Weeks 33-36: The fetus reaches approximately 41-48 cm. (16-19 in.) in length and weighs 2.6-3.0 kg (5 lb. 12 oz. to 6 lb. 12 oz.). Body fat continues to increase, lanugo begins to disappear, and fingernails are fully grown.
Fine hair called lanugo first develops on the head; structures such as the lungs, sweat glands, muscles, and bones continue to develop.
Your baby will develop lanugo (fine body hair) and it will darken enough to be seen on an ultrasound.
Lanugo begins to cover all skin surfaces, and fat begins to develop under the skin.
The patient may feel chilly or have developed lanugo, a growth of downy body hair.
Lanugo has mostly disappeared and is replaced with thicker hair on the head.
Lanugo or fine body hair grows on your baby's skin during this trimester.