Week 4: Your fertilized egg is implanted in the wall of your uterus and the placenta and umbilical cord begin to form.
Week 6: The tiny embryo’s heart begins to pump blood and the neural tube that will become the spine closes. She takes on a C-shape and tiny little arm and leg buds begin to form.
Week 8: Brainwave activity starts. Webbed fingers and toes begin to form.
Week 9: Her heart is almost completely developed. Eyelids are forming along with hair follicles and nipples.
Week 10: The embryo is now officially a fetus. She will be doing occasional breathing movements, drawing oxygen through the umbilical cord.
Week 11: Nearly all her organs and body structures are formed and beginning to function. Genitals take on male or female form. Your fetus can now sigh, stretch, move her head and suck her thumb.
Week 12: at the end of your first trimester pregnancy stage your baby’s nose and lips are completely formed and she is starting to produce and excrete urine.
Week 13: This is the start of your second trimester pregnancy stage and your baby is starting to look more human.
Week 14: Baby’s nose, lips and taste buds are formed.
Week 16: Her eyes are starting to move slowly and she can frown.
Week 18: Teeth have started to form and baby can hear sounds in your body and may even get startled at loud noises.
Week 20: Sweat glands are forming and baby becomes coated in a white, creamy substance called vernix caseosa that protects her skin in the aqueous environment.
Week 22: Baby’s brain is entering a period of rapid growth.
Week 23: If it’s a boy, his testicles will begin to descend into the groin from the abdomen. If it’s a girl her uterus and ovaries will have developed.
Week 24: Baby will have established a waking and sleeping pattern. Real hair will start to grow on her scalp. If she was born now she’d have a 50% chance of survival.
Week 26: Her eyes are starting to open and her lungs are beginning to develop surfactant which allows them to inflate.
Week 28: You are now at the end of your second trimester pregnancy stage and your baby can taste and smell, her eyes can produce tears and her bones are all fully developed (although still quite soft). Weight gain will be rapid from this week on and her brain will increase up to 500% in weight between now and delivery.