ✓Anatomy scan completed — save images and report
- ✓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 20 — Frequently asked questions
How accurate is the IVF Pregnancy Calculator at week 20?
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 20?
Approximately the size of a banana — length 25.6 cm and weight 300 g. These are median values from ASRM, SART and ESHRE references.
Which symptoms are normal in week 20?
Fundus reaches the navel. Weight gain 4–6 kg by now is expected in singleton pregnancy. Every pregnancy is different — call your provider if anything on the warning-signs list appears.
Should I have an ultrasound at week 20?
Anatomy scan completed — save images and report. Routine scan windows are: dating (10–13w), anatomy (18–22w), growth (28–32w).
How much weight should I gain by week 20?
Approximately 5.1 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 20 — 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 20?
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.