Pregnancy; symptoms, signs and diagnosis

Obstetrics – Dr. Maryam - Lecture 1                      Oct.12th 2011

              Pregnancy; symptoms, signs and diagnosis
Pregnancy is a physiological state, but the importance of the diagnosis cannot be
overstated. Knowledge of the existence of pregnancy is crucial to the proper
diagnosis and treatment of all disease processes.

Every physician who takes responsibility for the medical care of women of
reproductive age, irrespective of the nature of the physician’s special interest,
must always consider the question: Is she pregnant?

Symptoms of pregnancy:
The endocrinological, physiological, and anatomical changes that occur in
pregnancy give rise to symptoms and signs that provide evidence that pregnancy
exist. These symptoms include:

   1- Cessation of menses (amenorrhea): although amenorrhea is an early and
      important indication of pregnancy, but it’s not reliable in women with
      irregular cycle, on the other hand conception may occur without prior
      menstruation such as in lactation-induced amenorrhea.

   2- Change in the breast: these changes are quite characteristic in
      primiparas(1st pregnancy) and less obvious in multiparas..pain in the breast
      range from tingling sensation up to marked pain and tenderness, these are
      begin as the rising estrogen levels promotes mammary growth and
      development of the ductal system; progesterone stimulates the alveolar
      system as well as the mammary growth.

      The areola and nipples enlarge and darken in pigmentation. Because of
      increased vascularity, the breast appears shiny blue with dilated vein.
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The enlargement of sebaceous gland of areola is named Montgomery’s
      tubercle commonly occurs at 6-8 weeks of gestation and its due to
      hormonal effect. Colostrums secretion may start from 16 weeks

   3- Nausea with or without vomiting: pregnancy is commonly characterized by
      disturbances of the GIT system, manifested mainly by nausea and vomiting.
      This so called morning sickness is mainly occur in morning but could occur
      at any time and it’s more marked between 6-12 weeks.

   4- Disturbance in urination: during the first trimester this may be due to
      pressure exerted by enlarging uterus and increased bladder vascularity. As
      pregnancy progresses, the frequency of urination gradually decrease as
      uterus enlarge to become an abdominal organ. The symptom of frequent
      urination reappears near the end of pregnancy, however, when the fetal
      head descends into the maternal pelvis. Urinary tract infection should
      always be excluded because it’s very common during pregnancy.

   5- Perception of fetal movement (Quickening): the first time that the mother
      feel fetal movement is called quickening, this will usually be between 18-20
      weeks in primagravida, and 2 week earlier (16-18weeks) in multigravida.

Signs of pregnancy:
There are a number of clinical signs that frequently herald pregnancy.

   1- If the rise of temperature during luteal phase of cycle is followed up there
      will be persistence of this rise in first three weeks of pregnancy due to
      thermogenic effects of progesterone.

   2- Changes in skin: many women experience skin changes during pregnancy
      that may spontaneously resolve after the pregnancy.
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a- Chloasma, known as the “mask of pregnancy” which is a butterfly-
      shaped pigmentation over the forehead, bridge of the nose or cheek
      bones, more prominent in dark skinned females and intensified by
      sunlight exposure.

   b- Lina nigra, the faint brown hyper pigmented line that begins at the
      sterna notch and extends down the abdomen through the umbilicus to
      the pubis.

      The above tow mentioned skin change is due to increased stimulation of
      the melanophores by an increase in melanocyte-stimulating hormone in
      pregnancy.

   c- The striae, or stretch marks, in area of weight gain, particularly on the
      abdomen and breasts and sometimes over the thigh., and these are
      caused by the separation of the underlying collagen fibers and its
      probably an adrenocorticosteroid response. These marks appear late in
      pregnancy(when skin tension increase) as an irregular scars bright red at
      first but they will shrink and lighten to silvery white.

   d- Vascular changes in skin, in the form of palmer erythema and spider
      telangiectases (minute red elevation on the skin mainly over face ,neck,
      upper chest and arm) are of no clinical significant and due to
      hyperestrogenisim.

3- Enlargement of the abdomen: progressive abdominal enlargement occurs
   throughout pregnancy and this is more rapid at 16-22 weeks when the
   uterus becomes an abdominal organ. By 12 weeks, the uterus is palpable
   through the abdominal wall just above the symphysis pubis, there after the
   uterus gradually increase in size until the end of pregnancy.

4- BRAXTON HICKS CONTRACTION these are refers to palpable but painless
   contraction that occurs when the uterus enlarged and rotates to the right

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axis and felt as tightening that usually begins at 28 weeks of pregnancy and
   improve by walking.

5- Ballottement: at mid pregnancy (20 weeks), the volume of the fetus is small
   compared to that of amniotic fluid. Consequently, sudden pressure exerted
   on the uterus may cause the fetus sink in amniotic fluid and rebound to its
   original position, the tap produced (ballottement) is felyt on bimanual
   examination.

