Pregnancy Week 38: The Final Countdown — Your Body Preparing for Labour

8 min read

Quick answer: At 38 weeks your baby is fully term and ready to be born at any point, measuring around 49.8cm and weighing about 3.1 kilograms. Your cervix is softening, thinning and starting to open, which may cause irregular cramping or a show. Early labour can last hours or days, so rest at home and contact your maternity unit with any concerns.

What parents need to know

At 38 weeks, your body is working hard behind the scenes to prepare for labour and birth. Your cervix is softening, thinning, and beginning to open in a process called ripening. Meanwhile, your baby is continuing to gain a small amount of weight each day and is fully ready to greet the world. The waiting can feel intense, but labour will begin when both your body and your baby are ready.

Baby's length	About 49.8cm crown to heel
Baby's weight	Around 3.1 kilograms
Size comparison	Roughly a small pumpkin
Established labour	Cervix fully effaced, dilated to at least 4cm
Appointment checks	Blood pressure, urine, fundal height, baby's heartbeat

How big is your baby at 38 weeks?

Your baby now measures approximately 49.8cm from crown to heel and weighs around 3.1 kilograms, roughly the weight of a small pumpkin. They're considered fully term and ready for birth at any point from now.

What's happening with your baby?

Your baby is continuing to build up their fat stores, which will help regulate their body temperature after birth. They're also swallowing amniotic fluid and producing meconium in their intestines — the dark, sticky first bowel movement they'll pass in the first day or two of life. Your baby's immune system has received a significant boost from the antibodies you've passed through the placenta, and if you're breastfeeding, they'll receive further immune protection through colostrum and then breast milk after birth.

Understanding cervical ripening and early labour

Labour doesn't happen all at once. In the days and weeks before active labour begins, the cervix undergoes significant changes. It softens (a process described as 'ripening'), becomes thinner (effacement), and begins to open (dilation). These changes happen gradually and may not produce any noticeable symptoms, or they may cause irregular cramping or a show. By the time you are in established labour, the cervix will be fully effaced and dilated to at least 4cm.

Early or 'latent' labour can last for hours or even days, with irregular contractions that don't yet fall into a regular pattern. This can be exhausting. During this phase, it's advisable to stay at home, rest as much as possible, stay hydrated, eat light snacks, and use a TENS machine or warm bath for comfort. Contact your maternity unit if you're unsure or worried about anything. Call your midwife or maternity unit immediately if your baby is moving less than usual, your waters break, or you have vaginal bleeding, and call 999 if the bleeding is heavy (soaking a period pad soon after putting it on).

Your 38-week appointment

At your 38-week appointment, your midwife will check your blood pressure and urine, measure your fundal height, check your baby's heartbeat, and discuss any concerns. They may also discuss what happens if your pregnancy goes beyond 41 weeks, including the option of a membrane sweep or induction of labour.

Caring for yourself in the final stretch

These last weeks can feel physically and emotionally demanding. Rest whenever you can, as you'll need your energy for labour. Eat nutritious, easily digestible foods. Accept help from family and friends with practical tasks. Try to do something enjoyable each day, whether that's watching a film, taking a gentle walk, or meeting a friend for a decaffeinated coffee.

When to get help

Some symptoms in pregnancy can be a sign of something serious and need checking quickly. This is who to contact, and how soon.

Call 999 if:

you're bleeding from your vagina and the bleeding is heavy (soaking a period pad soon after putting it on), or you also have severe pain in your tummy, pain in your shoulder, or feel sick, faint, dizzy or lose consciousness
you think your baby is coming now and you have a strong urge to push (ask for an ambulance)
you have severe difficulty breathing (you're gasping, choking or not able to get words out) or your chest feels tight or heavy
you have pain and swelling in one leg and you also feel short of breath or have chest pain. A blood clot in the leg can travel to your lungs, which can be life-threatening
you have possible signs of sepsis, such as breathing very fast, being confused or having slurred speech, blue, pale or blotchy skin, a rash that does not fade when you press it, or a very high or very low temperature. Being pregnant makes sepsis more likely
you do not feel you can keep yourself safe (a mental health emergency is as serious as a physical one)

Always call 999 if you think it's a life-threatening emergency, no matter what stage of pregnancy you are.

Call your midwife or maternity unit now if:

your baby is moving less than usual, you cannot feel your baby moving anymore, or there is a change to your baby's usual pattern of movements
you have light bleeding or spotting, even if you have no pain or only mild tummy pain
you have stomach pain that is severe or does not go away after you've rested for 30 to 60 minutes, or stomach pain with regular cramping or tightenings, lower back pain, or pain when you pee
you're less than 37 weeks pregnant and you have a gush or trickle of fluid from your vagina (this could be your waters breaking), regular contractions or tightenings, period-type pains, or backache that's not usual for you
your waters break, even if labour has not started
you have signs of pre-eclampsia: a severe headache that does not go away with simple painkillers, vision problems (such as blurred vision or seeing flashing lights), pain below the ribs, sudden swelling of the face, hands or feet, feeling very unwell, heartburn that does not go away with heartburn medicines, or being sick (vomiting)
your skin is very itchy (for example, it keeps you awake at night), the palms of your hands or soles of your feet are itchy, or the itching is worse at night. This can be a sign of a liver condition called intrahepatic cholestasis of pregnancy (ICP) that needs urgent treatment
your breathlessness comes on suddenly, you're out of breath when you're lying down, or you're breathless and also have chest pain or feel dizzy
you have pain or swelling in one leg, usually in the calf or thigh. This could be a blood clot (deep vein thrombosis, or DVT), which is more likely when you're pregnant
you have a high temperature (38C or above), or you feel hotter than usual or shivery. A high temperature can be a sign of an infection, so it's important to get it checked
any of your contractions last longer than 2 minutes, or you're having 6 or more contractions every 10 minutes

If your baby's movements change, do not wait until the next day: call immediately, even if it's the middle of the night. Do not use a home doppler to check the heartbeat yourself. Even if you hear a heartbeat, this does not mean your baby is well.

If your waters break, use a period pad (not a tampon) so your midwife can check the colour of the waters, and tell them immediately if the waters are smelly or coloured.

Call your midwife or maternity unit for guidance if you think you're in labour, or you're having regular contractions coming every 5 minutes or more often.

You can also call your midwife or maternity unit if you're unsure or worried about anything.

If you cannot reach them, or you're not sure what to do, call NHS 111.

Speak to your midwife or GP if:

you're worried about your mental health, or stress, anxiety or low mood are affecting your day-to-day life. If you need urgent help for your mental health, call 111 and select the mental health option, or ask for an urgent GP appointment

Go to sleep on your side. From 28 weeks, the safest position to go to sleep is on your side, either left or right. Research suggests that, after 28 weeks, falling asleep on your back can double the risk of stillbirth. This includes daytime naps. If you wake up on your back, just turn onto your side and go back to sleep.

Your week 38 checklist

This week:

Attend your 38-week midwife appointment.
Discuss your options if pregnancy goes past 41 weeks.
Rest and preserve your energy.
Stay hydrated.
Contact your maternity unit immediately if you have any concerns.

Sources & further reading

General information, not individual medical advice. Speak to your GP, midwife or health visitor about your baby’s needs.