FETAL DEVELOPMENT

* Age is measured from fertilization, not from the woman’s last menstrual period (LMP). LMP generally adds 2 weeks to age from fertilization.

Conception

When egg and sperm combine, a unique and unrepeatable human being is created. At this moment, the DNA is already complete and characteristics such as sex, ethnicity, hair color, and eye color have all been determined.

4 Weeks [6 Weeks LMP]

By this point, the baby’s heart has already started beating, the foundations for the brain, spinal cord, and nervous system are laid, and the lungs begin to form.

8 Weeks [10 Weeks LMP]

The baby is now about the size of a thumb. Every organ is present, and brain activity can be recorded. The baby can perform actions like hiccupping, frowning, squinting, furrowing the brow, pursing the lips, moving arms and legs, turning the head, touching the face, breathing (without air), stretching, opening the mouth, yawning, and sucking.

12 Weeks [14 Weeks LMP]

The child’s sex can be observed via ultrasound, fingerprints and fingernails begin to develop, vocal cords and taste buds form, and the baby can make complex facial expressions and even smile.

16 Weeks [18 Weeks LMP]

The mother can now feel the baby’s movements. Nostrils and toenails become visible, and the baby can suck their thumb, do somersaults, and has a firm grip.

20 Weeks [22 Weeks LMP]

Ultrasounds can show speaking movements, and each side of the brain has a billion nerve cells now.

24 Weeks [26 Weeks LMP]

It is possible for babies this age to survive outside the womb with specialized medical treatment.

28 Weeks [30 Weeks LMP]

The baby is sleeping and waking at regular intervals, begins dreaming, and can recognize the mother’s voice.

32 Weeks [34 Weeks LMP]

The skin smooths, the pupils respond to light, the fingernails reach the tips of the fingers, and the baby is really getting cramped now.

36 Weeks [38 Weeks LMP]

The child is born an average of 264-270 days after conception and typically weighs 6 - 9 pounds and is 18 - 21 inches long.

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