In association with professional midwife experts at birthEd, find out everything you need to know about pregnancy at 5 weeks, including how your baby is growing, changes to expect in your body and pregnancy health, nutrition and wellness advice.

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5 Weeks Pregnant – Your baby, your body & you

Your Baby

5 Weeks pregnantYour embryo is now the size of a lemon seed and is often described as looking like a tadpole because it has a rudimentary head and a tail with a neural tube running from its head to its ‘rump’ which is the pre-spinal cord and brain.

Your embryo is now made of three layers. The top layer — the ectoderm — will become your baby’s outermost layer of skin, central and peripheral nervous systems, eyes, and inner ears.

Your baby’s heart and a primitive circulatory system will form in the middle layer of cells — the mesoderm. This layer of cells will also serve as the foundation for your baby’s bones, ligaments, kidneys and much of the reproductive system. Because the circulatory system is one of the first to develop, it may even be possible to see your baby’s heart beating on an ultrasound as early as 5 ½ – 6 weeks. It begins as two tiny heart tubes which will soon fuse together to form a fully beating heart.

The inner layer of cells — the endoderm — is where your baby’s lungs and intestines will develop.

Your Body

You may have already experienced some early pregnancy symptoms which could have been how you first suspected your pregnancy. These include bloating following the first weeks of conception; nausea, tender breasts, mood swings, increased saliva and exhaustion.

These symptoms are all very common and occur due to the massive hormonal changes that are happening in your body – more specifically your oestrogen, progesterone and human chorionic gonadotrophin levels.

The increase of oestrogen helps to keep your progesterone and HCG levels up. Progesterone controls the function of your placenta, it also grows breast tissue and stops your uterus from contracting. The hCG supports your little lemon seed until the placenta is ready to take over around weeks 10-12.

Preparing for Baby

Iodine is an essential nutrient required to support normal brain growth and development. It is important that unborn babies and infants receive enough iodine. New Zealand soils are naturally low in iodine and your body’s requirements for iodine increase during pregnancy and breastfeeding.

It is recommended to take 0.150 milligram (mg)/150 microgram (mcg or μg) iodine only tablet daily during pregnancy. This can be purchased at pharmacies (or for a lower cost, ask for your doctor or LMC to write you a script).


A missed period? The fifth week of pregnancy, which is also the third week after conception, is often a common time to find out you are pregnant. Your hCG levels have increased by around 15x what they were last week, which means they’re high enough to confirm your pregnancy on an at-home pregnancy test – this is possibly how you found out.

Now that you know you’re pregnant it is important to start thinking about the food you are eating to keep you and your growing baby safe, particularly for these early weeks. By taking basic food safety steps you can prevent most foodborne illnesses.

A common foodborne illness is listeria. A Listeria infection is caused by eating foods contaminated with listeria monocytogenes bacteria. Listeria can be particularly dangerous for pregnant women and can cause miscarriage, preterm birth, stillbirth or infection in your baby. The best way to avoid listeria is to avoid high risk foods and always follow food safety guidelines. We’ve listed some below to keep in mind with food preparation at home.

Clean – Be sure to wash and dry your hands thoroughly before preparing any food. Keep clean tea towels and hand towels in your kitchen. Cover your food once prepared. Rinse all fresh fruit and vegetables before eating.

Cook – Keep all raw and cook food separate. Be sure to cook and reheat food thoroughly – stir your food to ensure it is completely heated through. All meat should also be cooked through. Avoid leaving food out for more than two hours.

Chill – Fridges should be 5c or lower. Freezers should be cold enough that the food is frozen solid. Be sure to cover food before storing in the fridge or freezer.

We recommend visiting Food Safety for a guide list of foods safe and unsafe to eat during pregnancy. They also add information about restaurants and takeaways.

Your Relationships

Navigating conversations around pregnancy can bring up a whole range of emotions. You may be feeling excited, unsure, overwhelmed or scared – to name a few. If you haven’t already had an initial conversation about your news with your partner, we have some tips to help prepare you going into this talk.

First, take some deep breaths and come back to being centered where you are right now. This can help to calm your mind if it’s racing. Acknowledge to yourself how you are feeling. What are the sensations you are feeling in your body?

When you are ready to begin the conversation make sure that the context is right – can you be with your partner for an extended amount of time or do they need to rush off? Do you have privacy? If not now, then plan a time for this conversation.

You may want to share how you are feeling, they may also want to share how they are feeling – remember that their feelings are also completely valid. Listen to their response and repeat back what you are hearing in your own words. Clear and honest communication can be powerful for challenging conversations.

This Week’s Preparation

Pick up and take a daily iodine supplement. This is to be taken throughout your pregnancy and breastfeeding. Continue taking a prenatal vitamin and additional folic acid if there isn’t 800mg in your vitamin
Listen to your body, if you need to rest then rest.
Take some space to yourself to prepare for the conversation of sharing the news of your pregnancy with your partner.
If you haven’t already, check any medications or supplements you are taking with your GP to ensure they are safe to take during pregnancy.
Don’t drink alcohol from the moment you know you are pregnant (see Week 2 for the risks)
Stop smoking, vaping, drinking and using drugs - Visit Quitline to find out about these services
Cut back on your caffeine intake
Increase your consumption of fruit and vegetables and cut back sugar and fat
Get your Rubella immunity checked
Wash hands after contact with a cat or other animals
Go back and read the previous weeks for information you may have missed

Back to 52 Weeks of pregnancy.

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This information was compiled by the Kiwi Families team.

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