Pregnancy Week 40

Evidence-informed content. Review status is maintained by the editorial team.

Week 40 sits within the third trimester. You have reached the estimated due week, which is an estimate rather than an expiry date. This guide explains what may be happening now, what can vary, and which concerns deserve prompt professional advice.

What is happening at pregnancy week 40

Labour may begin spontaneously, but it is common for pregnancy to continue beyond the estimated due date, especially when dating is uncertain. Gestational age is counted from the first day of the last menstrual period, so early numbered weeks include time before conception. Dating may later be adjusted using clinical information and ultrasound.

Baby development

The fetus continues brain and lung maturation and maintains fat stores while awaiting birth.

Approximate size and growth

Average term newborn size varies widely; estimates from examination or ultrasound have a margin of error and cannot predict an individual birth weight precisely.

Changes you may notice

Contractions, pelvic pressure and sleep disruption may be present, or there may be no clear sign that labour is near. Some people notice several changes at once, while others feel little different. The presence or absence of a symptom cannot on its own confirm how a pregnancy is progressing.

Common symptoms

• Pelvic pressure and backache
• Irregular or regular contractions
• Mucus discharge and fatigue

These experiences are possibilities, not a checklist. Symptoms can be mild, strong, intermittent or absent at week 40, and a different pattern does not automatically mean that anything is wrong.

Emotional wellbeing

Reaching the due date without labour can feel disappointing or stressful. The date is a midpoint estimate within a broader normal window. A short daily check-in can help: notice what feels manageable, identify one source of support, and write down a concern instead of carrying it alone.

If worry is persistent, interferes with sleep or daily life, or makes it hard to cope, tell your midwife, doctor or another trusted healthcare professional. Emotional health deserves the same attention as physical health.

Nutrition and hydration

Continue ordinary balanced food and hydration, and avoid castor oil, herbs or other unreviewed methods intended to trigger labour. Sip fluids regularly and use urine colour and thirst as everyday prompts, while following any fluid advice given for a medical condition.

Aim for regular meals built around vegetables and fruit, wholegrain or other fibre-rich foods, protein foods and suitable dairy or alternatives. Follow local advice on prenatal supplements and foods to avoid; individual needs differ, especially with allergies, diabetes, anaemia or severe nausea.

Safe movement and daily comfort

Move for comfort and circulation, not as a test of effort or a guaranteed way to start labour. Choose an intensity at which you can still speak comfortably, include rest, and adapt for heat, balance changes or pelvic discomfort.

For an uncomplicated pregnancy, comfortable everyday activity is often encouraged. Stop and seek advice if movement causes pain, bleeding, dizziness, chest symptoms, fluid loss or contractions. A clinician can tailor advice for complications or a previously inactive routine.

Appointments and screening

Discuss monitoring, membrane sweep and induction options, including benefits, risks, timing and alternatives, based on local guidance and individual factors.

Exact schedules and tests vary by country, pregnancy history and care plan. Keep a note of new symptoms, medicines and questions so your appointment can focus on what matters to you.

Warning signs and when to seek care

Trust a strong sense that something is wrong: maternity services would rather assess a concern than have you delay because it does not match a list.

• Contact your maternity service promptly for vaginal bleeding, suspected fluid loss, severe or persistent abdominal pain, a severe headache, vision changes, sudden swelling, fever, breathing difficulty, chest pain or feeling acutely unwell.
• Once you have established a usual pattern of movement, seek maternity advice promptly if your baby is moving less than usual or the pattern changes. Do not wait for the next day.
• Use emergency services for collapse, severe breathing difficulty, heavy bleeding, a seizure or another immediately life-threatening concern.

Practical preparation for this week

Confirm the next appointment and exactly whom to call for reduced movement, fluid loss, bleeding or contractions.

• Review the post-dates plan
• Keep monitoring the usual movement pattern
• Protect rest and reduce social pressure

Frequently asked questions

Is it dangerous to go past 40 weeks?

Risk changes gradually rather than suddenly on the due date. Your team will discuss monitoring and timing of birth based on gestation and individual circumstances.

Can I decline or delay induction?

You are entitled to informed discussion of benefits, risks and alternatives. Decisions should be made with your maternity team and reviewed if circumstances change.

Should I compare my pregnancy with someone else at week 40?

No two pregnancies follow an identical pattern. Dating can vary, symptoms are influenced by many factors, and growth is assessed over time rather than from a single comparison. Bring personal concerns to your maternity team.

Week 40 in brief

Week 40 is the estimated due week, not a deadline. Continue movement awareness and make a clear, shared plan for monitoring and birth timing.

References

The following authoritative resources support editorial and professional review. Guidance should be checked for currency and local applicability before publication.

• nhs.uk
• womenshealth.gov
• cdc.gov