WEEK 13: Growing organs
So many big changes as your baby learns how to swallow and their kidneys start to function. Their skeleton continues to form too – find out how you can help by getting a balanced pregnancy diet.
13 weeks pregnant: Pregnancy tips and nutrition

13 weeks pregnant: Pregnancy tips and nutrition

At a glance

Your complexion will glow, but you might have some pigment spots

Spending 20 minutes per day in the sun can help your skin to produce more vitamin D


Leafy vegetables, fish and eggs are good sources of B vitamins

Avoid swordfish, shark and marlin as these may contain mercury

The bones continue to form and the tiny skeleton is coming together. Baby now weighs around 30g, and is about 7.4 cm in length.

Baby's development at 13 weeks

Lots of amazing things are going on this week. Fingers are folding, mouths are opening and swallowing is happening. Baby can swallow amniotic fluid, which is absorbed by the digestive tract and excreted as urine through the kidneys, which are now functioning beautifully. The skin has started to create melanin, which will be responsible for pigmentation later on. The bones continue to form and the tiny skeleton is coming together. Baby now weighs around 30g, and is about 7.4 cm in length.

Your body

By the end of the third month all those little discomforts of early pregnancy usually begin to fade. So you should find yourself feeling pretty good. Take every opportunity to get outside and enjoy some fresh air, even if it’s not all blue skies and bright sunshine. The suns’ rays, even when filtered through clouds, helps your body synthesize vitamin D, which is essential for you and baby.

Have you noticed your skin looking good? This is one of the great side effects of pregnancy. Hormonal changes stimulate the metabolism, making your complexion look healthier. Keep an eye out for brown spots on the forehead or cheeks though. They’re harmless pigment spots which will go away about three months after your little one arrives. Some people claim that these reveal whether the baby will be a boy or a girl, but that’s just an old wives’ tale!

Pregnancy is a beautiful time and we’ve got some tips to help you feel even more beautiful while nurturing the little one growing inside you.


What you eat is important for your own health and baby’s. A diet with good levels of protein will really help nourish baby’s developing brain and other vital organs.

B vitamins can be found in fish, eggs, vegetables and fortified breakfast cereals. Folic acid, important throughout your pregnancy, is found in green, leafy vegetables. And you can get those essential fatty acids in oily fish, nuts, sunflower and pumpkin seeds. Have a chat to your GP to be sure you are including all the right kinds of foods in your pregnancy diet.

It’s fine for pregnant women to eat fish as part of a balanced diet, as it’s an excellent source of protein. However, there are some types you should avoid during pregnancy.

That’s because some fish have highly concentrated levels of mercury, which is bad for baby’s very sensitive nervous system. Make sure you don’t eat any swordfish, or marlin (from the shark family). And if you’re a fan of tuna, make sure you don’t eat any more than two steaks or four tins per week.

Find a comprehensive list of all types of fish and seafood to avoid and consume.

Pregnancy tips

You’ve probably managed without maternity clothes so far. And you might still have a bit of time time before you need more breathing room in your waistbands. But it’s a good idea to have a look around ahead of time. It’s a great time to buy some comfortable support bras, with adjustable straps if possible. Because your breasts are still growing, there should be nothing to constrict you or pinch you. So you might want to get a proper bra fitting to make sure everything is where it should be. In a few weeks’ time you might need a larger size thanks to your rapidly developing baby, but it’s not time to get a ‘proper’ pregnancy or breastfeeding bra just yet.

12 weeks pregnant: Pregnancy tips and nutrition

12 weeks pregnant: Pregnancy tips and nutrition

prev Previous article
14 weeks pregnant: Pregnancy tips and nutrition

14 weeks pregnant: Pregnancy tips and nutrition

Next article next

Important advice to mothers

The World Health Organisation (WHO) recommends exclusive breastfeeding for the first 6 months of life. SMA® Nutrition fully supports this and continued breastfeeding, along with the introduction of complementary foods as advised by your healthcare professional.