18 Weeks Pregnant: Symptoms, Bump and Baby Size


What to expect at 18 weeks pregnant – everything you need to know about your body and your baby at week eighteen of your pregnancy.

At 18 weeks pregnant, you’ve officially reached four months! Hang on in there, only five months left to go. By week 18, you’ll begin to notice that your body is rapidly developing in preparation for your little one’s arrival.

Think you missed something? Re-visit what to expect at 17 weeks pregnant or head over to our pregnancy week by week guide for more information at every stage of your pregnancy.

Your Baby at 18 Weeks Pregnant


At this point of your journey, your baby is approximately the same size as a pepper. It weighs around 0.18kg (180kg) and is about 14cm.

Your baby is officially one of a kind as its little fingertips and toes have officially formed.

At this moment, your baby’s digestive system is coming into place. Meconium has formed- meconium is a black tarry substance, usually found in their first few nappy changes. The substance is created as baby swallows amniotic fluid, combing with dead cells and secretions in the intestines.

Alongside the development of the digestive system, your baby’s nervous system is forming as we speak. Nerves are being covered by myelin – a protective insulation of the nerves that continue to grow till their first birthday.

Found out whether you’re having a boy or girl? For a girl, 18 weeks pregnant is the point at which their fallopian tubes and uterus develop, and for a boy, their genitals will now be visible. Both of these can be seen when going for an ultrasound.

Your Body at 18 Weeks Pregnant

By the time you’re 18 weeks pregnant, you are bound to look more and more pregnant by the minute – your uterus and baby are constantly growing.

Depending on the height and weight of your baby, the size of your bump will vary. So, don’t worry if your bump appears to be bigger or smaller in comparison to your pregnant friends who are at the same stage as you.

If you’re concerned, however, speak to your GP about all your pregnancy-related worries.

18 Weeks Pregnant Symptoms

Fetal Movement

From 18 weeks pregnant and beyond, anticipation is running high as you should now be able to feel some kind of movement. Due to baby being so small in size, it will feel like gentle flutters, rather than the usual kicking sensation. But don’t worry if you haven’t felt anything out of the ordinary, as some women feel movement later on down the line rather than sooner.

Bloating and Gas

Feeling a little gassy? The pesky progesterone hormone is the one to blame for that feeling of discomfort and bloating. To reduce this, remember to drink plenty of water, relax as much as possible and to eat lots of fibre. Cut back on the beans; while they’re a great source of protein and fibre, they can be a great cause of this problem.

Leg Cramps

From sleepless nights to constantly needing to go to the toilet, leg cramps have now been added to list of reasons why you cannot sleep. Spasms will hit when least expected, and while experts still don’t know what causes this, regular exercise and stretching can help control it.

Bleeding Gums

As you go further into your path of pregnancy, not only will you notice your belly getting bigger, your gums may slightly swell too. This is caused by pregnancy hormones, which cause your mucous membranes to swell, inflaming your gums and making them more likely to bleed. Consume lots of vitamin C and regular use of non-alcoholic mouthwash can help to prevent bleeding gums.


Edema, more commonly known as body swelling, is usually found in the hands and feet. It’s caused by an increase in bodily fluids that are produced by your body, to ensure there’s extra support for you and your little one. Try to manage this by getting plenty rest and avoiding sitting or standing for long periods of time.

Stretch Marks

Stretch marks will continue to develop as your tummy grows bigger and bigger. Hydrate your skin by moisturising with cocoa butter and consuming plenty of vitamin C. If you’re distressed by your stretch marks after birth, consider visiting a dermatologist to see if you can have your stretch marks removed.

Ultrasound at 18 Weeks

At 18 weeks pregnant, you’re now ready for your next scan. This is known as the fetal anomaly scan, and can usually occur between weeks 18 to 21. The fetal anomaly scan allows you to check the full development of your baby.

For more information on development and milestones at every stage of your pregnancy, visit our pregnancy week by week page.

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