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Pregnancy at week 5

4-minute read

Your baby

By week 5, your baby has burrowed into the wall of your uterus. It is now called an embryo and measures about 2mm from end to end. The foundations for all of the major organs are in place. The baby is inside an amniotic sac, a bag of fluid that protects it.

The cells in the baby are still dividing. In week 5, the brain and spinal column are already starting to form. The spinal cord is called the neural tube and is developing as an open groove. Your baby’s head is much larger than the rest of the body at this stage as the brain and face are developing very rapidly.

Your baby’s heart will start beating this week. The blood vessels are already starting to form and blood is circulating in the baby’s body. A string of blood vessels connects you to your baby, and this will eventually become the umbilical cord.


Your baby at 5 weeks

Length:2mm

Your body

Week 5 is when most women start to wonder whether they may be pregnant. You will have missed your period, but you may be feeling like it’s just about to start. You may notice your breasts are larger and feel sore, and you may be feeling quite tired.

Some women may feel nauseous, or notice they need to go to the toilet more often than usual.

You will also be producing more human chorionic gonadotropin (hCG).

Things to remember

You can do a pregnancy test the day after you miss your period. There are many different tests available, so make sure you follow the instructions carefully.

If the pregnancy test shows you’re pregnant, it’s a good idea to see your doctor as soon as possible. They will confirm you are pregnant and advise you on how to look after yourself and your baby.

Finding out you’re pregnant can be very exciting. But for some women, pregnancy is unplanned. Whether the baby was planned or not, you may feel a range of emotions from joy to surprise to shock.

It’s important not to drink any alcohol, smoke cigarettes or take illicit drugs if you’re pregnant since these can all be very harmful for your baby.

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Call Pregnancy, Birth and Baby to speak to a maternal child health nurse on 1800 882 436 or video call. Available 7am to midnight (AET), 7 days a week.

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