The due date is day 280 counted from the first day of your last period, which makes it sound precise. It is not. In a study that followed natural pregnancies from the day of ovulation, the length of a healthy pregnancy still varied by 37 days once preterm births were set aside. The date is the middle of a spread, and a baby who arrives four days after it is on time.
What changes after the due date is not the baby but the conversation. This guide walks through what is offered at 39, 40, 41 and 42 weeks, what a membrane sweep does and how well it works, the actual numbers behind the advice to induce at 41 weeks, what induction involves, and what to do with the days in between.
The short answer. Nothing happens on the due date itself. From 39 weeks you can be offered a membrane sweep; at 41 weeks induction is offered, because the small risk of stillbirth rises with each week after 40; if you would rather wait past 42, you should be offered extra monitoring at least twice a week. Meanwhile, keep counting your baby's movements and call the same day if they change.
Why Due Dates Slip
Three things push a due date around. The first is dating itself: a date set from your period assumes ovulation on day 14, which is why a first-trimester scan usually overrides it. Our due date calculator explains how the two are reconciled. The second is natural variation, which the 37-day spread above describes. The third is that "term" is a range: from 37 weeks to 42 weeks, and anywhere in it is a normal length of pregnancy.
A pregnancy is formally prolonged, or post-term, from 42 weeks and 0 days. Most maternity units act a week before that, and the rest of this guide explains why.
Week by Week After 40
| Week | What is usually offered | What you can ask |
|---|---|---|
| 39+0 | A membrane sweep can be offered at any appointment from here. | Whether they suggest one now or at 40. |
| 40+0 | A routine check: blood pressure, urine, bump measurement, movements. A sweep if you have not had one. | What happens if labour has not started by 41. |
| 41+0 | Induction is offered and, if you accept, booked. Another sweep while you wait. | Which method they would use, and how long it typically takes there. |
| 42+0 onwards | If you have declined induction: increased monitoring — at least twice-weekly heartbeat traces and an ultrasound check of the amniotic fluid. | What result would change the plan. |
Our appointment schedule covers what each of these visits checks in detail, and the week 40 page covers what is happening to the baby meanwhile.
The Numbers Behind 41 Weeks
The advice to induce at 41 weeks rests on two bodies of evidence, and it is worth seeing both, because the absolute numbers are small and the decision is genuinely yours.
A meta-analysis of cohort studies covering 15 million pregnancies found that the risk of stillbirth rose from 0.11 per 1,000 pregnancies at 37 weeks to 3.18 per 1,000 at 42 weeks. Between 40 and 41 weeks the relative rise was 64%, which in absolute terms meant one additional stillbirth for every 1,449 pregnancies that continued from 40 to 41 weeks.
A Cochrane review of 34 trials comparing a policy of induction at or beyond 37 weeks with waiting found fewer deaths around birth with induction (0.4 versus 3 per 1,000), fewer stillbirths, and probably fewer caesareans rather than more. To prevent one perinatal death, 544 women would need to be induced.
Read those two ways at once. The risk is real and it rises every week, which is why the offer is made. The risk is also small in absolute terms — one in several hundred to one in over a thousand — which is why declining and waiting with monitoring is a reasonable choice that guidance explicitly supports. What is not reasonable is waiting without monitoring.
The Membrane Sweep
A membrane sweep is done during a vaginal examination: the midwife or doctor puts a finger just inside the cervix and moves it in a circle to separate the membranes from the wall of the uterus. That releases prostaglandins, which can soften the cervix and start contractions. It is offered from 39 weeks and can be repeated.
A 2020 Cochrane review found that sweeping may increase the chance of labour starting on its own and may reduce the need for a formal induction, but rated the evidence as low-certainty. It is uncomfortable for a minute or so, and light spotting and irregular cramps afterwards are expected — they are not the sweep "working", and they are not labour. If you have a low-lying placenta or your waters have broken, a sweep is not done.
How Induction Works
1. Ripening the cervix
If the cervix is closed and firm, the first step is a prostaglandin pessary, gel or tablet placed in the vagina, or a balloon catheter that applies gentle pressure from inside. Either can take many hours, and some units let you go home during this stage.
2. Breaking the waters
Once the cervix has opened enough, the membranes are broken with a small hook during an examination. Labour often follows on its own from here. If you were already contracting, this may be the only step needed.
3. The oxytocin drip
If contractions do not establish, a synthetic oxytocin drip is started and adjusted until they do. Contractions from a drip build faster than natural ones, the baby's heartbeat is monitored continuously, and this is the stage women describe as more intense.
The NHS is straightforward that induced labour is usually more painful than labour that starts on its own and that an assisted birth is more likely. All the usual pain relief is available, including an epidural, and it is worth writing your preferences into your birth plan before the day rather than deciding under a drip.
Natural Methods, Honestly
What the evidence says
- Nipple stimulation — the one folk method with a positive signal in trials. Ask first if your pregnancy is high-risk.
- Walking, sex, a warm bath — harmless, pleasant, unproven.
- Curry, pineapple, dates — unproven; fine to eat if you fancy them.
