40 Week Baby Development Chart

This is when you will have your period and, for now, there isn’t even a baby present. You still have some early planning and date keeping to do.

Conception usually happens in the fallopian tube and although it is by any standards a significant moment, there are no outward signs that fertilisation has occurred...

Once the fertilised egg or zygote has nestled into the wall of your womb, signals will be sent to your body to produce more oestrogen and progesterone...

The placenta has started to form by now and will play a vital role in producing specific hormones and in feeding your baby.

It is now that a heartbeat may be seen on an ultrasound and the eyes and ears of the embryo are being formed.

If you suspect you are pregnant, but haven’t already done a pregnancy test, do one now.

You are now officially just over halfway through your first trimester. Your baby has grown about 10,000 times bigger!

This week your baby is around 1 cm long and can officially be called a foetus.

At this time, baby’s mouth and tongue are starting to form. The hands, which until now have been webbed, will start to separate into fingers.

The foetal heart is dividing into four chambers and can now be heard with a Doppler ultrasound.

By now, the foetus’ genitals have clearly formed, but it is still too early to tell whether you will be having a boy or a girl.

The foetus now has all of its vital organs and the nervous system pathways have formed.

Your baby is as cute as a peach this week and around the same size too.

Welcome to your second trimester! All the hard work involved in making your baby and helping it form has been done

This week your baby can swallow. It will soon become adept at swallowing the amniotic fluid and recycling it through its kidneys.

Your baby is almost 13 cm long this week and moving quite actively now, with alternating periods of rest and activity.

Your baby’s body will begin to straighten out and the legs are getting longer.

If this is your first pregnancy, you will probably be aware of your baby’s movements by now.

This week your little one is the size of a mango.

Welcome to your second trimester! All the hard work involved in making your baby and helping it form has been done

Your baby is around 21 cm long. If you haven’t been able to determine it before, it is now possible to see what sex your baby is via an ultrasound.

Your baby is the length of a banana this week. Baby’s arms and legs look as if they are in proportion to each other and those kicks you are feeling are less random and sudden.

Your baby is hearing a lot of muffled noises by now so get into the habit of talking, playing music and having your partner chat away through your tummy wall.

Your baby is around 22 cm long. The amniotic fluid is being sucked in and out of baby’s lungs in a breathing motion.

Air sacs are forming in your baby’s lungs, in preparation for its first breaths.

Your baby’s eyes can actually see and you may find that baby is more active when you are out in bright sunlight.

There’s lots of movements and activity this week, with regular bursts of kicking and stretching.

Getting to the start of your third trimester really is the beginning of the countdown to when you will be having your baby.

Your baby has gained 300-400 grams this week. This is one of the reasons why so much time is spent sleeping.

Your baby’s brain is maturing at a fast rate this week, so eat lots of brain food and head to the fish market.

There’s lots of movements and activity this week, with regular bursts of kicking and stretching.

Your baby is spending a lot of its time sleeping. When it is awake you may see your tummy rolling as it changes position.

Your baby is gaining lots of weight this week, up to 450 grams.

Your baby is blinking, moving, grabbing and grasping, not knowing it’s doing these things of course as conscious thought and intent are still months away

Your baby is around 50 cm long this week with its brain developing at an enormous rate.

From this week on your baby could drop down into your pelvis, i.e. ‘engage in your pelvis’.

If a baby is born in this week, their lungs would be able to work effectively.

From this week on, your baby is considered “term” and may be born anytime from now on, so be prepared.

It’s all systems go from now on. Your baby is virtually ready for independent life and is preparing for birth.

You’re there - ready to pop at any moment! It’s not entirely clear what causes the onset of labour.

You’re probably short-tempered even with your own shadow this week, waiting in anticipation for “D” day.