Illustration of a baby at week 24 inside the womb in cross-section, with the placenta and umbilical cord — Womb in cross-section, enlarged to show detail. Not true size.

Second trimester, week 24

24 weeks pregnant: A viability milestone

Size of a: Ear of corn
Length: 30 cm head to heel
Weight: 665 g WHO median
Heart rate: 110–160 bpm typical range
Due date: 112 days away 60% of the way

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Checked against the sources listed on this page. Not reviewed by a clinician. Last updated 5 November 2026. How we check.

At 24 weeks pregnant, your baby is about the size of an ear of corn: roughly 30 cm from head to heel, weighing about 665 g. You’re in your second trimester, with about 16 weeks to go until your due date.

Your baby this week

The lungs are starting to make surfactant, although they are still far from ready.
The inner ear, which controls balance, is developed, so the baby may sense being upside down.
The skin is still thin and translucent, but fat is beginning to fill it out.

Your body this week

Glucose screening for gestational diabetes is usually done between 24 and 28 weeks.
You may notice movements at regular times of the day.
An itchy belly is common as the skin stretches. Severe itching of the palms and soles should be reported (it can be a liver condition, cholestasis).

Typical weight gain so far: 5–7.7 kg
Your uterus: Fundal height ≈ 24 cm (±2 cm)

Weight gain range is for a pre-pregnancy BMI of 18.5–24.9 (IOM guideline). Your provider may advise differently.

What “viability” really means at 24 weeks

It means a baby born now has a real chance of surviving with intensive neonatal care. It doesn’t mean they’d be ready to be born. Estimates vary widely. A UK clinical framework reports survival of 39 to 70% among live-born babies at 24 weeks, depending on the hospital and how the study was done. UK charity Tommy’s says around 6 in 10 survive, and about 1 in 7 of those born at this stage have a severe disability, such as cerebral palsy. It gives around 7 in 10 at 25 weeks and 8 in 10 at 26 weeks.

Every extra week in the womb improves the outlook. So if you have any signs of labour before 37 weeks, call your maternity unit straight away, because there is often treatment that can help.

Learning your baby’s movement pattern

You don’t need to count kicks, because there’s no set number that is right. What matters is getting to know what’s normal for your baby.

Call your midwife or maternity unit immediately if your baby is moving less than usual, you can’t feel movement, or the pattern changes. Don’t wait until the next day, even at night, and don’t rely on a home doppler. Also tell your midwife if you still haven’t felt movements by 24 weeks.

The glucose test: what to expect

Testing for gestational diabetes usually happens between 24 and 28 weeks. In the UK it’s offered if you have a risk factor, such as a BMI above 30, a previous baby weighing 4.5 kg or more, previous gestational diabetes, or a parent or sibling with diabetes. People of South Asian, Black, African-Caribbean or Middle Eastern origin are also offered it. In the US, almost everyone is screened.

The UK test takes about 2 hours. You fast for 8 to 10 hours beforehand (water is usually fine), have a blood test, take a glucose drink, rest for 2 hours, then have a second blood test. US clinics often start with a shorter version. See where it fits in the timeline.

Scans, tests and checkups

This week

Know your baby’s movements Self-care
Get to know your baby’s pattern. If movements slow down, change or stop, contact your maternity unit straight away. Don’t wait until the next day.
This week

Glucose test (gestational diabetes) Blood test
A sugary drink followed by blood sugar checks. The UK offers it based on risk factors. The US screens almost everyone.
From week 27

Whooping cough (Tdap) vaccine Vaccine
Antibodies pass to the baby and protect them in their first weeks. The US recommends 27–36 weeks. The NHS offers it from 16 weeks, usually around 20, and ideally before 32.
From week 28

Anti-D (if Rh-negative) & repeat bloods Blood test
If your blood group is Rh-negative, anti-D immunoglobulin is offered around 28 weeks. Blood count and antibodies are often rechecked.
From week 28

RSV vaccine Vaccine
Protects newborns from RSV, a serious lung infection. The US gives it at 32–36 weeks in RSV season. The UK offers it from 28 weeks. Check local guidance.

See the full scan and test timeline

Real size, next to an adult hand

Adult hand 18.5 cmbaby 20.4 cm curled up

Growth curve

Typical weight by week: WHO median from week 20, approximate before that. Healthy babies vary widely.

When to call your midwife or doctor at 24 weeks

Call your midwife, doctor or maternity unit straight away, day or night, if you have any of these:

A change in your baby’s usual pattern of movement. Call straight away rather than waiting until the next day.
Vaginal bleeding, or a gush or steady trickle of fluid.
Severe belly pain that doesn’t go away.
A severe headache, vision changes, pain under your ribs, or sudden swelling of your face, hands or feet. These can be signs of pre-eclampsia.
Regular tightenings, period-like cramps or lower back pressure that keep coming. This could be early labour.
Fever of 38 °C (100.4 °F) or higher, or pain or burning when you pee.
Pain or swelling in one leg, chest pain, or sudden shortness of breath. These can be signs of a blood clot.
Feeling very low, hopeless or anxious most days. If you feel you might harm yourself, get emergency help.

Based on NHS and ACOG guidance. This list isn’t complete. If something feels wrong, call anyway. In an emergency, call your local emergency number.

Tip for this week

From about 24 weeks, if movements slow down or stop, don’t wait until the next day. Contact your maternity unit straight away.

Myth or fact?

Do babies move less at the end of pregnancy?

Myth

No. Movements may feel different as space gets tight, but the baby should keep moving as much as before, right up to and during labour.

Read the evidence

Common questions at this stage

All common questions

Questions people ask about week 24

What is the glucose test?

A screening test for gestational diabetes. You drink a sugary drink and have your blood sugar measured after 1 hour (or at several points in a 2-hour test). It is usually done between 24 and 28 weeks.

Is a baby born at 24 weeks viable?

Many babies born at 24 weeks survive with neonatal intensive care, but they face significant risks of complications. Outcomes improve with each additional week.

References

Advice differs between countries, so follow your own care team’s plan. Weights from week 20 are the WHO median, and earlier weights are approximate. How we check this.

All 40 weeks

First trimester Weeks 1–13

From conception to a fully formed, tiny fetus. The most rapid change of the whole pregnancy.

Second trimester Weeks 14–27

Growth, movement and senses. Often the most comfortable stretch for parents.

Third trimester Weeks 28–40

Weight gain, brain and lung maturation, and getting into position for birth.