Physiological Changes During Pregnancy

Vocabulary practice flashcards covering cardiovascular, hematologic, respiratory, renal, endocrine, metabolic, and anatomical physiological adaptations during pregnancy.

Physiological changes of pregnancy

The normal adaptations that a woman undergoes during pregnancy to better accommodate the embryo or fetus, involving the cardiovascular, hematologic, metabolic, renal, and respiratory systems.

Estrogen (during pregnancy)

A steroid hormone mainly produced by the placenta that is associated with fetal well-being.

Human chorionic gonadotropin ($\beta\text{-hCG}$)

A hormone produced by the placenta that maintains progesterone production by the corpus luteum during early pregnancy.

Progesterone (during pregnancy)

A hormone produced first by the corpus luteum and later by the placenta that relaxes smooth muscle and increases minute ventilation to $50\%$ greater than non-pregnant levels.

Prolactin (during pregnancy)

An anterior pituitary hormone that increases due to a $50\%$ maternal pituitary gland enlargement, mediating the structural change in the mammary gland from ductal to lobular-alveolar.

Human placental lactogen (hPL)

A placental hormone that stimulates maternal lipolysis and fatty acid metabolism to conserve glucose for fetal use, and decreases maternal insulin sensitivity, potentially leading to gestational diabetes.

Parathyroid hormone (during pregnancy)

A hormone that increases during pregnancy to elevate calcium uptake in the gut and promote calcium reabsorption by the kidneys.

Thyroid changes of pregnancy

Endocrine alterations characterized by thyroid enlargement, high levels of $T_3$ and $T_4$, normal $\text{TSH}$, and subclinical hypothyroidism.

Inferior vena cava syndrome

A condition in the supine position where the enlarged uterus compresses the inferior vena cava, causing decreased cardiac output and symptoms such as dizziness, light-headedness, and syncope.

ECG changes in pregnancy

Cardiovascular electrophysiologic shifts including an increased heart rate ($+15\%$), a $15^\circ$ left axis deviation, inverted T-waves in lead III, Q waves in lead III and AVF, and unspecific ST changes.

Hemodynamic changes in pregnancy

Circulatory increases including stroke volume ($+30\%$), heart rate ($+15\%$ or $15\,\text{beats/min}$), cardiac output ($+40\%$ to $50\%$), and oxygen consumption ($+20\%$), accompanied by a $5\%$ decrease in systemic vascular resistance (SVR).

Blood pressure changes in pregnancy

Vascular pressure decreases during normal gestation, characterized by a $10\,\text{mmHg}$ drop in systolic BP, a $15\,\text{mmHg}$ drop in diastolic BP, and a $15\,\text{mmHg}$ drop in mean BP.

Dilutional anemia of pregnancy

A physiologic drop in hemoglobin to approximately $110\,\text{g/L}$ caused by plasma volume expanding ($+40\%$ to $50\%$) significantly more than red blood cell volume ($+20\%$).

Hematologic profile in pregnancy

Maternal blood alterations comprising a $40\%$ rise in total blood volume, leukocytosis of $15,000/\text{ml}$, unchanged platelet counts, and an increased erythrocyte sedimentation rate up to $100\,\text{m/h}$.

Coagulation profile in pregnancy

A hypercoagulable state featuring a $50\%$ increase in fibrinogen (Factor I, $4.5\,\text{g/L}$ vs $3\,\text{g/L}$), elevations in Factors VII, VIII, IX, X, and XII, shortened PT and aPTT, and decreased fibrinolytic activity.

Maternal iron requirement

A cumulative pregnancy requirement of $1000\,\text{mg}$ ($500\,\text{mg}$ for maternal red cell mass expansion, $300\,\text{mg}$ for fetal development, and $200\,\text{mg}$ for normal losses), met by supplementing $300\,\text{mg}$ of ferrous sulfate daily (doubled for anemic patients).

Pulmonary changes in pregnancy

Respiratory adaptations including a $30\text{--}40\%$ increase in tidal volume and minute ventilation, increased $P\text{O}_2$, decreased $P\text{CO}_2$, a $15\%$ decrease in total lung capacity, and mild respiratory alkalosis.

Hyperemesis gravidarum

A severe form of morning sickness characterized by maternal weight loss, ketonemia, and electrolyte imbalance.

Pica

A dietary craving for non-food or abnormal substances during pregnancy.

Epulis

A condition marked by hyperemia and softening of the gums during pregnancy.

Renal hemodynamics in pregnancy

Urinary functional adaptations including slight kidney enlargement, a $35\%$ increase in renal plasma flow (RPF), a $50\%$ increase in glomerular filtration rate (GFR), and glucosuria in $50\%$ of pregnant women.

Urinary tract anatomical changes in pregnancy

Structural urinary changes comprising dilation of the renal pelvis and ureters (especially right-sided), reduced bladder tone and capacity, increased residual volume, and a heightened risk of pyelonephritis.

Mastodynia

Breast tenderness ranging from tingling sensations to frank pain caused by hormonal stimulation of the mammary ducts and alveolar system.

Montgomery’s tubercles

Enlarged circumlacteal sebaceous glands on the areola that become prominent during pregnancy.

Cutaneous hyperpigmentation in pregnancy

Dermatologic changes mediated by estrogen and melanocyte-stimulating hormone, including the darkening of linea alba into linea nigra, chloasma (face mask), and skin nevi.

Uterine adaptations in pregnancy

Maternal uterine growth from $50\,\text{g}$ to $1100\,\text{g}$ in weight, $< 10\,\text{ml}$ to $5\,\text{L}$ in capacity, and an increase in received cardiac output from $< 2\%$ to $15\text{--}20\%$.

Braxton Hicks contractions

Sporadic, irregular, asymmetrical, low-pressure, and painless uterine contractions that last less than $30\,\text{seconds}$.

True labor

Labor characterized by regular contractions that become stronger, longer, and closer together, cervical effacement and dilation, often a bloody show, a fixed fetal head, and contractions that do not stop with sedation.

False labor

Labor characterized by irregular contractions that show no change in characteristics, no cervical change, no bloody show, a ballotable fetal head, and contractions that cease following sedation.

Chadwick’s sign

A bluish or purplish discoloration of the cervix and vulva resulting from congestion of the pelvic vasculature.

Leukorrhea

An increased vaginal discharge during pregnancy that is rich in glucose and lactic acid, maintaining a low vaginal pH.

Metabolic weight gain distribution

A normal gestational weight gain of $12.5\,\text{kg}$, consisting of the fetus ($3400\,\text{g}$), fat/protein deposition ($3345\,\text{g}$), extravascular water ($1480\,\text{g}$), plasma/red cells ($1450\,\text{g}$), uterus ($960\,\text{g}$), amniotic fluid ($800\,\text{g}$), placenta ($650\,\text{g}$), and mammary glands ($405\,\text{g}$).

Musculoskeletal adaptations in pregnancy

Skeletal changes mediated by estrogen and relaxin, causing increased joint laxity in the pubic symphysis and sacroiliac joints, flattened foot arches (increasing shoe size by a half size or more), and lumbar lordosis.