Serve as a source of oral fluid for the fetus.
Act as an excretion and collection system.
b. Chorion. This is the outer membrane. It forms a large portion of the
connective tissue thickness of the placenta on its fetal side. It is the structure in and
through which the major branching umbilical vessels travel on the surface of the
FETAL GROWTH AND DEVELOPMENT
Growth refers to an increase in size. Development is the continuous process by
which an individual changes from one life phase to another. These phases includes the
prenatal period and the postnatal period. Fetal maturation takes place in an orderly and
predictable pattern. The physicians refer to the age of a pregnancy as lunar months.
The lunar months corresponds to the usual length of the menstrual cycle, in this
respect, it is easier to calculate. A lunar month is a period of four weeks (28 days) and
a trimester is a time period of 3 months.
a. First Trimester. During the first three months of pregnancy, the product of
conception grows from the just-visible speck to the fertilized ovum to a lively embryo. At
the end of the first trimester, the following changes have or are occurring:
All organs are formed.
(2) The fetus becomes less vulnerable to the effects of most drugs, most
Facial features are forming and the fetus becomes human in
External sex organs are visible, but positive sex identification is difficult.
Well-defined neck, nail beds beginning, and tooth buds form.
Rudimentary kidneys excrete small amounts of urine into the amniotic
There is movement but just not strong enough to be felt.
The fetus is about 2.9 inches long and weighs about 14 grams.
b. Second Trimester. During these months (4th, 5th, and 6th) the fetus grows
fast. At the end of the second trimester, the fetus:
Fetal heart tone (FHT) can be heard with a stethoscope.