Tommy's PregnancyHub

5 weeks pregnant - all you need to know

It’s week five and your baby’s tiny face is already starting to form - the beginnings of a tiny nose and eyes are already taking shape.

What does my baby look like?

Your tiny baby is 9mm, about the size of a little fingernail now.

Your baby’s hands and feet are still just little buds. Their skull bones close around their tiny, primitive brain.

The outer layer of the cushiony amniotic sac develops into the placenta. Its cells grow deep into the wall of your womb, creating a rich blood supply.

Your placenta will give your baby nutrients (food) and oxygen through their umbilical cord.

It has three vessels: One thick vessel carrying oxygenated blood and nutrients to the baby (they won’t breathe through their lungs until they're born - which is why waterbirths are safe), and two thinner vessels that carry blood containing waste-products back into your circulatory system.

The placenta is a remarkable lifeline that also keeps bacteria and viruses away from your baby.

Get weekly updates on your baby's development from our expert midwives straight to your inbox.

Your pregnancy symptoms in week 5 

Pickles and ice cream – all about cravings 

Have you been having cravings? Or maybe you’ve taken a sudden dislike to one of your favourite foods? Cravings aren’t uncommon in pregnancy but don’t worry if you don’t get any, because that’s very normal too. Read about the 10 most-common pregnancy myths.

What to do in week 5 

Choosing the best nutrition for you and your baby

You might find it hard to believe you are truly pregnant as you are unlikely to have seen a midwife yet, but it’s time to start looking after yourself and your baby. This week we’re looking at food and nutrition in pregnancy.

Your body is working hard to grow a baby but it’s also very efficient, which means there’s no need to ‘eat for two’. You won’t need any extra calories until your final trimester (and at that point you will only need an extra 200 calories a day – about half a sandwich). If you have morning sickness eating small meals often to keep your blood sugar levels steady.

Find out what 200 calories looks like.

Not doubling your calories will also help you manage your weight in pregnancy. Find out more about how much weight you may gain here.

Eating a healthy, balanced diet in pregnancy will give you more energy and ensure your baby gets all the nutrients it needs.

“I used to eat a lot of junk food, but when I was pregnant I took healthy snacks to work instead - fruit, yoghurts and almonds - and I drank a lot of water.” 

Nadia, mum of one

Find out more about managing your weight in pregnancy.

There are certain vital supplements in pregnancy: make sure you take a folic acid supplement to help your baby’s neural tube develop, and vitamin D.

What foods are off limits?

Trying to remember all the dos and don’ts in pregnancy – like which foods to avoid - feels complicated, but don't worry, and don't be too concerned if you have eaten something that is on the list, the risk is small. Talk to your midwife if you can't stop worrying about it. 

Read our tips to avoid food poisoning.

Vegetarian or vegan?

It’s fine to follow a vegetarian or vegan diet in pregnancy but make sure it is varied and includes all the food groups. Learn more about planning your vegetarian or vegan diet to ensure your baby gets enough vitamin B12, riboflavin, iron, zinc, calcium and iodine.

Cutting down on caffeine

Too much caffeine is harmful to a growing baby so it’s important to limit your intake to 200mg a day now that you’re pregnant. You might be surprised to learn that caffeine is not just found in coffee, but also in tea, chocolate and energy drinks! Decaffeinated tea and coffee, fruit juice or water are all good choices if you are used to drinking a lot of caffeinated drinks. Use our caffeine calculator to see how much caffine is in your diet.

  1. Lennart Nilsson (2009) A Child is Born, Jonathan Cape
  2. BMJ (2008) Maternal caffeine intake during pregnancy and risk of fetal growth restriction: a large prospective observational study BMJ 2008; 337 :a2332
  3. NICE (2010)  Dietary interventions and physical activity interventions for weight management before, during and after pregnancy, Public health guidance 27, 2010
Review dates

Last reviewed: 25 June, 2018
Next review: 25 June, 2021