Pregnancy › Week by Week › Week 40
At 40 weeks your baby is about the size of a small pumpkin. This is your due date, and it helps to remember it is an estimate, not a deadline. Most babies arrive within a week or two on either side of it.
Size
A small pumpkin
head to heel
Length
20.2 in
about 51.2 cm
Weight
7.6 lb
about 3460 g
Your baby at 40 weeks
Fully grown and ready to be born, just continuing to add a little fat while the two of you wait.
Your baby is done developing and simply finishing up. Every organ is formed and working, the reflexes for feeding are ready, and the only real change from here is a bit more fat and a little more length.
Brain and lungs. These keep maturing right up to birth and continue after your baby arrives, which is part of why full term through 40 weeks is such a healthy place to be born.
Skin and nails. The skin is smooth and pink-white now, with most of the vernix and lanugo gone. Fingernails often reach past the fingertips, so your newborn may arrive with a tiny scratch or two.
Position and movement. Your baby is tucked low, usually head down, with very little room to move. You will feel firm rolls and pushes rather than big kicks, and those movements should still be regular. Keep counting them and call your provider the same day if the pattern drops.
How big is your baby at 40 weeks?
About 20.2 inches (51.2 cm) head to heel and roughly 7.6 pounds (3.5 kg).
Babies vary a lot in size at term, and the numbers here are averages, so a healthy baby can weigh quite a bit more or less. Your provider’s growth estimates are just that, estimates, and the exact size is not known until your baby is in your arms.
Your body at 40 weeks
Waiting, heavy, and impatient. All of it is normal, and so is going a little past your date.
Reaching your due date without a baby in your arms can feel strange and frustrating, especially with everyone asking. It helps to know that your due date was only ever an estimate of your 40-week mark, and that many first babies arrive after it. You may feel strong pelvic pressure, more Braxton Hicks, bloody show, loose stools, and bursts of nesting energy, all quiet signs the body is getting ready without a set timetable.
Keep resting when you can, stay hydrated, and keep counting your baby’s movements, that stays important right through to birth. When true labor starts, time your contractions and let our labor and birth guide walk you through what to expect and when to head in.
Past your due date: what happens next
Going a little overdue is common and usually fine. Here is how providers watch over the days just past 40 weeks.
A pregnancy is called late term from 41 weeks and postterm once it reaches 42 weeks. Most people who go past their date do so by only a few days, and the vast majority go into labor on their own before 42 weeks. Still, once you pass your due date, your provider keeps a closer eye on things, because the placenta and fluid are monitored more carefully as the weeks stretch on.
Monitoring. If you go past 40 weeks, your provider will usually schedule extra checks. A non-stress test tracks your baby’s heart rate and movements over about 20 to 30 minutes to confirm your baby is doing well, and an ultrasound may check the amniotic fluid level and the baby’s activity, often together called a biophysical profile. These are simple, comfortable checks that let everyone wait with more confidence.
Membrane sweep. Around or just past your due date, your provider may offer a membrane sweep, sometimes called stripping the membranes. During a cervical exam, they run a finger around the inside edge of the cervix to separate the membranes slightly from it, which can release hormones that help labor start. It can be uncomfortable and cause some spotting or cramping, and it does not always work, but for some people it nudges things along and may lower the chance of needing an induction.
Induction. If your baby has not arrived as 41 to 42 weeks approach, your provider will talk with you about an induction, which means starting labor with medication or other methods rather than waiting for it to begin on its own. Guidance from ACOG supports offering induction in the late-term window to lower the small risks that rise the further past term a pregnancy goes. The timing is a conversation between you and your provider, weighing your health, your baby’s monitoring, and your preferences. If induction is on the table for you, ask what the plan involves so you know what to expect.
What is normal, and when to call your provider
Waiting and practice contractions are normal now, but call your provider or go in for any of these:
- A clear drop in your baby’s movements, or a stretch without the usual pattern, call the same day
- A gush or a steady leak of fluid, which can mean your water has broken
- Any bright red vaginal bleeding, which is different from the pink-tinged mucus of bloody show
- A severe headache, vision changes, pain under your ribs, or sudden swelling of the face or hands, which can signal preeclampsia
- Regular, painful contractions that keep building are a sign of labor. See labor and birth and follow your provider’s when-to-come-in rule
- A fever over 100.4°F (38°C)
Your week 40 checklist
- Keep every appointment, this is when the extra monitoring past your date happens
- Ask your provider about a membrane sweep and their induction timeline if you go overdue
- Keep the hospital bag, car seat, and bassinet ready for the first nights home
- Set out your postpartum recovery comforts so they are waiting for you
- Keep counting your baby’s movements every day and call the same day for any drop
Appointments and tests around 40 weeks
Visits stay weekly or move closer together, with monitoring added if you go past your date.
Your provider checks your blood pressure, confirms the baby is head down, and asks about movements and any signs of labor. If you reach or pass your due date, expect the extra checks described above, a non-stress test and sometimes an ultrasound for fluid and activity, to confirm your baby is doing well while you wait. Your provider will also talk through their plan for the days ahead, including a possible membrane sweep and the timing of an induction if you approach 41 to 42 weeks. There is no single right answer here, only the plan that fits you and your baby, worked out together.
A few things worth having on hand now
A note for your partner
The overdue stretch can wear on everyone. Shield the person carrying from the constant any-news messages, keep the car and the bag ready, and stay reachable at all hours. If an induction gets scheduled, go to the appointments together and ask the questions, so you both walk in knowing the plan. Steady patience is the most useful thing you can offer now.
However your baby arrives
Reaching your due date is a milestone, whether your baby comes today or takes another week or two. Going a little past your date is common and usually completely fine, and your provider is watching closely. Very soon, in a way and on a day you cannot fully plan, you will meet the person you have been carrying all this time.
40 weeks pregnant, common questions
Is it bad to go past my due date?
Usually not. A due date is an estimate, and many babies, especially first ones, arrive after it. Providers keep a closer eye on things once you pass 40 weeks and talk with you about timing as 41 to 42 weeks approach, but going a few days over is common and generally fine.
What is a membrane sweep?
During a cervical exam, your provider runs a finger around the inside edge of the cervix to gently separate the membranes from it, which can release hormones that help labor start. It may cause spotting or cramping and does not always work, but for some people it nudges labor along and can lower the chance of an induction.
When is induction offered?
If your baby has not arrived as 41 to 42 weeks approach, your provider will usually discuss induction, which starts labor with medication or other methods. ACOG supports offering it in the late-term window to reduce the small risks that rise the further past term you go. The timing is a decision you make together based on your health and your baby’s monitoring.
What is a non-stress test?
It is a simple, comfortable check, usually 20 to 30 minutes, that tracks your baby’s heart rate and movements to confirm your baby is doing well. It is often used once you are past your due date, sometimes with an ultrasound of the amniotic fluid, so you can keep waiting with confidence.
Sources
- American College of Obstetricians and Gynecologists (ACOG), management of late-term and postterm pregnancy and induction of labor.
- Mayo Clinic, Overdue pregnancy: what to do when baby is late.
- MedlinePlus, National Library of Medicine (NIH), Postterm pregnancy and prenatal care.
Medical disclaimer: This page is for information and education only and is not a substitute for professional medical advice. Every pregnancy is different. Always follow the guidance of your doctor, midwife, or qualified provider, and contact them with any concerns.