Fetal development week by week

Follow your baby's development from a tiny mass of cells through to a fully developed baby. Our illustrations show how your baby is growing inside your womb (uterus), while our Inside pregnancy videos take a 3D animated look at a baby from conception to labour and birth. And see the whole nine months in one timeline!

One month pregnant

Fetal development diagram - one month
Your baby is an embryo consisting of two layers of cells from which all her organs and body parts will develop.

Two months pregnant

Fetal development diagram - two months
Your baby is now about the size of a kidney bean and is constantly moving. He has distinct, slightly webbed fingers.

Three months pregnant

Fetal development diagram - three months
By now your baby is around 7 to 8 centimeters (3 inches) long and weighs about the same as a pea pod. Her tiny, unique fingerprints are now in place.

Four months pregnant

Fetal development diagram - four months
Your baby is now about 13cm (5.5in) long and weighs 140g (5oz). His skeleton is starting to harden from rubbery cartilage to bone.

Five months pregnant

Fetal development diagram - five months
Eyebrows and eyelids are now in place. Your baby would now be more than 27cm (10.5in) long if you stretched out her legs.

Six months pregnant

Fetal development diagram - six months
Your baby weighs about a 660g (1.5lb). His wrinkled skin is starting to smooth out as he puts on baby fat.

Seven months pregnant

Fetal development diagram - seven months
By now, your baby is more than 40cm (15in) long. She can open and close her eyes and probably see what's around her.

Eight months pregnant

Fetal development diagram - eight months
Your baby now weighs about 2.2kg (4.7lb). His layers of fat are filling him out, making him rounder, and his lungs are well developed.

Nine months pregnant

Fetal development diagram - nine months
Your baby is almost due. At birth, the average baby is more than 51cm (20.5in) long from head to toe and weighs approximately 3.4kg (7.5lb), but babies vary widely in size at this stage.

Month by month with ultrasound images

ultrasound scan
See our summary of how your baby is developing from two months. Within each month, 3D ultrasound images give you an idea of how your baby may look.


Images by BabyCenter

Track your baby’s development

Join now to receive free weekly newsletters tracking your baby’s development and yours throughout your pregnancy.
Trying to conceive?
I agree to receive relevant emails from BabyCentre and to the use of my health information to make the service more helpful.
Yes! Please email me with free offers and special discounts from BabyCentre’s partners.
By clicking the button, you agree to our Terms of Use and Privacy Policy.
advertisement
Join BabyCentre
Sign up to receive free emails and track your baby's development.