M4

• Ovulation


  Stops with pregnancy because of the active feed-back mechanism of estrogen and progesterone
• Corpus luteum


  Increases in size on the surface of the ovary until about the 16th week of pregnancy, then regresses in size and appears white and fibrous
• Vagina


  • Epithelium and underlying tissue become hypertrophic and enriched with glycogen
  • Structures loosen from their connective tissue attachments in preparation for great distention at birth
  • Increased vascularity changes the color of the vaginal walls from the normal light pink to a deep violet (Chadwick's sign)
  • Secretions during pregnancy fall from a pH of greater than 7 to 4 or 5 due to the action of Lactobacillus acidophilus
• Cervix


  • Becomes more vascular and edematous
  • Softens in consistency
  • Glands of the endocervix undergo hypertrophy and hyperplasia
  • Filled with a tenacious coating of mucus (the operculum) that seals out bacteria
• Uterus


  • Increases in length, depth, width, weight, wall thickness, and volume
  • Early in pregnancy the wall thickens from about 1 cm to about 2 cm, then thins to about 0.5 cm thick at the end
  • Volume increases from about 2 mL to more than 1000 mL
  • Can hold a 7-lb fetus plus 1000 mL of amniotic fluid
• Lightening


  The fetal head settling into the pelvis 2 weeks before term, making breathing easier
• Hegar's sign


  Extreme softening of the lower uterine segment, felt as thin as tissue paper on bimanual examination
• Ballottement

  Fetus bouncing or rising in the amniotic fluid when the lower uterine segment is tapped sharply
• Braxton Hicks contractions

  Uterine contractions that serve as warm-up exercises for labor and increase placental perfusion
• Breasts


  • Increase in size due to hyperplasia of mammary alveoli and fat deposits
  • Areola darkens and increases in diameter
  • Secondary areola may form
  • Veins become prominent
  • Montgomery's tubercles enlarge
  • Produce colostrum by 16th week
• Respiratory system


  • Nasopharynx becomes congested
  • Diaphragm displaced upward by enlarging uterus, reducing residual volume but increasing tidal volume and total oxygen consumption
  • Mild hyperventilation leads to respiratory alkalosis and compensatory increased urination
• Cardiovascular system


  • Cardiac output increases 25-50%
  • Heart shifts to a more transverse position, may cause functional murmurs
  • Palpitations early from sympathetic stimulation, later from thoracic pressure
  • Pulmonary and peripheral vascular resistance decreases, lowering blood pressure in first/second trimesters
  • Blood flow to lower extremities impaired, leading to edema and varicosities
  • Supine hypotensive syndrome from uterine compression of vena cava
  • Blood volume increases, leading to pseudo-anemia early on
• Renal system


  • Urinary frequency early, relieved in second trimester, returns in third trimester
  • Urinary output increases by 60-80%
  • Glomerular filtration rate and renal plasma flow begin to increase
• Hemoglobin concentration


  Less than 11 g/100 mL or hematocrit value below 33% in the first or third trimester of pregnancy or hemoglobin concentration of less than 10.5 g/dL (hematocrit 32%) in the second trimester
• A woman's body compensates for the decline in hemoglobin and erythrocytes early in pregnancy by producing more red blood cells, creating near normal levels of red blood cells again by the second trimester
• True anemia


  Condition requiring iron therapy above normal supplementation
• Changes in the renal system during pregnancy

  1. Urinary frequency in first trimester

  2. Urinary frequency relieved in second trimester

  3. Urinary output gradually increases by 60-80%

  4. Specific gravity of urine decreases

  5. Glomerular filtration rate and renal plasma flow increase in early pregnancy

  6. GFR and renal plasma flow increase by 30-50% by second trimester
• The rise in GFR and renal plasma flow is consistent with the increase in the circulatory system, peaking at about 24 weeks
• The efficient GFR level leads to a lowered blood urea nitrogen and low creatinine levels in maternal plasma
• Changes in the integumentary system during pregnancy

