LESSON 5
PHYSIOLOGIC CHANGES DURING PREGNANCY
5-1.
GENERAL
The changes that occur in the pregnant patient's body are caused by several
factors. Many of these changes are the result of hormonal influence, some are caused
by the growth of the fetus inside the uterus, and some are the result of the patient's
physical adaptation to the changes that are occurring. This lesson is closely related to
anatomy and physiology.
5-2.
CHANGES OF THE REPRODUCTIVE SYSTEM DURING PREGNANCY
Changes in the body during pregnancy are most obvious in the organs of the
reproductive system.
a. Uterus.
(1) Changes in the uterus are phenomenal. By the time the pregnancy has
reached term, the uterus will have increased five times its normal size:
(a) In length from 6.5 to 32 cm.
(b)
In depth from 2.5 to 22 cm.
(c)
In width from 4 to 24 cm.
(d) In weight from 50 to 1000 grams.
(e) In thickness of the walls from 1 to 0.5 cm.
(2) The capacity of the uterus must expand to normally accommodate a
seven-pound fetus and the placenta, the umbilical cord, 500 ml to 1000 ml of amniotic
fluid, and the fetal membranes.
(3) The abdominal contents are displaced to the sides as the uterus grows
in size, which allows for ample space for the uterus within the abdominal cavity.
(a) Growth of the uterus occurs at a steady, predictable pace.
(b) Measurement of the fundal height during pregnancy is an important
factor that is noted and recorded (see figure 5-1).
MD0921
5-2