3-5. PROBABLE SIGNS
Probable signs of pregnancy are those signs commonly noted by
the physician upon examination of the patient. These signs include uterine
changes, abdominal changes, cervical changes, basal body temperature, positive
pregnancy test by physician, and fetal palpation.
a. Uterine Changes.
(1) Position. By the twelfth week, the uterus rises above the
symphysis pubis and it should reach the xiphoid process by the 36th week of
pregnancy. These guidelines are fairly accurate only as long as pregnancy is
normal and there are no twins, tumors, or excessive amniotic fluid.
This corresponds to changes that occur in the uterus, as the uterus grows the
abdomen gets larger. Abdominal enlargement alone is not a sign of pregnancy.
Enlargement may be due to uterine or ovarian tumors, or edema. Striae
gravidarum may also be classified as a probable sign of pregnancy by the
(2) Size. The uterine increases in width and length
approximately five times its normal size. Its weight increases from 50 grams
to 1,000 grams.
(3) Hegar's sign. This is softening of the lower uterine
segment just above the cervix. When the uterine is compressed between
examining fingers, the wall feels tissue paper thin. The physician will use
bimanual maneuver simultaneously (abdominal and vaginal) and will cause the
uterus to tilt forward (see figure 3-1). The Hegar's sign is noted by the
sixth to eighth week of pregnancy.
(4) Ballottement. This is demonstrated during the bimanual
exam at the 16th to 20th week. Ballottement is when the lower uterine segment
or the cervix is tapped by the examiner's finger and left there, the fetus
floats upward, then sinks back and a gentle tap is felt on the finger (see
figure 3-2). This is not considered diagnostic because it can be elicited in
the presence of ascites or ovarian cysts.
c. Cervical Changes.
(1) Goodell's sign. The cervix is normally firm like the
cartilage at the end of the nose. The Goodell's sign is when there is marked
softening of the cervix. This is present at 6 weeks of pregnancy.
(2) Formation of a mucous plug. This is due to hyperplasia of
the cervical glands as a result of increased hormones. It serves to seal the
cervix of the pregnant uterus and to protect it from contamination by bacteria
in the vagina (see figure 3-3). The mucous is expelled at the end of pregnancy
near or at the onset of labor.
(3) Braxton-Hick's contractions. This involves painless
uterine contractions occurring throughout pregnancy. It usually begins about
the 12th week of pregnancy and becomes progressively stronger. These
contractions will, generally, cease with walking or other forms of exercise.
The Braxton-Hick's contractions are distinct from contractions of true labor
by the fact that they do not cause the cervix to dilate and can usually be
stopped by walking.
d. Basal Body Temperature.
This is a good indication if the patient has been recording for several cycles
previously. A persistent temperature elevation spanning over 3 weeks since
ovulation is noted. Basal body temperature (BBT) is 97 percent accurate.
e. Positive Pregnancy Test by the
Physician. This may be misread by doing it too early
or too late. Even if the test is positive, it could be the result of ectopic
pregnancy or a hydatidiform mole (an abnormal growth of a fertilized ovum) (see
f. Fetal Palpation.
This is a probable sign in early pregnancy. The physician can palpate the
abdomen and identify fetal parts. It is not always accurate,
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