Characteristics of the Unborn Child

14 – 16 Weeks Post-LMP
12 – 14 Weeks Post-Conception

By 15 weeks, the fetus, except for parts of the scalp, may respond to touch. Tooth development may begin.

At 16 weeks, a pregnant woman may begin to feel the fetus move.  Female fetuses may show more jaw movement than male fetuses.

The 16-week fetus weighs about 4 ounces and measures slightly less than 7 inches.


16 – 18 Weeks Post-LMP
14 – 16 Weeks Post-Conception

The fetus begins making several digestive enzymes.

Around 17 weeks blood cell formation moves to its permanent location inside the bone marrow and the fetus begins storing energy in the form of body fat.

By 18 weeks, the fetus produces many of the same hormones found in adults, including a hormonal stress response.

The 18-week fetus weighs around 6 ounces and measures about 8 inches.

18 – 20 Weeks Post-LMP
16 – 18 Weeks Post-Conception

The formation of the breathing passages, called the bronchial tree, is complete.

By 20 weeks the larynx or voice box may show movement similar to  crying after birth.
The skin has developed sweat glands and is covered by a greasy white substance called “vernix,” which provides protection from the amniotic fluid.

By 20 weeks gestation, the unborn child has the physical structures necessary to experience pain.  There is evidence that by 20 weeks gestation fetuses seek to evade certain stimuli in a manner which in an infant or an adult would be interpreted to be a response to pain.  Anesthesia is routinely administered to fetuses who are 20 weeks gestational age or older who undergo prenatal surgery ” (Title 63 O.S. § 1-738.10).

The 20-week the fetus weighs about 9 ounces and measures about 10 inches.

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