MFM Flashcards
CV ∆ in pregnancy
- HR ↑ 10-15 BPM
- Blood volume ↑30-50% (most during 2nd trimester) causing ↑preload
- BP ↓ during 1st trimester and lowest in 2nd associated with widened PP and ↓ SVR
- CO ↑ 30-50% with↑ blood flow to kidneys and uterus
Pulmonary ∆ in pregnancy
- Minimal Change in RR
- ↑in TV w/ ↑ in MV associated with ↑ GA (TV * RR = MV)
- ↓ RV
- Progesterone induces a chronic hyperventilated state (↓ paCO2)
- ↑ O2 uptake and sensitivity to hypoxemia
Renal ∆ in Pregnancy
- Renal Hypertrophy
- ↑ GFR and RBF by 50%; ↓BUN and Cr
- ↓ Renal bicarb threshold; ↑ protein filtration
- ↑ ADH, renin Ang II and aldosterone secretion; ↑fluid volume and Na retention
Heme ∆ in Pregnancy
- RBCs ↑ by 30% (↑ need for Iron leading to ↑production, ↑MCV, ↑ Plasma volume - dilutional anemia)
- ↑ WBCs assoc w/ ↑ estrogen (greatest in labor) but ↓ function
- ↑ width and volume of platelets but minimal ∆ in count
- ↓ Hgb/Hct (due to ↑ Blood Volume despite erythropoiesis)
- ↑ Coagulation factors (↑ Fibrinogen 30-50%) and ↓ anti-coagulation factors (↓ Fibrinolysis)
GI ∆ in Pregnancy
- Uterus displaces stomach and intestines
- ↓ Gastric emptying time, ↓LES tone leading to reflux
- Hemorrhoids d/t constipation and ↑ Venous Pressure
- Impaired Gall Bladder contraction
Endocrine ∆ in Pregnancy
- Pituitary gland ↑ 135% assoc w/ PRL
- ↑TBG; ↑ Total T4 with ↓ TSH
- ↑ PTHr peptide leading to ↑ Calcitriol leading to maternal intestinal absorption of Ca (protects mom while transferring Ca to fetus)
- ↑ Insulin (Estrogen stimulates pancreas) leading to ↑ tissue glucose utilization and ↑ lipogenesis/fat storage
hCG in pregnancy
- Produced by syncytiotrophoblasts
- Highest in 1st trimester - detectable by 8-9 days following ovulation
- Prevents corpus luteum involution, TSH like effect, Suppresses maternal immune fxn
hPL in Pregnancy
- Produced by syncytiotrophoblasts
- ↑ w/ GA
- ↑ lipid utilization; has an anti-Insulin effect
Progesterone in Pregnancy
- Smooth muscle relaxation on uterus
- Withdrawal of fxn during labor - functional suppression
- Anti inflammatory and immonosuppressive fxns
Estrogen in Pregnancy
- Regulates progesterone, assists with maturation of fetal organs and proliferation of uterine endometrium
- Increases strength of Uterine Contractions
Maternal Portion of Placenta = Decidua Basalis
- Uterine Surface has 10-38 lobes or cotyledons
- O2 maternal blood enters from endometrial arteries into intervillous space
Fetal Portion of Placenta = Villous and Chorion and fetal blood flow
- UTERINE A. sends O2 blood into intervillous space where it mixes with deO2 blood and travels on gradient to capillaries within villi to form UMBILICAL V. that provides O2 and nutrients to fetus
- 2 UMBILICAL A. return blood to intervillous space and UTERINE V. then collects waste for maternal excretion
Transplacental Transfer
- Simple Diffusion (O2, CO2, H2O, Na, Cl, Lipids, Fat sol vits, Most meds)
- Facilitated Diffusion (Glucose, Cephalexin)
- Active Transport - Against Gradient (Amino Acids, Ca, Phos, Mg, Fe, Iodide and water soluble vits)
- Bulk Flow (H20, dissolved electrolytes)
- Pinocytosis (IgG Ab - starts in 2nd trim with most in 3rd, other proteins)
- Breaks (maternal or fetal cells)
Compounds that cross Placenta
Bilirubin
Aspirin, Coumadin
Dilantin, Valproate
Alcohol
Small Amount of T4 & T3 (also converted to T2 by placenta)
TRH and Iodine
IgG
Compounds that do NOT cross Placenta
Biliverdin
Heparin
Glucagon, HGH, Insulin
PTU (only small amounts cross)
TSH
IgM
Placenta Previa = C/s delivery
- Complete, Partial, Marginal, low-lying and varies with cervical dilation
- 1 in 200 deliveries; ↓ with ↑ GA, ↑ risk with AMA, ↑ parity, previous c/s, smoking, hx of abortion
- ↑ risk preterm delivery, ↑ risk fetal anomalies, ↑ bleeding
Placental Abruption
- total or partial separation of placenta leading to bleeding into decidua basalis
- Assoc w/ HTN, prior abruption, AMA, ↑ parity, Cigarettes, Cocaine, trauma, leiomyoma, ↑ thrombotic state
- Vaginal bleeding, uterine tenderness, fetal distress
- ↑ risk preterm delivery, ↑ risk stillbirth, ↑ risk growth restriction if chronic, ↑ risk neurological deficits
Abnormal Placental Adherence = planned early delivery
- Accreta (to myometrium), Increta (in myometrium), Percreta (past myometrium)
- May have ↑ AFP in early pregnancy
- may lead to severe hemorrhage, uterine perforation or infection
Placental Tumors
- Hydatidiform Mole
- Gest Trophoblastic Dz
- Chorioangioma - benign placental tumor
- Placental Mets - assoc with malignant melanoma, leukemia, lymphoma, breast CA, Lung CA or Sarcoma
Hydatidiform Mole = D&C and follow for malignancy
- 1 in 1000 (↑ risk AMA and previous hx of mole)
- Types: Complete (46, XX - paternal origin, no fetus or amnion, uterus large for GA and ~20% develop trophoblastic tumors, frequent medical comp.) Partial (69 XXX, XXY, XYY, nonviable fetus and amnion present, less likely to develop trophoblastic tumors, rare to have medical comp)
- Presents with bleeding, no fetus, rapidly developing uterus, preE in 2nd tri, ↑ BHCG for GA, ↑ trophoblastic tissue embolization
Gestational Trophoblastic Dz
- Invasive mole (excessive trophoblastic growth with severe invasion, usually no mets) and Choriocarcinoma (Malignant trophoblastic tumor that rapidly grows and invades uterine muscle and blood vessels with frequent mets to lungs and vagina)
- Irregular bleeding and persistently elevated BHCG
Single Umbilical A.
- 0.4-0.6% all infants
- 3-4 x more common with twins
- urogenital tract, GI and Cardiac anomalies associated
Velamentous Insertion of Cord
- 0.5-1% singletons, 9% twins, almost all triplets
- ↑ risk of labor intolerance
- ↑ risk prematurity and LBW
Vasa Previa = covering cervical Os
- 1 in 2,000-5,000 pregnancies
- ↑ risk low lying placenta or multiple gestation
- Frequently occurs with Velamentous insertion
- If unknown high mortality (40-90%)