Maternal adaptation to pregnancy Flashcards
(27 cards)
Give 5 common symptoms of pregnancy.
- Amenorrhea
- Morning sickness, rarely lasts beyond 3rd month
- Constipation
- Fatigue
- Distention of the abdomen
- Increased frequency of micturition
- Breast discomfort and changes
What the following signs:
Chadwick’s sign
Goodell’s sign
Hegar’s sign
Ladin’s sign
Chadwick’s sign - dusky blue color of the anterior vaginal wall visible at about 8 weeks of pregnancy. Local vascularity
Goodell’s sign - Softening of cervix
Hegar’s sign – softening of the uterine isthmus between 4-6 weeks
Ladin’s sign – softening midline of uterus anteriorly at junction of uterus and cervix > 6 weeks GA
How does the uterus change during pregnancy?
- Uterine enlargement
- Stretching and hypertrophy of muscle cells( accumulation of fibrous tissue and elastic tissue)
How does the cervix change during pregnancy?
- Softening and cyanosis (1 month in)
- Proliferation of glands (hypertrophy and hyperplasia)
- Formation of mucous plug (operculum)
How does the vulva and vagina change during pregnancy?
Vulva
Becomes vascular and hypertrophied.
Superficial varicosities may be visible.
Labia minora pigmented and hypertrophied.
Vagina
Copious secretions
pH becomes acidic (3.5-6) due to lactic acid production
What is Jacquemier’s sign?
Bluish coloration of the mucosa (Jacquemier’s sign) due to increased blood supply in the venous plexus surround the vaginal wall
What happens to the breasts during pregnancy?
- Increase in size, nodularity and sensitivity throughout pregnancy.
- Enlargement due to alveolar proliferation and fat deposition.
- Total weight 0.4kg
- Nipples enlarge, become dark, erect.
- Enlargement of glands of Montgomery tubercles
How does pregnancy affect tidal volume, lung capacity, and gas exchange?
Tidal volume (TV) increases by 30–40%.
Total lung capacity (TLC) decreases by ~5% (due to diaphragm elevation).
Expiratory reserve volume decreases by ~20%.
Minute ventilation increases by 30–40% (TV ↑, respiratory rate constant).
Alveolar (PAO₂) and arterial (PaO₂) oxygen levels increase.
Alveolar (PACO₂) and arterial (PaCO₂) carbon dioxide levels decrease
How does cardiac output (CO) change during pregnancy?
Cardiac output increases by 30%–50%.
About 10% of CO is directed to the fetal-placental unit by the 10th week.
What causes the increase in preload and stroke volume during pregnancy?
Rising estrogen stimulates fluid reabsorption by the kidneys.
This increases vascular volume → increases preload.
Increased preload stretches the ventricles → increases stroke volume.
How is increased cardiac output maintained later in pregnancy?
Initially driven by increased stroke volume.
Later maintained by increased heart rate (HR).
HR increases by ~14% (about 10 beats/min).
HR does not exceed 100 bpm.
Define Supine Hypotensive Syndrome.
Supine Postural Syndrome (also called Supine Hypotensive Syndrome) is a condition that can occur in late pregnancy, typically after 20 weeks gestation, due to compression of the inferior vena cava (IVC) by the gravid uterus when a pregnant woman lies flat on her back.
How does pregnancy affect coagulation factors and fibrinolysis?
Pregnancy induces a hypercoagulable state.
Fibrinogen increases by 50%.
Coagulation factors VII, VIII, IX, X, and XII are elevated.
Fibrinolytic activity is decreased.
What other factors contribute to the hypercoagulable state in pregnancy?
Increased venous stasis.
Vessel endothelial damage.
Prothrombin time (PT) and activated partial thromboplastin time (APTT) are shortened.
Overall increased risk of thromboembolic events (PE and DVT)
How does pregnancy affect renal function?
Progesterone causes vasodilation of afferent arterioles → ↑ renal blood flow → ↑ GFR.
GFR increases by ~50% early in pregnancy and remains elevated.
Blood urea nitrogen (BUN) and creatinine decrease by ~25%.
Kidneys increase in size; ureters dilate → ↑ risk of pyelonephritis
What structural and urinary changes occur in the urinary tract during pregnancy?
Uterus increases bladder pressure → hydronephrosis and hydroureter.
Increased frequency of micturition.
Stress incontinence may occur.
Urinary stasis favors infection.
How does fluid retention come about in pregnancy?
Estrogen stimulates release of renin and angiotensin II, which in turn leads to an increase in aldosterone production, aldosterone promotes the water and sodium reabsorption.
How does pregnancy affect thyroid hormones?
Estrogen and progesterone levels increase throughout pregnancy.
Estrogen (from the placenta) increases hepatic production of thyroid-binding globulin (TBG).
More free T3 and T4 bind to TBG → stimulates more TSH release.
Free T3 and T4 remain unchanged, but total T3 and T4 increase.
Thyroxin is essential for fetal neural development.
How do hormonal changes during pregnancy affect glucose metabolism?
Human placental lactogen (hPL), prolactin, and cortisol levels rise (especially in 2nd trimester).
These are anti-insulin hormones → increase maternal insulin resistance.
Decreased peripheral glucose uptake in mother.
Ensures a continuous glucose supply for the fetus.
How is the maternal immune system modulated during pregnancy?
Pregnancy involves immune adaptation, not suppression.
Fetal-maternal cell exchange occurs.
~30% develop IgG to fetal HLA (unclear significance).
Fewer cytotoxic (CD8) T cells → immune tolerance.
No maternal immune attack on fetus.
What causes nausea and vomiting in early pregnancy?
Nausea and vomiting affect >70% of pregnancies, known as morning sickness.
Typically resolves by 14–16 weeks gestation.
Stomach displacement ↑ intra-gastric pressure → causes heartburn, nausea, and vomiting.
How does progesterone affect the gastrointestinal system during pregnancy?
Progesterone relaxes smooth muscles.
Gastric emptying and intestinal transit time are slowed.
More time for nutrient absorption, but causes constipation.
Constipation leads to hemorrhoids due to increased intra-abdominal pressure.
What are some other oral changes during pregnancy?
Gums may become soft and bleed easily.
Epulis (focal, soft, highly vascular swelling) can develop.
Define hyperemesis gravidarum.
Hyperemesis gravidarum refers to a severe form of morning sickness associated with weight loss (≥5% of pre-pregnancy weight) and ketosis.
