Weeks 13-16 – Gestational Age / Weeks 11-14 – Fetal Age
** Gestational age is the age of the pregnancy from the last normal menstrual period (LMP) and fetal age is the actual age of the growing baby.
The fetus's skin is transparent and a fine hair called lanugo begins to form on the head. The fetus begins sucking and swallows bits of amniotic fluid. Fingerprints which individualize each human being have now developed on the tiny fingers of the fetus. Meconium is made in the intestinal tract and will build up to be the babies first bowel movement. Flutters may be felt in the mom's growing abdomen as the fetus begins to move around more. Sweat glands have developed and the liver and pancreas produce fluid secretions. The fetus has reached 6 inches in length and weighs about 2 ½ oz.
Source: American Pregnancy Association