  1. Abdominal wall stretching causes rupture and atrophy of connective layer, leading to striae gravidarum

  2. Striae gravidarum lighten to striae albicantes after birth

  3. Rectus muscles separate, causing diastasis

  4. Umbilicus becomes obliterated and protrudes

  5. Linea nigra forms

  6. Melasma (chloasma) appears on face

  7. Vascular spiders or telangiectases appear

  8. Sweat gland activity increases

  9. Palmar erythema may occur

  10. Scalp hair growth increases
• Striae gravidarum


  • Pink or reddish streaks appearing on the sides of the abdominal wall and sometimes on the thighs
• Striae albicantes


  Silvery-white color of striae gravidarum after birth
• Diastasis


  Separation of the rectus muscles due to difficulty of the abdominal wall stretching to accommodate the growing fetus
• Linea nigra


  Narrow, brown line running from the umbilicus to the symphysis pubis
• Melasma (chloasma)


  Darkened areas appearing on the face, particularly on the cheeks and across the nose
• Vascular spiders or telangiectases

  Small, fiery-red branching spots on the skin
• Palmar erythema


  Redness and itching on the hands
• Changes in the musculoskeletal system during pregnancy

  1. Relaxation of pelvic joints causes "waddling" gait

  2. Physiologic lordosis develops to compensate for weight of gravid uterus

  3. Softening of pelvic ligaments and joints to facilitate passage of baby

  4. Excessive joint mobility can cause discomfort

  5. Wide separation of symphysis pubis may occur
• Relaxin

  Ovarian hormone that contributes to softening of pelvic ligaments and joints
• Progesterone


  Placental hormone that contributes to softening of pelvic ligaments and joints
• Few neurological changes with a typical pregnancy, except for possible pressure on the sciatic nerve later in pregnancy due to fetal position
• Changes in the gastrointestinal system during pregnancy

  1. Muscles in GI system relax and food movement slows

  2. hCG increase causes nausea and vomiting (morning sickness) in first trimester

  3. Acidity of stomach secretions decreases, but heartburn may result from reflux

  4. Pressure from uterus slows intestinal peristalsis and stomach emptying, leading to heartburn, constipation, and flatulence

  5. Increased tendency for gallstone formation

  6. Pressure on veins can lead to hemorrhoids

  7. Gum hypertrophy and bleeding

  8. Increased saliva formation (hyperptyalism)
• Relaxin


  Enzyme produced by the ovary that contributes to decreased gastric motility
• Progesterone


  Hormone that has an effect on smooth muscle, making the gastrointestinal tract less active
• Changes in the endocrine system during pregnancy


  1. FSH and LH greatly decreased due to increased estrogen and progesterone from placenta

  2. Increased production of growth hormone and melanocyte-stimulating hormone

  3. Posterior pituitary begins producing oxytocin late in pregnancy

  4. Prolactin production begins late in pregnancy

  5. Thyroid gland enlarges and basal metabolic rate increases

  6. Parathyroid glands increase in size

  7. Adrenal gland activity increases, producing more corticosteroids and aldosterone

  8. Pancreas increases insulin production
• Ambivalence


  Feeling both pleased and not pleased about the pregnancy
• Psychosocial changes in the first trimester

  1. Accepting the reality of the pregnancy

  2. Receiving confirmation of pregnancy makes the mother feel "more pregnant"

  3. Uncertainty of symptoms can lead to denial

  4. Ambivalence is a common reaction, with both positive and negative feelings

  5. Partners may also experience ambivalence, sometimes more so than the pregnant woman
• Psychosocial changes in the second trimester


  1. Accepting that she is having a baby

  2. Feeling fetal movement (quickening) leads to the fetus assuming a separate identity

  3. Imagining herself as a mother and anticipatory role-playing

  4. Partner may feel left out and become preoccupied with work
• Psychosocial changes in the third trimester

  1. Preparing for the baby's arrival, such as planning sleeping arrangements, buying clothes, choosing a name

  2. Attending prenatal/childbirth classes

  3. Partner may experience physical symptoms like nausea, vomiting, and backache (couvade syndrome)
• Gravida

  Number of times a woman has been pregnant, including the current pregnancy