6- Uterine soufflé: these are a rushing sound synchronous with maternal puls
   felt after 16 weeks by auscultation of the abdomen and is caused by
   movement of maternal blood filling the placental vessels and sinuses.

7- Changes due to pelvic organ:

   a- Hegar’ s sign this occurs at 6 to 8 weeks due to increase in width of
      softened isthmus which is sometime so marked that makes the cervix
      and body of uterus seem to be separate organs.

   b- Goodell’ s sign; this seen as early as 4 weeks and its cyanosis and
      softening of cervix due to increased vascularity of cervical tissue

   c- Excessive vaginal discharge or Leukorrhea; this consist of epithelial cells
      and cervical tissue.

   d- Chadwick‘s sign; purplish or bluish discoloration of vagina and cervix due
      to pelvic congestion.

   Positive evidence of pregnancy:
   All the above mentioned symptoms and sign of pregnancy are often reliable
   but not diagnostic because as we mentioned previously these
   manifestation may mimic many disease process or physiological processes,
   so we need other reliable methods to make diagnosis more accurate.

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1- Identification of fetal heart: hearing or observing the pulsation of the
   fetal heart assures the diagnosis of pregnancy.

   The fetal heartbeat can be detected by auscultation with a fetoscope by
   17 weeks, on average, and by 19 weeks in nearly all pregnancies in non-
   obese women. The normal fetal heart rate ranges from 110-160 beats
   per minutes (bpm) and is heard as a double sound resembling the tick of
   a watch under a pillow. It’s not sufficient merely to hear the fetal heart
   but its also important to compare with maternal pulse.

   Doppler ultrasound can detect fetal heart as early as 10 weeks.

2- Palpation of fetal parts: from 22 weeks on ward the fetal part can be
   the fetal parts can be palpated through the maternal abdomen by the
   examiner. Fetal movement can also be both palpable and visible
   through abdominal wall especially in thin person.

3- Ultrasonic recognition of pregnancy:

   The most useful way for diagnosis of pregnancy is by sonography. The
   use of transvaginal sonography has revolutionized imaging of early
   pregnancy and its growth and development.

   - By 35 days, all normal sacs should be visible.

   - By 5-6 weeks the fetal heartbeats should detectable.

   - By 7-8 weeks limb buds can be detected.

   - By 9-10 weeks finger and limb movement are seen.

   - By 10 weeks after LMP, that is at the end of embryonic period the
     embryo has the appearance of human.

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4- Radiology (X-ray) : X-ray should be avoided during pregnancy because of
   potential teratogenic and oncogenic effect on the fetus. However, the
   benefit outweighs the risk and it may be used. Up to 10 rads is
   considered safe during pregnancy.

   The ossification center appears at 12-14 weeks.

   Pregnancy tests:
   The bases for pregnancy test PT is detection of human chorionic
   gonadotropin hCG, which is glycoprotein that produced by the
   syncytiotrophoblast 8 days after fertilization and may be detected in the
   maternal serum 1 day later. The half life of hCG is about 1.5 days. This
   hormone can be detected in body fluids by any one of variety of
   immunoassay or bioassay techniques.

   The hCG level peaks approximately 65 days after conception and
   gradually decrease in the second and third trimester and slightly
   increase after 34 weeks, normally serum and urine hCG levels return to
   non pregnant values that is less than 5mIU/ml 21-24 days after delivery.

   Types of immunologic tests:

   1- Immunologic tests: These tests are based on antigenic properties of
      hCG and it take about 2minut-2hours. The available testes are direct
      and indirect agglutination of sensitized red blood cell or latex
      particles. Sensitivities vary from 250-3500mIU/ml, depending on the
      product used. Most are positive by 5-7 days after the first missed
      period.

   2- Radioimmunoassay: this is sensitive and specific test for early
      pregnancy and can detect serum levels as low as 2-4mIU/ml. the

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reagent used is specific to the beta-subunit of HCG but it requires 24-
              48 hours of incubation time.

              Titration or quantitative assay of hCG can be used to determine
              normality and viability of early pregnancy.

           3- Radioimmunoassay: this measures receptor sites by competitive
              binding mechanism and it can detect levels of 200mIU/ml. It also
              cross- react with LH.

           4- Home pregnancy tests: these are immunologic tests that can be done
              at home it detect hCG in first-voided morning urine sample, a
              positive pregnancy test is indicated by color change or conformation
              mark in the test paper. The negative test should be repeated 2 weeks
              later.

Duration of normal human pregnancy:
Normally human pregnancy lasts 280 days or 40 weeks from the last normal
menstrual period (LMP), and as 266 days or 38 weeks from the last ovulation in
normal 28 days cycle.

The EDD:

The expected date of delivery is the probable date of birth and is calculated using
Nagaele’s rule and this is by subtracting 3 months from the month of LMP and
adding 7 days to the first day of LMP.

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