Pregnancy Week 34: Whooping Cough Vaccine and Your Baby Dropping

9 min read

Quick answer: At 34 weeks your baby measures around 45cm and weighs about 2.1kg, and most babies have turned head-down ready for birth. The NHS recommends the whooping cough vaccination between 16 and 32 weeks, ideally around 20 weeks. If you missed it, you can still have it later, even after the birth, but your baby is less likely to get protection from you. If your baby is breech, your midwife will discuss options such as ECV at 36 to 37 weeks.

What parents need to know

You're at 34 weeks — with just six weeks to go, the end is in sight! This week brings an important antenatal appointment. If you have not had the whooping cough vaccine yet, ask your midwife or GP about it. Your baby is also beginning to settle into a head-down position in preparation for birth. Let's look at what's happening this week.

Length	Around 45cm crown to heel
Weight	Around 2.1kg, like a small watermelon
Weeks to go	Six weeks until your due date
Whooping cough vaccine	Offered 16–32 weeks, ideally around 20 weeks
ECV timing	Usually offered between 36 and 37 weeks

How big is your baby at 34 weeks?

Your baby now measures approximately 45cm from crown to heel and weighs around 2.1 kilograms, roughly the weight of a small watermelon. Their skin is becoming smoother and pinker as fat continues to be laid down beneath the surface.

What's happening with your baby?

The majority of babies have turned head-down by 34 weeks, though there is still time for those who haven't. At your 34-week appointment, your midwife will check your baby's position by feeling your bump (a technique called palpation). Your baby's fingernails are now fully grown and some babies scratch themselves in the womb, which is why some newborns arrive with tiny scratches on their faces. The vernix caseosa (the white waxy coating on your baby's skin) is thickening as birth approaches.

The whooping cough vaccination

The NHS recommends that all pregnant women receive the whooping cough (pertussis) vaccination between 16 and 32 weeks of pregnancy, with the ideal time being around 20 weeks. If you missed it, you can still have it later, even after you give birth. This is not ideal, as your baby is less likely to get protection from you, but it helps protect you from whooping cough and from passing it on to your baby. The vaccine works by triggering your immune system to produce antibodies, which are then passed to your baby through the placenta before birth. These antibodies protect your baby in the first weeks of life before they are old enough to be vaccinated themselves at 8 weeks. Whooping cough can be extremely serious and even fatal in very young babies. The vaccine is safe in pregnancy and does not contain live bacteria, so it cannot cause infection.

Birth presentation and breech babies

At 34 weeks, if your baby is still in a breech position (bottom or feet down), your midwife will discuss options with you. Most units offer a procedure called External Cephalic Version (ECV) between 36 and 37 weeks, where a doctor attempts to turn the baby by applying pressure to the outside of your abdomen. ECV has a success rate of around 50% and carries a small risk of complications, so it's done in a hospital setting. If ECV is unsuccessful or you prefer not to have it, your care team will discuss the options for a planned caesarean or, in some units, a planned vaginal breech birth.

What's happening in your body?

You may notice that your bump has dropped lower, a sign that your baby is moving down into the pelvis in preparation for birth. This is known as 'engagement' or 'lightening'. For first-time mothers, engagement often occurs in the last few weeks of pregnancy; for subsequent pregnancies, the baby may not engage until labour begins. When the baby drops, you may find it easier to breathe but experience increased pressure on your bladder.

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.

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 34 checklist

This week:

Attend your 34-week midwife appointment.
Receive your whooping cough vaccination if you haven't already.
Ask about your baby's position.
Finalise your birth plan.
Make sure your hospital bag is complete.

Frequently asked questions

Can I still have the whooping cough vaccine at 34 weeks?

Yes. The NHS recommends it between 16 and 32 weeks, ideally around 20 weeks, but if you missed it you can still have it later, even after you give birth. This is not ideal, as your baby is less likely to get protection from you, so speak to your midwife or GP if you have not had it.

Is the whooping cough vaccine safe in pregnancy?

The vaccine is safe in pregnancy and does not contain live bacteria, so it cannot cause infection. It triggers antibodies that pass to your baby through the placenta, protecting them before their own vaccinations at 8 weeks.

What happens if my baby is breech at 34 weeks?

Your midwife will discuss options. Most units offer External Cephalic Version between 36 and 37 weeks, with around a 50% success rate. If it is unsuccessful or declined, your team will discuss a planned caesarean or vaginal breech birth.

What does it mean when your bump drops?

It means your baby is moving down into the pelvis ready for birth, known as engagement or lightening. You may find breathing easier but feel increased pressure on your bladder.

Sources & further reading

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