Development

Pregnancy is counted as 40 weeks, starting from the first day of the mother's last menstrual period, so the development chart below does not count the first 2 weeks. The gender and inherited characteristics of the baby are decided at the moment of conception.

Week 1: Around 30hours after conception, the cells are beginning to split & by the 3rd day, the cell (known as a zygote), has divided into 16 cells. By the 5th day, the zygote has migrated from the fallopian tube to the uterus (womb). And on the 7th day (or there abouts) it rests in the plump uterine lining (endometrium). It is know known as a blastocyst.

Week 2: Even though it's tinier than a grain of rice, some of the bodies systems (like the digestive system) are already growing!

Week 3:The evolving neural tube will later become the central nervous system (brain and spinal cord).

Week 4:Your Blastocyst is now called an embryo. It is approximately 3mm in length. It is also at this stage that it secrets hormones that stop the menstrual period.

Week 5: The placenta burrows into the wall to get oxygen & nutrients from Mum & along with the placenta, it has also developed the amniotic sac. The tiny little heart is beating too!

Week 6: At this stage the head is huge compared to the rest of the body which just looks like a tail.It is around 1.3cm in length.

Week 7:The embryo is starting to move around using it's tiny little muscles. The liver is making blood cells & also forming are the eyes, mouth and tongue.

Week 8:Your embryo is now known as a foetus and is about 2.5cm long. The hands and feet are now growing fingers and toes. Veins are clearly visible & the heart has divided into the left & right chambers. There are brain waves & all of the bodily organs are formed!

Week 9: Everything is growing stronger & developing further, even teeth are budding inside the gums!

Week 10:The fingers and toes stuck together with webs of skin, but they are very recognisable now.

Week 11:Your baby is now about 7cms long & is quite the little swimmer in there!

Week 12: A dark vertical line of pigmentation, called the linea nigra, may appear on your abdomen, but will soon disappear after the birth. Nails are growing, eyes are fully developed & are fused over with the eyelids. It also has vocal cords! Your baby may even be sucking its thumb.

Week 14: Your baby is getting very coordinated with it's movements now.

Week 16: Your baby may be getting the occasional hiccups! Maybe it's from all that amniotic fluid! Your baby now also has taste buds, eyebrows & eyelashes plus is now around 14cm long.

Week 20:If you haven't started already, now is a fantastic time to start talking & singing to your baby because the ears are fully functioning! The sex of your baby can also be determined at this stage. It also has fingerprints & measures approximately 21cms!

Week 24: During the last few weeks your baby has grown to around 33cms, the eyelids are now separated allowing your baby to open & close it's eyes & the skin is covered in lanugo (fine hair) & is protected by a coating of vernix (a waxy secretion). The lips are also now distinct.

Week 28: Your baby's head & body are now more in proportion & is now around 37cm in length.

Week 32: By now you baby may have assumed the 'head down' position ready for birth & spends most of its time asleep.

Week 36:The baby is around 46cm in length. The lungs development rapidly over the next few weeks & if born now, has a great chance of survival.

Week 38: Your baby could be born any day now! It is thought that labour is triggered by your baby. It sends a message to your brain telling it to start the process.

Every baby develops differently & in utero is no different!. This fetal development page is designed to give a general idea of how a fetus grows in the womb. Consult your doctor or Health Clinic for any medical advice.