16 weeks pregnant: baby's development, your mental health and antenatal appointments

Your baby is now about the size of a lemon.

Your baby’s development this week 

Did you feel a little flutter? Perhaps a bubbling sensation? This could be your baby moving!

If this is your first pregnancy, you may not become aware of movements until you are more than 20 weeks pregnant. If you have been pregnant before, you may feel them around now. Your baby’s movements might feel like a kick, flutter, swish or roll.

Read more about baby's movements.

If you could see their face, you might be able to see them making facial expressions, like a frown or squint. They can’t control these facial muscles yet though.

Your baby’s nervous system continues to develop, and the muscles in their tiny limbs can flex. They can make a fist and might even grab and pull their umbilical cord.

Your pregnancy symptoms in week 16

Varicose veins in pregnancy

Varicose veins are veins that have become swollen. They may be blue or dark purple, and are often lumpy, bulging or twisted in appearance.

Varicose veins are rarely a serious condition and they do not usually require treatment. But speak to your GP or midwife if you notice varicose veins, especially if they are causing any pain, discomfort or irritation. Varicose veins can be a risk factor for deep vein thrombosis (DVT), a blood clot that can be dangerous if it isn’t treated.

Cramping in your legs?

If you’re being kept awake at night by sudden sharp pains in your leg, try gently exercising your legs, ankles and feet during the day.

Are you suffering from a headache, indigestion or faintness?

Here’s our guide to 10 common pregnancy complaints (and how to avoid them).

What to do in week 16


You’ll be offered the whooping cough vaccine by your GP or midwife around this time. Getting vaccinated will protect your baby from developing whooping cough in the first few weeks of their life. The whooping cough vaccine is safe to take in pregnancy

Your midwife can also advise you about other vaccinations, such as the flu vaccine or covid-19 vaccine.

Can I use cleaning products?

Some people worry that being exposed to everyday chemicals may harm their baby. But research shows that usual levels of exposure to chemicals found in everyday household items are low.

Find out more about chemicals and pregnancy

Your mental wellbeing

If you’re feeling anxious about the pregnancy or any other issues, it’s also worth taking some time out to talk about your feelings with someone close to you. Ask your midwife about any pregnancy-related concerns you might have.

Alternatively, you can call the Tommy's PregnancyLine and speak to one of the midwives on 0800 0147 800; or email us at [email protected].

If you're struggling to cope with your feelings, tell your midwife or doctor how you feel.

You may also want to complete your pregnancy and post-birth wellbeing plan. Our PDF is designed to help you think and talk about your mental wellbeing during and after pregnancy. 

Complete your pregnancy and post-birth wellbeing plan.

Second antenatal appointment

When you’re about 16 weeks pregnant, you’ll have a second antenatal appointment with your midwife to check baby size and fetal development. You may also get to listen to your baby’s heartbeat.

“Hearing my baby’s heart beat was wonderful and so reassuring. I miscarried my first baby and the midwife explained that any time I was worried, we could have a listen in. This was very comforting to know.”

Sara, mum of two

At this appointment, you may also get the results of any blood tests you had at your booking appointment.

At each antenatal appointment from now on your midwife will take your blood pressure and check a urine sample for signs of increased protein. These are ways to make sure you’re not at risk of developing pre-eclampsia, which is a serious pregnancy condition. They will also measure your baby to check their growth.

Don't forget to bring your pregnancy notes with you to your appointments.

Being rhesus negative

Everyone is offered blood tests as part of their antenatal checks and tests to determine whether their blood is RhD negative or positive. This happens during pregnancy when there is an incompatibility between the blood types of the mother and baby.

Being rhesus negative is not a problem in your first pregnancy. But if you have more babies, there is a risk of rhesus disease. This doesn't harm you, but it can cause the baby to become anaemic and develop newborn jaundice.

You may need treatment to prevent rhesus disease. It isn’t very common anymore as it can usually be prevented using injections of a medication called anti-D immunoglobulin if needed. You will be offered this at certain points during pregnancy or after birth.

Exercises to avoid in pregnancy

Being active can help you stay healthy in pregnancy. Exercise is safe and won’t hurt your baby, but there are some things to be aware of.

After 16 weeks, exercising on your back can cause low blood pressure and dizziness for some people. Try to avoid lying on your back for long periods of time. Make sure any exercise instructors you’re working with know that you are pregnant.

Find out more about exercises to avoid in pregnancy and good ideas for exercise.

1. Royal College of Obstetricians and Gynaecologists (2012) Your baby's movements in pregnancy: information for you, London RCOG

2. NHS. You and your baby at 16 weeks pregnant. https://www.nhs.uk/pregnancy/week-by-week/13-to-27/16-weeks/ (Page last reviewed: 13 October 2021. Next review due: 13 October 2024)

3. NHS. Varicose veins. https://www.nhs.uk/conditions/varicose-veins/ (Page last reviewed: 7 May 2020. Next review due: 7 May 2023) Accessed: September 2021

4. NHS. Common health problems in pregnancy. https://www.nhs.uk/pregnancy/related-conditions/common-symptoms/common-health-problems/#Cramp (Page last reviewed: 8 March 2021. Next review due: 8 March 2024)

5. NHS. Whooping cough vaccination in pregnancy. https://www.nhs.uk/pregnancy/keeping-well/whooping-cough-vaccination/ (Page last reviewed: 17 October 2019. Next review due: 17 October 2022) Accessed: September 2021

6. Royal College of Obstetricians and Gynaecologists (2013). Scientific Impact Paper 37. www.rcog.org.uk. (Accessed September 2020)

7. NHS. Rhesus disease. https://www.nhs.uk/conditions/rhesus-disease/ (Page last updated: 16 November 2021 Next review due: 16 November 2024)

Review dates
Reviewed: 11 July 2022
Next review: 11 July 2025