Your week-by-week guide to the second trimester of pregnancy

For many the second trimester is the easiest & most enjoyable stage of pregnancy. Our foetal development guide gives you the lowdown on what’s happening each week

Spanning week 13 to week 27 of pregnancy, the second trimester often brings some welcome changes as morning sickness eases and energy levels return. What’s more, your beautiful bump will start showing and you’ll feel your baby move for the first time!

Week 13

What’s happening to my baby?

There’s plenty going on for your baby this week. At about 23g and 7.5cm from head to bottom, your little one is growing fast. Those tiny features are starting to look more like a cute baby face.

What’s happening to me?

You are now in your second trimester, and this could be something of a relief! Women who’ve had morning sickness often get a reprieve now. It’s also common for energy levels to pick up. Whatever your experience, you can’t miss one of the most noticeable second trimester developments – from now, your belly really begins to round out.

You may be wondering how long you can go on wearing your non-maternity wardrobe. Some women find they need maternity clothes from around week 14, while others can hold off until well into the second trimester.

Week 14

What’s happening to my baby?

This week may bring a crop of hair in the form of a fine all-over fuzz called lanugo (temporary body hair to keep your baby warm in the womb).

What’s happening to me?

The second trimester can mean increased appetite and the easing of any queasiness. It's important to continue eating healthily and perhaps to remind yourself how to stick to a healthy pregnancy diet. You should be able to get all the nutrients you need from a healthy, balanced diet, but if you feel your diet may be lacking in certain nutrients you might want to consider taking a suitable pregnancy supplement. The right nutrients are critically important to your unborn baby. In fact, leading scientists now agree that good nutrition in "the first 1,000 days" (between conception and two) is one of the best ways to set up your baby for a healthy life.

Week 15

What’s happening to my baby?

If you had a window on your womb, you could witness some toe wriggling and other movements. You’re unlikely to feel these yet though (especially if this is your first pregnancy).

What’s happening to me?

How are you feeling? Around now, you could start getting a taste of common pregnancy niggles such as backache and constipation. Even if you’ve been lucky enough to avoid discomfort to date, it’s worth remembering that gentle exercise throughout your pregnancy may help avoid many problems.

Pregnancy's upsides may be making themselves known too. Changes to your hair and skin during trimester two can even bring on that legendary ‘glow’. Maybe it’s time to celebrate your pregnancy journey with a photobook.

Week 16

What’s happening to my baby?

Your baby’s nervous system is now developed enough for your baby to start clenching fists or holding hands, and they’ll be moving around to improve their muscle development and coordination. Because babies develop at different rates, there’s no hard-and-fast rule about when kicking starts, although it does get more likely from now. Most women will start to feel movement between 16 and 24 weeks.

What’s happening to me?

Don’t forget you’re still in the ‘honeymoon trimester’ for the next 12 weeks. That’s not to say you won't experience the odd niggle or two, but the second trimester is often the most comfortable period of pregnancy (especially since your load’s still relatively light). Revel in this time – it’s the ideal window to enjoy some pampering.

Week 17

What’s happening to my baby?

Your baby is around 14cm from head to bottom now and will be starting to lay down body fat. Meanwhile, their eyebrows and eyelashes are beginning to grow and their eyes can now move, although the eyelids are still shut.

What’s happening to me?

For you, there may be some surprises in store. If you get an unexpectedly stuffy nose you can put it down to increased blood flow and pregnancy hormones, which swell up the membranes inside your nose. In fact, some women find that their nasal congestion is enough to disrupt their sleep. Nasal strips and humidifiers are pregnancy-friendly ways to help ease the problem and get a good night’s sleep. It can also help to prop your head up with an extra pillow.

Week 18

What’s happening to my baby?

It’s month five of your pregnancy, and you and baby are approaching the halfway point. Development this week includes the appearance of fingerprints. And that little individual in your tummy will also start yawning and may start hiccupping around now.

What’s happening to me?

For you, the emblem of month five is an unmistakable baby bump. Here’s hoping it brings all sorts of deserved rewards such as a seat on public transport, or a cuppa fetched by your partner while you put your feet up. It’s a good time to thank your belly (and reward your hard-working skin as it keeps stretching) by treating it to a lovely mum-to-be skin treatment or a gentle massage.

It’s also a good time to remember to take a breather when you can – you should especially avoid standing for too long if you’re experiencing swollen feet (see your GP if this continues). Check out our ideas for achievable chill-out strategies.

Week 19

What’s happening to my baby?

Your baby now weighs 220g plus and is about the size of an orange. Babies at this stage are protected by a creamy white substance called vernix, which shields that delicate skin from the surrounding amniotic fluid. Without vernix, your newborn would arrive looking as though they’d spent 20 weeks too long in the bath.

What’s happening to me?

Meanwhile, your miraculous body is changing in preparation for childbirth. Your pelvic joints and ligaments are beginning to relax and loosen, which can affect your balance and the way you stand. So take every excuse to put your feet up, and if you need pain relief, speak to your GP or Boots pharmacist about what’s suitable to take during pregnancy.

Week 20

What’s happening to my baby?

Congratulations! At 20 weeks into your pregnancy, you’re halfway there. Your little one has been busy developing their fingerprints, hearing, and ability to deliver a firm kick. You’ll be offered an ultrasound scan between 18 and 20 weeks – one of the screening tests offered by your GP or midwife – which will tell you more about your baby’s physical development.

