Pregnancy Update: Week 21 – What to Expect

At 21 weeks of pregnancy, expectant parents can begin to feel their baby’s movements more noticeably as the little one grows and develops. This week marks a time of significant growth, with the baby’s senses continuing to mature, including the formation of taste buds. Alongside all of this wonderful development, 21 weeks pregnant symptoms start to become more noticeable too. As the pregnancy progresses, parents may experience noticeable changes in their own bodies, such as weight gain and the emergence of a more pronounced baby bump.

Due dates are only an estimate. Statistically, 96% are incorrect. If you are currently 21 weeks pregnant, then you are due in approximately 19 weeks or 133 days. Due dates are calculated at 40 weeks of pregnancy, but your baby might be born between 37 and 42 weeks. Some are born earlier and some later. Put simply, labour happens when your body and baby are ready!

Use our pregnancy calculator to work out when you might be due.

At 21 weeks of pregnancy, your baby could be in a variety of positions as they continue to develop and grow. The baby might be head-down, facing toward the birth canal, or in a breech position, where their bottom or feet are positioned downward. Alternatively, your little one might be lying sideways in a transverse position. At this stage, it’s important to remember that babies move often, shifting positions as they have ample space in the uterus.

Monitoring your baby’s movements becomes more significant as you progress through your pregnancy. While some variation in movement is normal, a noticeable decrease or change in your baby’s usual pattern of movement could be a cause for concern. In such cases, it’s important to contact your healthcare provider to ensure everything is progressing normally.

The charity Kicks Count emphasises the importance of tracking your baby’s movements in pregnancy. They advocate for expecting parents to start paying attention to their baby’s kicks and movements from 24 weeks onward, but it’s always wise to keep an eye on your baby’s activity earlier on, especially if you feel something isn’t quite right. By keeping track of these movements, you can ensure that you’re catching any potential issues early on, giving you peace of mind as you navigate this exciting stage of pregnancy.

At 21 weeks of pregnancy, your baby is far from being fully developed, but significant progress is being made as they continue to grow and mature. It’s important to remember that each baby develops at its own pace, so some aspects of development may vary slightly. At this stage, your baby is becoming more complex in its structure and functioning, although there’s still a long way to go before they are ready for life outside the womb.

One of the key developments at 21 weeks pregnant is the formation of taste buds, which is a critical step in the development of the baby’s sense of taste. The baby may begin to swallow small amounts of amniotic fluid, and this helps stimulate the development of their taste buds. This early exposure to taste could even be influenced by what you eat, as flavours from your food pass through the amniotic fluid.

In addition, your baby’s skin is undergoing important changes. Up until this point, their skin has been translucent and thin, but by 21 weeks, it is beginning to become more opaque. This is due to the development of subcutaneous fat, which starts to form under the skin. This fat not only helps to improve the baby’s skin appearance but also plays an important role in thermal regulation and provides energy reserves for later stages of growth.

The baby’s muscles and bones are continuing to strengthen as well, and they may be becoming more active, with some babies even beginning to practice sucking motions. Their hearing is also developing at this stage, and they may be able to respond to sounds, including your voice or external noises. However, the baby is still far from fully developed. The organs are continuing to mature, and while the baby can survive outside the womb with extensive medical support at this point, they are still in the early stages of their journey toward full-term development.

Babies don’t breathe in the traditional sense while in the womb – after all, there’s no air in there. However, they do start rehearsing their first breaths in preparation for life outside the womb through something called foetal breathing movements.

These involve tiny muscle contractions that pull amniotic fluid in and out of their developing lungs. This process helps strengthen their respiratory muscles and may even assist the formation of alveoli – the tiny air sacs in the lungs that will eventually exchange oxygen and carbon dioxide after birth.

While these breathing movements can start as early as week 10, they become more regular around now. Since oxygen is delivered through the placenta, babies don’t need to “breathe” constantly yet, so they often go for long stretches without practising at all.

As your baby continues to grow, your body is keeping pace. 21 weeks pregnant symptoms can feel quite varied at this stage – here’s what you might be experiencing this week:

• Your bump is finally ‘popping’

Your uterus is now sitting above your belly button, giving your bump a rounder, more pronounced shape. If you haven’t already, this might be the week your belly truly starts to show.

• Joint discomfort

As your bump grows, your centre of gravity shifts, putting extra strain on your back. Pregnancy hormones also loosen your joints, which can leave you feeling a bit unsteady. To ease any aches and pains, try gentle stretching, stay mindful of your posture, and give your body the support it needs – whether that’s with a well-placed cushion or a comfy pair of shoes!

• Leg cramps and swelling

If your legs decide to wake you up in the middle of the night with a cramp, you’re not alone! These are among the most common 21 weeks pregnant symptoms, thanks to changes in calcium and magnesium levels. Staying hydrated and doing a quick stretch before bed can help keep them at bay. You might also notice some swelling in your feet and ankles, which is just your body holding onto extra fluid. Propping your feet up or wearing compression socks can make a big difference this week.

It’s completely normal to be feeling a bit overwhelmed this week. One moment, you’re buzzing with excitement for what’s to come, and the next, a wave of uncertainty creeps in. Emotional shifts are among the 21 weeks pregnant symptoms that catch many people off guard – hormonal changes are likely amplifying your mood swings, so now is the time to lean into self-care. Whether it’s stealing a quiet moment for yourself, sharing your thoughts with loved ones, or chatting with your midwife about any worries, staying connected can help you feel more grounded.

And remember, you don’t have to do everything by yourself! Let your partner, friends, or pregnancy community lift you up when you need it. Your mental and emotional wellbeing matter just as much as your growing baby – so be kind to yourself and embrace the support around you.

Another of the 21 weeks pregnant symptoms that can come as a surprise: small drops of yellowish fluid leaking from your nipples. This is colostrum, the first milk your body produces in preparation for feeding your baby after birth. Often called “liquid gold” because of its rich nutrients and antibodies, colostrum is packed with everything your newborn will need in their first days of life.

Your body starts producing it this early as part of the natural preparation process for breastfeeding, though not everyone will experience leakage just yet. If you do, it’s completely normal and nothing to worry about. Investing in a pair of soft breast pads is a handy hack if it becomes bothersome, and if you have any concerns, don’t hesitate to check in with your midwife for reassurance.

At 21 weeks, you’re deep into the second trimester, and your body is working harder than ever. 21 weeks pregnant symptoms can feel relentless at times, but every little change is part of the bigger picture of growing your baby. Keep listening to what your body needs – whether that’s extra rest, nourishing food, or a moment to put your feet up. You’ve got this!

Be sure to check out the Butterbean knowledge hub for your week 21 pregnancy symptoms guide and our full weeks pregnant week-by-week guide to everything from the first trimester right through to birth. Did you know we also have courses? Check out our multi award-winning hypnobirthing and pregnancy yoga courses today!

Be sure to check out the Butterbean knowledge hub for your week by week guide to pregnancy plus lots more from birth to babe in arms. Did you know we also have courses? Check out our multi award-winning hypnobirthing and pregnancy yoga courses today!