Pregnancy Week by Week - Week 16-20

Pregnancy Week by Week - Week 16-20

Month 4-5

Your second trimester is in full swing in your fourth month of pregnancy. Early symptoms like morning sickness should wear off by now, and with any luck you might experience a much-needed energy boost.

Your baby is getting longer and longer, and your bump will now be measured at your antenatal appointments to make sure it is growing as it should.

You will start to notice considerable weight gain at this point. Increased appetite and cravings are also common in your fourth month, as your body is working overtime to pump blood and oxygen to the womb. Giving into cravings is perfectly fine, as long as you eat in moderation and stick to a healthy balanced diet overall.

Due to your expanding bump, stretch marks may start appearing on your body. Your skin is stretching faster than normal, and lines on your tummy, thighs and boobs are completely normal. The colour of your stretch marks may vary, and you may notice some itchiness.

You might also notice varicose veins popping up, typically on the legs. These are swollen veins close to the surface of the skin, they’re not usually harmful but they may give you some discomfort if you stay in the same position for too long.

As your bump grows, your rib cage expands to accommodate your baby and relieve pressure on your lungs. This can lead to pain in your ribs, as well as shortness of breath and breathing difficulties. Pins and needles, cramping and discomfort is also common at this stage due to the added pressure on your nerves and blood vessels.


At 4 months pregnant, the baby’s tastebuds start to form. They can’t open their eyes just yet, but they can hear your heartbeat and even your voice. Now is a good time for you and your partner to start speaking to the baby so they can recognise your voice when they are born. You could even sing to them and play music.

Your bundle of joy starts off this month at the size of a pear. As the weeks progress, bump grows from an artichoke to a mango and then finally a whole banana!

baby size of banana

If you aren’t already showing, the bump will likely start protruding at 4 months pregnant. You should also feel your baby kicking and moving around in the womb. If you haven’t felt anything by 24 weeks, get in touch with your midwife or doctor.


Gender Reveal

Around this time you will be due for another scan. This is a detailed antenatal scan, sometimes called an anomaly scan as it involves checking the baby’s heart, brain and lungs.

This is also your opportunity to find out the sex of your baby!

A lot of couples choose to find out the sex for a number of reasons. Not only does it make you excited for your son or daughter, but it means you can prepare for the new arrival, decorate your nursery and shop for baby clothes. If you’re struggling to decide, here are some pros and cons to consider.


  • You can pick a name. When you know the sex of the baby, you can pick out a name for certain instead of having a couple of options. This means you can get things personalised too.
  • You feel more connected to the baby. Knowing a bit more about them helps you feel more connected to your little one.
  • You won’t be disappointed. If you have your heart set on a girl or boy, finding out now will minimise your disappointment and give you time to come to terms with it.


  • It’s one of life’s truest mysteries. Very few things in life are a genuine surprise, but this is the biggest one of them all.
  • It’s fun. The excitement of your new arrival is made all the more fun when you find out the gender on the same day.
  • It’s traditional. For those who appreciate the more traditional and natural things, waiting to find out the gender is totally normal.
  • You don’t get the wrong information. Mistakes happen, and sometimes people get it wrong. If you never know, you can’t be misinformed.



  • Tell your employer. Legally you are obliged to inform your employer no later than 25 weeks. You can then discuss your maternity leave in detail and look into your options, for example if you want shared parental leave. Employers also have a duty to perform risk assessments to make sure that your job is safe to do while pregnant. If not, adjustments must be made so you can continue to work.

  • Practise yoga or meditation. These exercises can help with your breathing and alleviate aches and pains throughout pregnancy. You can even find prenatal yoga classes uniquely designed for pregnancy.

  • Sign up for antenatal classes. These classes are intended to help you prepare for birth and meet other mums-to-be. This is a great opportunity to learn something new, ask questions and get advice from professionals and other expectant parents.


  • Eat anything dangerous. As your appetite grows and your cravings begin, it’s important to find out what you can and can’t eat. Diet is really important throughout pregnancy, so make sure you know which foods are harmful and what you need to avoid.

  • Squeeze into your old clothes. As your bump gets bigger, you might need to invest in maternity clothes. This saves you worrying about fitting into your regular wardrobe as your pregnancy progresses.