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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.

Trimester 3 · Week 39 of 4098%
Baby size
mini watermelon
Length
50.7 cm
Weight
3290 g

Pregnancy Calculator

Enter the first day of your last menstrual period (LMP). EDD = LMP + 280 days.

Choose a valid date to see the estimated timeline.
EDD = first day of the last menstrual period + 280 days (40 weeks). Current gestational age is elapsed days divided by 7.

How to Use This Calculator

1. Enter the LMP 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 JanLMP+280 daysEstimated due date
Known clinical dateUltrasoundClinician datingConfirm or revise estimate

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

Medically reviewed

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.