Picture and Explanation of How Your Baby is Growing and Developing at 28 Weeks Pregnant
By your 28th week of pregnancy, your baby is about 16 inches long
and weighs between two and three pounds. The skin is wrinkled but will become less
so as more subcutaneous fat, the layer of fat just under the skin, is
laid down in the next few weeks. Fine downy hair, called lanugo, and a
waxy white protective substance covering the skin, called vernix, are
present on the baby's body. The baby's eyes are open. The eyebrows and
eyelashes were formed in the fourth month. The baby sucks its thumb and
its taste buds have developed. The baby kicks, stretches, and moves
frequently in the uterus. These movements, which are readily observable
to others, are often keenly felt by the mother. Some mothers may find
that the pressure of the growing uterus against the stomach by this
week causes heartburn. The fundus, the top of the uterus, is now about
one-third of the distance between the umbilicus (bellybutton) and the
xiphoid cartilage. Constipation may also occur due to uterine pressure
on the lower colon, as well as hormonal slowing of peristalsis (the
process of excreting waste). Uterine growth combined with increased
maternal weight gain contribute to a recurrence of fatigue similar to
that during the early weeks of pregnancy.
By the 28th week, changes in the breasts prepare them for lactation.
First colostrum, then milk, is produced by the grape-like clusters of
tiny sacs (alveoli) deep within the breast tissue. Clusters of alveoli
form lobules, which consolidate to form 15 to 20 lobes. Each lobe
connects to a lactiferous duct. As the ducts extend toward the nipple
and areolar areas, they widen into the lactiferous sinuses. These
sinuses (or milk pools) release the milk through 15 to 20 tiny nipple
openings when the baby nurses.
The baby's organs and systems are quite well developed by the 28th week
of pregnancy. If born now, the baby would probably survive but would
need intensive, specialized care. The final two months of gestation are
important for further maturation of all body systems and organs. Full
term gestation best prepares the baby for a smooth and healthy
adjustment to life outside of your uterus.
Most recent page update: 6/4/2013
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Founded in 1918, Childbirth Connection has joined forces with and become a core program of the National Partnership for Women & Families. Together, these two women's health powerhouses are transforming maternity care in the United States.