Baby development at 5 weeks

Your baby’s vital organs are developing fast, including their heart.

What does my baby look like? And, what size is my baby?

In week 5 of pregnancy, your baby, technically called an embryo, measures a little over 1mm long – that’s roughly the size of a sesame seed. But already their brain, spinal cord and blood vessels are beginning to develop, albeit on a microscopic scale. Their circulatory system is also developing and it’s at around the end of week 5 that your baby’s heart starts to beat.

Meanwhile, the umbilical cord, which will deliver nutrients to your baby, is beginning to form. The amniotic sac, soon to be filled with a clear, pale fluid to cushion your baby, starts to take shape too.

Pregnancy at 5 weeks (first trimester)

What’s happening in my body?

This may be the week that you find out for certain that you’re pregnant. If you’re not convinced by the absence of your period or other symptoms such as tender breasts and tiredness, at 5 weeks your hormone levels should be high enough to confirm the news on a home pregnancy test.

Early pregnancy symptoms at 5 weeks

Early pregnancy symptoms vary from person to person. At 5 weeks, you may experience any of the following signs of pregnancy, or no symptoms at all:

Your breasts may become larger and feel sore. You may also find your nipples stick out more than usual and darken in colour as your body begins to prepare for breastfeeding.

During the first 12 weeks, hormonal changes can leave you feeling tired or exhausted.

Morning sickness affects up to 80% of mums-to-be in the first trimester. It can strike at any time of the day or night and varies from mild nausea to sickness throughout the day.

The pregnancy hormone progesterone slows down your digestion which can lead to bloating and excess gas.

Light cramping and spotting are common in the early stages of pregnancy. If the pain becomes severe (stronger than period cramps) or if bleeding becomes heavy, you should talk to your GP.

Frequent trips to the bathroom are one of the most common symptoms of early pregnancy, as your growing uterus begins to put pressure on your bladder.

Pregnancy hormones, oestrogen and progesterone, soar during the first 12 weeks of pregnancy, affecting how you’re feeling emotionally. Get plenty of rest and light exercise to keep you feeling like yourself.

Any more questions?

Our specialist baby advisors and experienced mums are here to talk and ready to help whenever you need them. You can call us or reach us on Live Chat 8.30am-5.30pm Monday-Friday.

Phone

Call 1800 570 570

FAQs

For all the latest information

Email Us

Send us an email

WhatsApp

8.30 am - 5.30pm Monday-Friday

x