Forty weeks is your official due date — but it’s worth knowing upfront that only about 5% of babies actually arrive on that exact day. If you’re at 40 weeks with no signs of labor yet, that’s completely normal. Here’s what’s happening for you and your baby, and what comes next if labor hasn’t started.
Your Baby at 40 Weeks
By 40 weeks, your baby is considered fully developed and ready for life outside the womb. Average size at this stage is around 7.5 pounds and about 20 inches long, though this varies quite a bit from baby to baby. Your baby will keep moving right up until — and during — labor, so continuing to track movement patterns still matters even this close to delivery.
Why So Few Babies Arrive on Their Due Date
A due date is an estimate based on a 280-day (40-week) average pregnancy length counted from the first day of your last menstrual period — not a deadline. In reality, a full-term pregnancy is considered anywhere from 37 to 42 weeks, and it’s entirely normal to go past 40 weeks, especially with a first pregnancy.
What Happens If You Go Past Your Due Date
If labor hasn’t started by 40 weeks, your provider will likely increase monitoring rather than jump straight to intervention. This typically includes:
Non-stress tests, which track your baby’s heart rate and movement
A biophysical profile, combining ultrasound with heart rate monitoring to check amniotic fluid levels, breathing movements, and overall wellbeing
Cervical checks, to see if your body is starting to prepare for labor
Pregnancy terminology beyond 40 weeks is specific:
Late term: 41 weeks 0 days – 41 weeks 6 days
Postterm: 42 weeks and beyond
The Induction Conversation
Research consistently shows that risks — including stillbirth — begin rising modestly around 41 weeks and increase more significantly after 42 weeks. Because of this, most providers will discuss induction if labor hasn’t started naturally by somewhere between 41 and 42 weeks, though the exact timing and approach vary by provider and by your individual risk factors. Some conditions — like gestational diabetes, preeclampsia, or concerns about amniotic fluid levels — may prompt an earlier conversation about induction regardless of your due date.
It’s worth knowing that induction itself carries some risks too, including changes in fetal heart rate and a higher likelihood of needing continuous monitoring during labor. This is a decision best made together with your provider, weighing your specific circumstances rather than a one-size-fits-all rule.
Common Symptoms at 40 Weeks Pregnant
Increased pelvic pressure
Stronger, more frequent Braxton Hicks contractions
Trouble sleeping
Nesting instinct — a sudden burst of energy to clean, organize, or prepare
Loss of the mucus plug, or increased vaginal discharge
Lower back pain
Emotional ups and downs — a mix of impatience, excitement, and anxiety is extremely common at this stage
Can You Naturally Induce Labor?
It’s a common question, but there’s no solid evidence that anything — walking, spicy food, sex, or herbal supplements — reliably starts labor. Herbal supplements in particular are best avoided, since they can carry risks for your baby. Labor generally starts on its own timeline, influenced by hormonal changes rather than anything you actively do.
When to Call Your Doctor
Contact your provider right away for a significant decrease in fetal movement, your water breaking, heavy vaginal bleeding, or contractions that are becoming regular and increasingly close together — these are all reasons to be seen or head to the hospital.
Tips for Week 40
Rest as much as possible — labor takes real physical energy
Keep doing daily kick counts
Stay in close contact with your provider about monitoring and next steps
Try to stay mentally flexible about timing; babies rarely follow a strict schedule
Lean on your support system for both practical help and reassurance
FAQ
How many babies are actually born on their due date?
Only about 5%. Most babies arrive within a week or two of the estimated due date, either before or after.
Is it dangerous to go past 40 weeks pregnant?
Not typically on its own. Risks rise modestly starting around 41 weeks and more significantly after 42 weeks, which is why increased monitoring — and eventually induction — becomes part of the conversation.
How big is a baby at 40 weeks pregnant?
On average, around 7.5 pounds and about 20 inches long, though healthy babies vary widely in size.
Can I do anything to naturally start labor?
There’s no reliable evidence that any activity — exercise, spicy food, sex — triggers labor. It’s best to avoid herbal supplements marketed for this purpose, as they can pose risks.
When will my doctor recommend induction if I go past my due date?
This varies by provider and individual risk factors, but many recommend discussing induction somewhere between 41 and 42 weeks if labor hasn’t started on its own, sometimes earlier if there are specific medical concerns.
