Pregnancy Calculator — Week 39: Baby Size, Symptoms & Due Date
You are in week 39 of a standard singleton pregnancy. Below is a complete evidence-based snapshot — baby's growth, your body, nutrition, exercise, red flags and a doctor visit checklist for this exact week.
Pregnancy Calculator
Enter the first day of your last menstrual period (LMP). EDD = LMP + 280 days.
Baby at week 39
This week: Full term. All organs ready for outside life. Placenta continues supplying oxygen and antibodies.
Mother's body — what changes
In week 39 you may notice: Nesting instinct peaks. Contractions become regular. Watch for water breaking.
Nutrition & supplements
Add ~450 kcal/day. Increase iron and DHA — brain growth peaks now. Split meals into 5–6 small portions to control heartburn and stable glucose.
Safe exercise
Reduce intensity but keep moving. Pelvic floor + squats prepare for labour. Avoid contact sports, ski, horse-riding and hot yoga.
Doctor visit checklist — week 39
- ✓Full term — labour may start any day
- ✓Blood pressure + weight + urine dipstick at every visit
- ✓Fetal heart tones from week 10–12 (Doppler)
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
- ⚠Regular contractions before 37 weeks (preterm labour)
- ⚠Reduced fetal movement — fewer than 10 kicks in 2 hours
- ⚠Sudden swelling of face/hands + severe headache (preeclampsia)
- ⚠Bright red bleeding (placental abruption or previa)
Week 39 — Frequently asked questions
How accurate is the Pregnancy Calculator at week 39?
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 39?
Approximately the size of a mini watermelon — length 50.7 cm and weight 3290 g. These are median values from ACOG, NHS UK and Mayo Clinic references.
Which symptoms are normal in week 39?
Nesting instinct peaks. Contractions become regular. Watch for water breaking. Every pregnancy is different — call your provider if anything on the warning-signs list appears.
Should I have an ultrasound at week 39?
Full term — labour may start any day. Routine scan windows are: dating (10–13w), anatomy (18–22w), growth (28–32w).
How much weight should I gain by week 39?
Approximately 13.7 kg cumulative if you started at a normal BMI (IOM guideline). Underweight mothers gain more; overweight mothers less.
What is my EDD if today is week 39?
Your estimated due date is 1 week from today. Calculator adds (280 − 7 × 39) days to today's date.
Can I travel during week 39?
Most airlines restrict flying after week 36 (32 for twins). Carry your antenatal notes and check-in seat with legroom.
Content aligned with ACOG, NHS UK and Mayo Clinic. 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.