Brodsky and Martin- MFM Flashcards
What happens to maternal HR in pregnancy?
Increased 10-15 bpm
What happens to maternal blood volume in pregnancy?
Increases 30-50% due to an increase in both plasma volume and RBCs
When does blood volume increase the most in pregnancy?
Second trimester (begins to increase during 1st, increases rapidly during 2nd, rises more slowly during 3rd)
Why does blood volume increase in pregnancy?
Leads to increased preload and : 1. Protects from impaired venous return when supine and erect, 2. Meets the demand of an extremely vascular uterus, 3. Protects the pregnant woman against large blood loss during delivery
What happens to blood pressure in pregnancy?
Decreases, lowest in 2nd trimester, also has a widened pulse pressure (because diastolic BP decreases more than systolic), decrease is due to decreased SVR
What happens to cardiac output during pregnancy?
Increases 30-50% with majority output to uterus and kidneys
In late pregnancy, in what position is cardiac output the greatest?
Lateral recumbent position (because supine impedes venous return- supine hypotensive syndrome)
How does pulmonary system change in pregnancy?
- Significant increase in TV with associated increase in minute ventilation
- Decreased residual volume
What acid/base status do pregnant women have and why?
Respiratory alkalosis with metabolic compensation (because increased progesterone induces a chronic hyperventilated state with a decrease in paCO2)
What happens to renal system in pregnancy?
- Renal hypertrophy, dilated calyces and ureters
- Increased GFR and blood flow (decreased BUN and creatinine)
- Decreased renal bicarbonate threshold, increased protein filtration
- Increased ADH, renin, angiotensisn II, and aldosterone secretion–> increased fluid volume and sodium retention
Do RBCs or plasma increase more in pregnancy?
Plasma, which leads to a dilutional anemia (but both plasma and RBCs are increasing, plasma is just increasing more)
What happens to WBCs in pregnancy?
Estrogen-mediated leukocytosis (greatest during labor), but despite high numbers there is decreased leukocyte function
What happens to platelets in pregnancy?
Minimal change in count but increased width and volume
What happens to coagulation in pregnancy?
Increased pro-coagulation factors and decrease anti-coagulation factors so a PRO-coagulation state, fibrinogen increases 30-50% because of estrogen effect
What puts a pregnant woman at risk for reflux?
Decreased gastric empting time, altered stomach position, and decreased lower esophageal sphincter tone
What puts a pregnant woman at risk for gallstones?
Impaired gallbladder contraction
What happens to pituitary in pregnancy?
Enlargement by 135% with increased prolactin production
What happens to thyroid hormones in pregnancy?
Increased thyroxine-binding globulin, increased total T4 with compensatory decrease in TSH. Woman remains euthyroid
What happens to PTH in pregnancy?
Significant increase in PTH-related hormone, which increases calcitriol production and leads to increased maternal intestinal absorption of calcium. Thus placental transfer of maternal calcium can occur while maternal serum calcium levels remain normal
Why do pregnant women have increased lipogenesis/fat storage?
Because estrogen stimulates pancreatic cells with associated increase in insulin
What produces hCG and what does it do?
Syncytiotrophoblasts. Prevent corpus luteum involution, suppresses maternal immune function, TSH-like effect
When is hCG most detected?
1st trimester
What is hPL, when is it most detected, and what does it do?
Human placental lactogen, increases with increased gestational age, increases lipid utilication, has anti-insulin effect
What does progesterone do during pregnancy?
Maintains uterus in a related state (smooth muscle relaxation); also has anti-inflammatory and immunosuppressive functions so it protects the fetus from immunological rejection by the pregnant woman
What happens to progesterone during labor
Requires a withdrawal of progesterone but concentrations stay the same so a functional suppression occurs dues to decreases in progesterone receptor and progesterone receptor co-activators as labor begins
Effect of estrogen during pregnancy
Regulates progesterone, assists with maturation of fetal organs and proliferation of uterine endometrium, contributes to labor by increasing strength of uterine contractions
What is the maternal portion of the placenta? How does it work?
Decidua basalis, divided into 10-38 lobes or cotyledons; oxygenated maternal blood from the endometrial arteries enters the intervillous space of the placenta in funnel-shaped spurts
What is the fetal portion of the placenta and how does it work?
Villous and chorion; contains numerous villi that are suspecded in the intervillous space
Type of transplacental transfer for: O2, CO2
Simple diffusion
Type of transplacental tranfer for: H2O
Simple diffusion
Type of transplacental transfer for: Na, Cl
Simple diffusion
Type of transplacental transfer for: Lipids
Simple diffusion
Type of transplacental transfer for: Fat-soluble vitamins
Simple diffusion
Type of transplacental transfer for: most medications
Simple diffusion
Type of transplacental transfer for: Glucose
Facilitated diffusion
Type of transplacental transfer for: Cephalexin
Facilitated diffusion
How does facilitated diffusion work?