What’s happening to me?

Your bump is probably beginning to show. After all, your baby is now about 17cm from head to bottom and weighs about 310g.

For some women, morning sickness should be easing off and a burst of energy kicking in, so maybe it’s time to think about booking a babymoon. Look out for holiday buys, and don’t forget your travel insurance!

Week 21

What’s happening to my baby?

It’s week 21 of your pregnancy and you may well have started to feel a few flutterings (at all hours – your baby’s sleeping and waking patterns aren’t necessarily the same as yours!). Your baby is starting to gain weight at a faster pace now, accumulating fat. They should start to weigh more than the placenta now, which will keep growing, but at a slower rate than your baby.

The big leaps aren’t about to stop, though. Your little one may soon begin to get a flavour of the foods you eat (and getting a taste for them, too) by swallowing a little of your amniotic fluid. As if you needed more motivation to keep up that healthy pregnancy diet.

What’s happening to me?

You’ll be noticing developments of your own, too, and the biggest one is unmistakable – a bump announcing your pregnancy to one and all. Women often talk about how much they love their bumps, but no matter how you feel about your changing shape, it can take some getting used to.

Week 22

What’s happening to my baby?

Your baby now weighs around 450g, and is developing touch, sight, taste and hearing. These more developed senses mean that they may respond if you apply gentle pressure to the bump or sit in a warm (not hot) bath.

What’s happening to me?

You may be experiencing new sensations – from energy bursts and faster growing nails, to pregnancy niggles such as backache, stretchmarks and leg cramps. And there may be some surprises too – anything from thick, glossy hair to growing feet! Your experience will be unique (and can change with each pregnancy).

If you’re experiencing anything out of the ordinary, speak to your midwife or GP. Your Boots pharmacist is also there to support you throughout your pregnancy.

Week 23

What’s happening to my baby?

Your baby in week 23 weighs around 500g, and that will double over the next month or so, while your tummy starts to round out.

Now is the perfect time for big pre-birth plans, from taking a babymoon to scoping out the nursery. While the nesting instinct tends to intensify later, you may also get the urge to do nothing but put your feet up closer to B-Day. If you’re thinking about nesting now, we can help you create the perfect nursery.

What’s happening to me?

Make sure your plans include looking after you. Healthy eating helps but you may be thinking about supplements. Most mums-to-be know folic acid is important from before conception up to the first 12 weeks of pregnancy. But did you know the Department of Health also recommends that pregnant and breastfeeding mums consider a supplement of 10 micrograms of vitamin D a day during autumn and winter, to ensure your vitamin D supplies are sufficient to support your baby’s growth and development?

Browse for supplements to support you.

Week 24

What’s happening to my baby?

Now you’re well into your pregnancy and your baby is getting more, well, baby like. If you could peep inside a porthole to your bump, you’d see eyelashes, eyebrows and a little downy hair framing a face with almost all the features complete. Babies even have a chance of survival if born now. You’d also notice your baby is getting taller: he or she now measures around 30cm from head to heel.

What’s happening to me?

If your midwife has identified that you may be at risk of gestational diabetes they will offer you a blood test to check, and if you do have it you'll be closely monitored during your pregnancy and birth to check for any potential problems. Management of the condition may include changes in diet and exercise, and could involve taking medicines. Your Boots pharmacist can also help you understand and manage diabetes.

Week 25

What’s happening to my baby?

You should have been feeling movements by 24 weeks, so your baby should be really getting going by this week of your pregnancy. Along with lively kicks and punches, you could see a fluttery hiccup or two.

What’s happening to me?

Now your baby’s getting moving, how about you? You probably don’t need us to tell you that gentle exercise will help keep you feeling good. Just remember to consult your midwife or GP before taking up new exercises.

If exercise is warming you up more than before, thank your newly supercharged circulation. Remember to drink plenty of water to help your body’s natural cooling system. Staying well hydrated can also help stave off dizziness spells of which some women experience during pregnancy. It’s best to stop exercising if you feel dizzy, and speak to your GP if it persists or you are concerned.

Week 26

What’s happening to my baby?

You’ve probably noticed your baby moving more than before. With fully developed hearing, they will be reacting to almost any loud noise – even moving in time to music.

What’s happening to me?

All that movement can be reassuring. Then again, a sharp kick isn’t always what you want just as you’re drifting off to sleep. It might be worth teaching yourself a few relaxation techniques, or speak to your GP if you’re really struggling to get enough sleep.

Resting up is extra important in the final months of pregnancy, so get into the habit of making time for yourself. A daily pampering ritual is one way to get your ‘me time’. Consider giving your skin some TLC – especially the skin over your bump, which has months of stretching ahead of it – or treating your feet to a home-pedicure (while you can reach your toes). Explore our products for pregnancy skincare and stretchmarks.

Week 27

What’s happening to my baby?

By now your little one will have a well-developed sense of taste for the foods you eat. Babies even begin to react to flavours around this time, kicking or hiccupping after you’ve eaten spicy food, for instance.

What’s happening to me?

Rich or spicy food may be getting more of a reaction from you these days too. Heartburn and indigestion affect as many as eight in 10 pregnant women, and are more common from now on as your growing baby puts more pressure on your stomach. Ask your GP or pharmacist about dealing with heartburn.

With your second trimester nearly over, it’s not too early to start thinking about your birth plan. It will help you make all the big decisions you’re faced with on the day (and some of the little ones too).