24 weeks pregnant

How big is your baby at 24 weeks?

About the size of a corn on the cob — around 30 cm (11.8 in) long head to heel, according to the NHS, weighing roughly 665 g (1 lb 7 oz).

Everything is now in proportion. Compare your own scan numbers on our baby size by week chart.

A note on the numbers: from week 20 the NHS measures head to heel, not head to bottom. Weights here are the median of the WHO fetal growth charts — half of babies weigh more, half less, and a scan estimate can be out by 10 to 15 per cent either way. A number below the median is not a diagnosis.

What's developing this week

The NHS is brief on anatomy this week and blunt on meaning: your baby is simply a smaller version of one who has been in the womb longer, and if born now there is a chance of survival with a neonatal unit helping them breathe, feed, keep warm and fight infection. Breathing is the hardest of those.

What "viable" actually means at 24 weeks

The NHS week 24 page says your baby is now considered viable: they could survive if born now with the right support. That is true, and it is the most misread sentence in pregnancy.

Part of the 24-week line is definitional: in the UK a loss before 24 weeks is registered as a miscarriage and a baby born dead from 24 completed weeks as a stillbirth. That boundary governs paperwork, not survival.

The clinical picture is a gradient that differs by country and by unit. The BAPM framework used across the UK, updated in February 2026, asks teams to decide on a baby's individual risk profile rather than gestational age alone. Its England and Wales figures for 24-week births in 2020 to 2021: around 64 per cent of babies alive at the onset of labour survived to discharge, and around 1 in 5 survivors had a severe impairment at two years. ACOG, using US, English and Australian data, reports survival to discharge of 42 to 59 per cent, and notes that outcomes at 23+6 may resemble 24+0 far more than 23+0.

There is no single global threshold; the numbers that matter are your own team's.

What you might feel

Hunger, with force — though the NHS is blunt that you do not need to eat more than usual until the third trimester, which it dates from week 28. Aches spread to ribs, back, breasts and the sides of your bump, where stretching supports cause round ligament pain. Heartburn, leg cramps, swollen hands and feet, nosebleeds and dizziness are all on the NHS list for this week.

There is no target number of movements: the NHS is explicit that you do not need to count kicks. What matters is your baby's usual pattern, and calling immediately if it reduces, weakens or changes. Our kick counter describes a pattern; it does not score one.

If you have felt no movement at all by 24 weeks, tell your midwife this week — NHS, RCOG and Tommy's all name that point.

Is 24 weeks pregnant 5 months or 6 months?

Week 24 is the second week of month 6, with four weeks of the second trimester left by NHS reckoning.

There is no official weeks-to-months map. A calendar month averages about 4.3 weeks, not 4, so 40 weeks is a little over nine months, and two apps can disagree. The most widely used mapping:

• Month 1 — weeks 1 to 4
• Month 2 — weeks 5 to 8
• Month 3 — weeks 9 to 13
• Month 4 — weeks 14 to 17
• Month 5 — weeks 18 to 22
• Month 6 — weeks 23 to 27
• Month 7 — weeks 28 to 31
• Month 8 — weeks 32 to 35
• Month 9 — weeks 36 to 40

Your maternity team will not use months. Everything is booked by week and day — "24 weeks and 3 days" — because a few days change what is offered.

What's happening at your appointments around now

The glucose window opens this week. In the UK, testing is offered between 24 and 28 weeks to people with a higher chance of gestational diabetes. NICE guideline NG3 screens by risk factor — a BMI of 30 or over, a previous baby of 4.5 kg or more, previous gestational diabetes, a first-degree relative with diabetes, or a high-prevalence ethnicity — using a 75 g two-hour oral glucose tolerance test. That is not universal: ACOG says every pregnant woman should be screened between 24 and 28 weeks, and RANZCOG describes routine screening at 26 to 28 weeks.

The next UK appointment is 25 weeks for a first baby, 28 weeks otherwise. If you have not had the whooping cough vaccine, raise it now — the NHS offers it from 16 weeks and wants it before 32.

Is it safe to fly at 24 weeks pregnant?

Yes, in a straightforward pregnancy, and you are inside the window everyone recommends. The RCOG is unambiguous that occasional air travel is not harmful, with no evidence that flying causes miscarriage, early labour or broken waters. ACOG names 14 to 28 weeks as the best time to travel.

Keep two things apart. The medical position is the RCOG's: the safest time to fly is before 37 weeks with one baby and before 32 weeks with uncomplicated twins, because from those points labour becomes likely. The airline position is a commercial rule — most carriers refuse you after 37 weeks, some set an earlier limit, and from 28 weeks most want a letter from your midwife or doctor, which the NHS warns can cost money and take weeks. An airline rule is not medical advice.

The risk that is real: blood clots

ACOG puts it plainly: any travel of four hours or more — car, train, bus or plane — doubles DVT risk, and pregnancy adds to that. Under four hours the RCOG says you are unlikely to need special measures. Over four hours:

• Loose clothing, an aisle seat, regular walks about the cabin
• In-seat exercises roughly every 30 minutes, and water steadily
• Graduated compression stockings sized for you by a midwife or doctor — ACOG warns that stockings which are too tight or worn wrongly increase the risk instead

Practical points

• Nothing restricts you yet, but the letter requirement starts at 28 weeks.
• Check what maternity and neonatal care exists at your destination, and carry your maternity notes.
• Tell your insurer you are pregnant. The NHS says cover should include care in labour, premature birth and the cost of changing your return date.
• Travel to Zika areas is not recommended; some travel vaccines and anti-malarials are unsuitable.

When to call your midwife or doctor

Maternity units are staffed 24 hours a day, and away from home you can walk into any of them.

Get emergency help now

Call your local emergency number (999 in the UK and Ireland, 911 in the US and Canada, 000 in Australia, 111 in New Zealand) or go to an emergency department if you have:

• Heavy vaginal bleeding, or bleeding with severe abdominal pain
• Abdominal pain you cannot concentrate through
• Fainting or collapse, chest pain, or sudden breathlessness
• A severe headache painkillers do not touch, blurred vision or flashing lights, pain below your ribs, vomiting, or sudden swelling of your face, hands or feet — NHS and ACOG both list these as pre-eclampsia symptoms needing immediate assessment
• Pain, swelling or heat in one calf or thigh, which can be a DVT

Call your midwife or maternity unit today, whatever the hour

• Any reduction, weakening or change in your baby's usual pattern of movements. Call immediately, not in the morning, and do not use a home doppler — hearing a heartbeat does not mean your baby is well
• Regular tightenings, period-type pains, or backache that is not usual for you — the NHS list for possible premature labour, meaning labour before 37 weeks, which affects about 8 in every 100 babies
• A gush or a trickle of fluid, which could be your waters breaking
• Any vaginal bleeding, however light
• Itching without a rash, especially at night or on your palms and soles — it can be intrahepatic cholestasis of pregnancy
• A temperature, feeling generally unwell, or burning when you pee
• You have felt no movement at all by 24 weeks

You do not need to be certain something is wrong. That is what the number is for.