Transfer is mediated by a carrier that moves compounds along the concentration gradient, no energy required for passage of compounds
Type of transplacental transfer for: Amino acids
Active transport
Type of transplacental transfer for: Calcium, phosphate, magnesium, iron, and iodide
Active transport
Type of transplacental transfer for: H2O-soluble vitamins
Active tranport
Type of transplacental transfer for: H2O, dissolved electrolytes
Bulk flow (transfer by hydrostatic or osmotic gradient)
Type of transplacental transfer for: Immunoglobulin G antibodies
Pinocytosis (compounds are engulfed, packaged and transferred across cell to opposite side)
When do maternal IgGs get transferred?
Begins early in 2nd trimester with MOST antibodies being transferred during the 3rd trimester
Type of transplacental transfer for: maternal or fetal cells
Breaks in the placental membrane
Can the following cross the placenta: Bilirubin
Yes
Can the following cross the placenta: aspirin
Yes
Can the following cross the placenta: Coumadin
Yes
Can the following cross the placenta: Dilantin
Yes
Can the following cross the placenta: Valproate
Yes
Can the following cross the placenta: Alcohol
Yes
Can the following cross the placenta: Maternal IgG
Yes
Can the following cross the placenta: TRH and iodine
Yes
Can the following cross the placenta: T4 and T3
Yes (small amount)
Can the following cross the placenta: Biliverdin
No
Can the following cross the placenta: Heparin
No
Can the following cross the placenta: Glucagon
No
Can the following cross the placenta: human growth hormone
No
Can the following cross the placenta: Insulin
No
Can the following cross the placenta: propylthiouracil
No (only small amounts cross)
Can the following cross the placenta: TSH
No
Can the following cross the placenta: Maternal IgM
No
Degrees of Placental Previa
- Complete- placental covers internal os completely
- Partial- placenta partially covers os
- Marginal- placenta just reaches os but does not cover it
- Low-lying- placenta implanted in lower uterine segment near os
Prevalence of placenta previa?
1 in 200 deliveries
Risk factors for placenta previa?
AMA, increased parity, previous c-section, maternal smoking, history of abortion
Clinical features of placenta previa?
Increased risk of preterm delivery, greater risk of fetal anomalies (increased by 2.5x, unclear reason), acute onset of painless vaginal bleeding (typically after late 2nd trimester), initial bleeding usually ceases spontaneously and often recurrs
Management of placenta previa with: severe bleeding
Deliver
Management of placenta previa with: preterm and no active bleeding
Close inpatient monitoring, antepartum steroids
Management of placenta previa with: mature
Deliver by c-section
Risk factors for placental abruption
Maternal hypertension, history of prior abruption, AMA, increased parity, cigarette smoking, cocaine use, increased thrombotic maternal state, external trauma, uterine leiomyoma
When do the majority of placental abruptions occur
Prior to labor
Maternal hemorrhage may lead to:
Maternal shock, severe anemia, consumptive coagulopathy, and/or renal failure
Risk factors for abnormal placental adherence
Co-existing placenta previa, history of curettage, increased parity, gravida 6 or more, implantation in lower uterine segment, or prior uterine surgery
What is a hydatidiform mole?
Molar pregnancy, abnormal chorionic villi with trophblastic proliferation and villous edema that is typically contained within uterine cavity
Types of hydatidiform mole
- Complete (majority 46 XX with mostly paternal origin, no feturs or amnion present, uterus large for GA, ~20% develop trophoblastic tumors)
- Partial (majority with 69 XXX, XXY, or XYY; nonviable fetus and amnion often present, uterus usually small for GA, less likely to develop trophoblastic tumors, rare to have medical complications)
Management of hydatidiform mole:
Immediately suction and evacuate mole, possible hysterectomy, assess for metastatic disease, follow closely for persistent trophoblastic proliferation or malignant changes by following beta-hCG levels
What is a chorioangioma?
A benign placental tumor
Can placental metastases occur?
Yes but rare. Have been seen with malignant melanoma, leukemia, lymphoma, breast cancer, lung carcinoma or sarcoma
Types of gestational trophoblastic disease
- Invasive mole (excessive growth with severe invasion, typically does not metastasize)
- Choriocarcinoma (very malignant trophoblastic tumor, rapidly growing invading uterine muscle and blood vessels, can lead to hemorrhage and/or necrosis, metastasis to lungs and vagina is common)
