At 40 weeks your baby is about 51.5 cm and 3.6 kg — roughly a small watermelon — and by every measure, fully ready. The due date has arrived, though it is worth remembering that only about 5% of babies are born on this exact day.
The short answer: baby is fully ready now, with a skull that stays flexible right up to birth to pass safely through the birth canal. The due date itself is only an estimate — most babies arrive within a couple of weeks either side of it, and pregnancy continuing to 42 weeks is considered entirely normal. For you, strong pressure in the perineum and more frequent contractions are common as the body finishes its final preparations.
Your baby this week
After this 40-week journey, baby is fully ready to meet you. The skull stays flexible right up until birth, allowing it to mould slightly and pass safely through the birth canal. Every major system — lungs, digestion, temperature regulation, reflexes — is prepared for independent life outside the womb.
It is worth remembering that the due date is a statistical estimate, not a deadline: it marks the middle of a normal range rather than a day baby is somehow expected to arrive on precisely.
Your body this week
Your body is fully ready too. You may feel strong pressure in the perineum and more frequent contractions as baby settles fully into position — the final physical preparations before labour begins in earnest. The single most useful thing right now is staying as calm as you can and trusting the process, however difficult that is to do while waiting.
If contractions do start, remember the breathing techniques you have been practising — deep, slow, deliberate breathing remains one of the most genuinely useful tools available once labour is underway.
Tests and appointments
Tests and scans around now: Past the due date, a membrane sweep and a plan for induction are usually discussed, with monitoring of the baby if the pregnancy continues.
Exact timing varies by country and by your own care plan — your doctor or midwife will confirm the schedule that applies to you.
If the due date passes without labour starting, this conversation about a membrane sweep and, if needed, induction planning is a normal and expected part of care from here — not a sign that anything has gone wrong.
✅ Worth doing this week
- Don't worry if the due date passes — pregnancy to 42 weeks is considered normal
- Practise your relaxation breathing — it remains your best tool once labour begins
- Keep counting movements daily until labour actually starts
- Ask about a membrane sweep and induction timing at your next appointment if you go past the date
- Rest and stay as calm as you can — the waiting is genuinely one of the hardest parts
When to call your doctor
Call the same day if: contractions become regular and increasingly strong, your water breaks, movement feels reduced or unusually quiet, or you notice bleeding. Also call for a severe headache with visual disturbance, sudden swelling of the face or hands, or a temperature above 38°C.
FAQ — 40 weeks pregnant
Is it normal to go past the due date?
Yes — the due date is an estimate based on averages, and only about 5% of babies are actually born on that exact day. Pregnancy continuing up to 42 weeks is considered entirely normal, and your care provider will monitor both you and baby closely with checks like CTG and ultrasound scans if the due date passes.
What happens if I go past 40 weeks?
Once the due date passes, most care providers discuss options like a membrane sweep — a simple procedure that can help encourage labour to start — and begin planning for induction if labour has not started by a certain point, usually with increased monitoring of baby in the meantime. This is a conversation to have with your care provider about what fits your specific situation, not a fixed timeline that applies the same way to everyone.
Why do I feel strong pressure in the perineum now?
As baby settles fully into the pelvis in preparation for birth, pressure on the perineum and pelvic floor can feel noticeably stronger than in previous weeks. This is a normal part of the body's final preparations, alongside more frequent tightenings, though the same red-flag rules still apply — regular, strengthening contractions or any of the other labour signs are what to act on.
How big is the baby at 40 weeks?
About 51.5 cm and 3.6 kg — roughly a small watermelon, though the range of normal birth weight is genuinely wide. The skull stays flexible right up to birth, allowing it to pass safely through the birth canal, and baby is, by every measure, ready to meet you.
Week 40 at a glance
At 40 weeks your baby is about 51.5 cm and 3.6 kg, fully ready to meet you, with a flexible skull built for a safe passage through the birth canal. For you, the due date is only an estimate — just 5% of babies arrive exactly on it, and pregnancy to 42 weeks is entirely normal, with monitoring and, if needed, induction planning discussed as the natural next step.
Inside Baby Novum: the contraction timer and symptom log are ready the moment things start, so the due date passing without labour becomes an ordinary wait rather than a source of worry.