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 uterus (womb), 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!
Conception
See what happens inside you during the conception process.One month pregnant
Your baby is an embryo consisting of two layers of cells from which all her organs and body parts will develop.Two months pregnant
Your baby is now about the size of a kidney bean and is constantly moving. He has distinct, slightly webbed fingers.Three months pregnant
By now your baby is around 7cm to 8cm long (as long as a pea pod) from crown to rump and weighs 23 grams (about half a banana).Four months pregnant
Your baby is now about 13cm long and weighs 140g. His skeleton is starting to harden from rubbery cartilage to bone.Five months pregnant
Eyebrows and eyelids are now in place. Your baby would now be more than 27cm long if you stretched out her legs.Six months pregnant
Your baby weighs about a 660g. His wrinkled skin is starting to smooth out as he puts on baby fat.Seven months pregnant
By now, your baby is more than 40cm long. She can open and close her eyes and probably see what's around her.Eight months pregnant
Your baby now weighs about 2.2kg. His layers of fat are filling him out, making him rounder, and his lungs are well developed.Nine months pregnant
Your baby is almost due. At birth, the average baby is more than 51cm long from head to toe, and weighs about 3.4kg, but babies vary widely in size at this stage.Month by month with ultrasound images
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
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