Pregnancy Calculator — Week 42: Baby Size, Symptoms & Due Date
You are in week 42 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 42
This week: Post-term. Risk of placental insufficiency rises. Induction strongly recommended.
Mother's body — what changes
In week 42 you may notice: Induction of labour offered/recommended per ACOG guideline (do not exceed 42+0).
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 42
- ✓Induction of labour — post-term risk exceeds benefit of waiting
- ✓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 42 — Frequently asked questions
How accurate is the Pregnancy Calculator at week 42?
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 42?
Approximately the size of a large pumpkin — length 51.7 cm and weight 3680 g. These are median values from ACOG, NHS UK and Mayo Clinic references.
Which symptoms are normal in week 42?
Induction of labour offered/recommended per ACOG guideline (do not exceed 42+0). Every pregnancy is different — call your provider if anything on the warning-signs list appears.
Should I have an ultrasound at week 42?
Induction of labour — post-term risk exceeds benefit of waiting. Routine scan windows are: dating (10–13w), anatomy (18–22w), growth (28–32w).
How much weight should I gain by week 42?
Approximately 15.0 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 42?
Your estimated due date is -2 weeks from today. Calculator adds (280 − 7 × 42) days to today's date.
Can I travel during week 42?
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.