WK5B: Physiological Changes in Pregnancy

The Confirmation of Pregnancy

• A medical diagnosis of pregnancy serves to date when the birth will occur and helps predict the existence of a high-risk status

• Pregnancy was diagnosed on symptoms reported by a woman and the signs elicited by a health care provider

Signs and symptoms of Pregnancy

• 1. Presumptive Signs (Subjective Symptoms) - are findings in connection with the body system in which they occur and are experienced by the woman but cannot be documented by an examiner

  • a. Breast changes – feelings of tenderness, fullness, tingling, enlargement and darkening of areola

  • b. Nausea and vomiting – on arising or when fatigue

  • c. Amenorrhea – absence of menstruation

  • d. Frequent urination – sense of having to void more often than usual

  • e. Fatigue - general feeling of tiredness

  • f. Uterine enlargement – uterus can be palpated over symphysis pubis

  • g. Quickening - fetal movement felt by woman

  • h. Linea Nigra – line of dark pigment forms on the abdomen

  • i. Melasma – dark pigmentation forms on face

  • j. Striae Gravidarum) - red streaks forms on abdomen

• 2. Probable Signs (Objective Symptoms) – are findings and can verified by an examiner

  • Chadwick’s sign - color change of the vagina from pink to violet

  • Goodell’s sign – softening of the cervix

  • Hegar’s sign - softening of the lower uterine segment

  • Sonographic evidence of gestational sac

  • Braxton Hick’s contraction – periodic uterine tightening

  • Fetal outline felt by examiner through palpation

  • Ballottement – the fetus can feel through bimanual examination

  • Laboratory Tests – blood serum and urine specimen to detect the presence of human chorionic gonadotrophin (hCG)

    • a. Serum pregnancy test – hCG appear as early as 24 – 48 hrs. after implantation and reach a measurable level about 50 unit/ml 7-9 days after conception

    • b. Urine sample – concentrated such as a first urine in the morning

    • c. Home Pregnancy Test -it takes 2-3 mins. to complete and have a high degree of accuracy

    • d. Early prenatal care – is the best safeguard to ensure successful pregnancy.

• 3. Positive Signs of Pregnancy

  • a. Sonographic evidence of fetal outline. – fetal outline can be seen and measure by sonogram

  • b. Fetal movement felt by examiner

  • c. Fetal heart audible – doppler ultrasound reveal heartbeat (10th – 12th week of gestation

Physiologic Changes of Pregnancy

They can categorize as local (confined to the reproductive organs) or systemic (affecting the entire body)

• 1. Reproductive System Changes

  • a. Uterine Changes – increase the size of the uterus to accommodate the growing fetus. The uterus increases in length, depth, width, weight, wall thickness and volume

    • Length – from 6.5 - 32 cm;

    • Width – from 4cm to 24 cm;

    • Weight - increases from 50g to 1000g;

    • Depth- increases from 2.5 cm to 22 cm

    • Uterine wall thickens from 1cm to 2cms

    • Volume – increases from 2 ml. to more than1,000 ml. can hold a total of 4000g at term (7-lb (3.175 g.) fetus, 1,000 ml. amniotic fluid

    • Fundus height at various week of pregnancy

      • 20-22nd week – reaches the level of the umbilicus

      • 36th week – touches the xiphoid process

      • 38th week – fetal head settles into the pelvis

    • Hegar’s signs – extreme softening of the lower uterine segment

    • Ballottement – the fetus can be felt to bounce or rise in the amniotic fluid

    • Braxton Hick’s contraction

    • Amenorrhea

  • b. Cervical changes – becomes more vascular and edematous

    • Goodell’s sign - softening of the cervix

  • c. Vaginal Changes – increase vascularity of the vagina

    • Chadwick’s sign - changes in color from light pink to a deep violet

  • d. Ovarian Changes – active production of estrogen and progesterone

  • e. Breast changes

    • Feeling of fullness, tingling or tenderness because of increased estrogen level

    • Breast size increase because of the growth in mammary alveoli and in fat deposit

    • Areola of the nipple darkens and the diameter increases from about 3.5 cm (1.5 inches) to 5cm or 7 cm (2 or 3 inches)

• 2. Endocrine changes

  • ● Increased thyroid and parathyroid hormone production

  • ● Palmar erythema

  • ● Insulin production is decreased early during pregnancy and increases after the 1st trimester

  • ● Prolactin, Melanocyte-stimulating hormone, and human growth hormone of the pituitary gland increase,

  • ESTOGEN AND PROGESTERONE produced

  • ● Placenta as a transient endocrine organ

  • ● Colostrum can be expelled as early as 16 weeks

  • ● Increase vascularity

  • ● Enlarge and protuberant nipples

• 3. Respiratory system

  • ● Shortness of breathing is common

  • ● Marked congestion or stuffiness – due to increase estrogen

• 6.Cardiovascular system

  • ● 30-50% increase in the total cardiac volume

  • ● Physiologic Anemia of pregnancy may occur

  • ● Increases heart rate

  • ● Palpitations is common

  • ● Edema and varicosities of the lower extremities

• 7. Gastrointestinal system

  • ● Slow emptying time of the stomach

  • ● Nausea and vomiting

  • ● Decreased pH of the saliva

  • ● Hemorrhoids is common due to constipation, pressure of the uterus, slow peristalsis

• 8. Urinary System

  • ● Glomerular Filtration rate increases

  • ● BUN and Plasma Creatinine decreases

  • ● Renal threshold for sugar decreases

  • ● Frequent urination in 1st trimester, normalizes in 2nd trimester, frequent urination in 3rd trimester

• 9. Muscular system

  • ● Calcium and Phosphorus needs are increased

  • ● Gradual softening of the pelvic ligaments

  • ● Wide separation of the symphysis pubis

• 10. Immune system

  • ● IgG production decreases

  • ● WBC simultaneously increases