- Raspberry-leaf tea — no good evidence it starts labour; see our raspberry-leaf tea page before drinking it in quantity.
- Castor oil — causes vomiting and diarrhoea and is not recommended.
- Anything bought online to "induce" — no.
What to Do With the Waiting
The days after a due date are their own kind of hard: everyone is texting, you are enormous, and every twinge is interrogated. Three things are worth the effort. Count movements every day — our guide to kick counts covers how — because a change in the pattern is the single most important sign at this stage and needs a same-day call. Learn what real labour looks like, in our guide to the signs of labour, so that you are not second-guessing Braxton Hicks at 3am. And finish the bag, so the call, when it comes, is the only thing you have to do.
When to Call
Call your maternity unit the same day, at any point after 40 weeks, if: your baby's movements change, slow down or stop; your waters break, especially if the fluid is green, brown or bloodstained; you have any bleeding; you have a severe headache, visual disturbance or sudden swelling of the face and hands; or you have itching without a rash, particularly on the palms and soles.
Go in when: contractions are about five minutes apart, lasting a minute, for an hour — the 5-1-1 rule — or sooner if your unit told you to, you live far away, or this is not your first baby.
At a Glance
A due date is the middle of a five-week spread, and term runs to 42 weeks. A membrane sweep is offered from 39 weeks and may help labour start on its own. Induction is offered at 41 weeks because the stillbirth risk rises with each week — from 0.11 per 1,000 at 37 weeks to 3.18 per 1,000 at 42 — but the absolute risk stays small, so waiting with at least twice-weekly monitoring is a supported choice too. Induction ripens the cervix, breaks the waters and, if needed, adds an oxytocin drip; it is usually more painful than spontaneous labour but does not raise the caesarean rate. Whatever you decide, count movements daily and call the same day if they change.
Inside Baby Novum. The due date is worked out from your last period, or you enter the due date your scan gave you and the app derives the rest, and the contraction timer records every contraction with its length and interval, sounding the 5-1-1 alert when the pattern means it is time to go. The kick counter keeps its daily reminder running past 40 weeks, and the hospital bag checklist has a reminder of its own.
Next: Signs of Labour → · Water Breaking → · Kick Counts →
Frequently Asked Questions
What does overdue actually mean?
Term runs from 37 weeks to 42 weeks, so a baby born at 40 weeks and 5 days is not late. A pregnancy is formally prolonged or post-term from 42 weeks and 0 days. In practice most units discuss induction at 41 weeks, because the small risk of stillbirth rises with each week after 40.
How many babies are born on their due date?
Only a small minority. In a carefully dated study of natural pregnancies, where the day of ovulation was known, the length of a healthy pregnancy varied by 37 days even after preterm births were excluded. The due date is the middle of a spread, not a deadline, and most births fall within the two weeks either side of it.
Why is induction offered at 41 weeks rather than 42?
Because the stillbirth risk climbs week by week at the end of pregnancy. A meta-analysis of 15 million pregnancies found it rose from 0.11 per 1,000 at 37 weeks to 3.18 per 1,000 at 42, with a 64% relative rise between 40 and 41 weeks. Those are small absolute numbers, which is why the offer is at 41 rather than 40, and why declining is a reasonable choice too.
Can I decline induction?
Yes. It is an offer, not an instruction. If you choose to wait past 42 weeks, NICE guidance says you should be offered increased monitoring — at least twice-weekly heartbeat traces and an ultrasound check of the amniotic fluid. Ask what your unit will do and what would change the plan.
What is a membrane sweep and does it hurt?
During a vaginal examination the midwife or doctor sweeps a finger around the inside of the cervix to separate the membranes from it, which releases hormones that can start labour. It is offered from 39 weeks. It is uncomfortable rather than painful, and light spotting and irregular cramps afterwards are normal. It is not an induction.
Does a membrane sweep work?
It may. A 2020 Cochrane review found that sweeping may increase the chance of labour starting on its own and may reduce the need for a formal induction, but rated the evidence low-certainty. It can be repeated if labour does not start. Whether the timing and number of sweeps matter is still an open question.
Do curry, pineapple, walking or raspberry-leaf tea bring on labour?
There is no good evidence for any of them, and no harm in most. Nipple stimulation is the one folk method that has shown a signal in trials. Castor oil is the exception to "no harm": it causes vomiting and diarrhoea and is not recommended. Ask before trying anything if your pregnancy is high-risk.
Is induced labour more painful than natural labour?
The NHS says it usually is, and that assisted birth is more likely. Against that, the Cochrane review of induction at or beyond term found a policy of induction probably means fewer caesareans overall, not more. All the usual pain relief, including an epidural, is available in an induced labour.
Sources
- NHS — Inducing labour
- NICE NG207 — Inducing labour
- Cochrane — Induction of labour at or beyond 37 weeks' gestation
- Cochrane — Membrane sweeping for induction of labour
- PLOS Medicine — Risks of stillbirth and neonatal death with advancing gestation at term
- Human Reproduction — Length of human pregnancy and contributors to its natural variation