Maternal, Fetal, and Placental Physiology and Pathology Flashcards
- Compared to the nongravid state, which compound is LEAST likely to change during pregnancy?
A. Pre-Beta-lipoprotein
B. Cholesterol
C. Free fatty acid
D. Insulin
E. Glucagon
E. To ensure a persistent source of metabolic fuel to the fetus, there are several vital changes in maternal hormones and feto-placental unit. Pre-β-lipoprotein, a very-low-density lipoprotein that normally represents a very small percentage of total lipoprotein, is increased in pregnancy. High-density lipoprotein (HDL) cholesterol levels increase in early pregnancy, whereas low-density lipoprotein (LDL) cholesterol levels increase later in pregnancy. The metabolic changes of pregnancy include hyperinsulinemia, insulin resistance, relative fasting hypoglycemia, increased circulating plasma lipids, and hypoaminoacidemia. During pregnancy, glucagon does not play a significant role as a diabetogenic factor and does not change appreciably.
- Human placenta is an incomplete steroidogenic organ, and estrogen synteshis by the placenta requires which of the following?
A. Dehydroepiandrosterone sulfate (DHEAS)
B. Cholesterol
C. 17-alpha-hydroxypregnenolone
D. Trophoblast cytochrome P450 (CYP) enzyme
E. Tumor necrosis factor-alpha (TNF-alpha)
A. In human parturition, maturation and activation of the fetal hypothalamic-pituitary-adrenal (HPA) axis is an important component. The activation of the axis is linked with increased production of dehydroepiandrosterone sulfate (DHEAS) from the intermediate zone of the fetal adrenal. DHEAS is directly aromatized in the placenta to estrone, and it can also be 16-hydroxylated in the fetal liver and converted in the placenta to estriol (16-hydroxy-17β-estradiol). This occurs because the human placenta is an incomplete steroidogenic organ, and estrogen synthesis by the placenta requires DHEAS as a steroid precursor. Cholesterol is the precursor to pregnenolone which is converted to progesterone in the placenta by 3-β hydroxysteroid dehydrogenase. Pregnenolone cannot be converted to 17 α-hydroxypregnenolone because the placenta lacks 17 α-hydroxylase. Among sheep and cows, parturition involves activation of the fetal HPA axis at term. In such animals, a sharp rise in the concentration of adrenocorticotropic hormone (ACTH) and cortisol in the fetal circulation occurs 15 to 20 days before delivery. This results in increased expression in the placenta of the Trophoblast cytochrome P450 (CYP) enzyme 17α-hydroxylase/C17,20-lyase (CYP17), which catalyzes the conversion of pregnenolone to 17α-hydroxypregnenolone and dehydroepiandrostenedione. The resultant fall in progesterone and rise in estrone and 17β-estradiol levels in the maternal circulation stimulate the uterus to produce PGF2α, which provides the impetus for labor in such animals. Creasy and Resnik’s Maternal-Fetal Medicine: Principles and Practice, 7th Edition: 68-9.
A 34 year old G1P0 female at 37 weeks gestation with decreased fetal movement andis diagnosed with fetal death. Which of the following is the most appropriate test in the evaluation?
A. Antinuclear antibody testing
B. Syphilis serology
C. Factor V Leiden mutation testing
D. Bile acids
E. Placental pathology
E. Stillbirth is defined as pregnancy loss that occurs after 20 weeks of gestation. In some cases, a cause is never identified, but using a comprehensive and thoughtful evaluation system proposed by the Stillbirth Collaborative Research Network yields a “possible or probable” cause of death in 76.2% of cases. The first part of the evaluation is a clear, thorough medical and obstetric history. This will guide the remainder of the evaluation; some testing is not routinely recommended, but a clue in the history may point a provider toward that test in a given patient. In all cases of stillbirth, the recommended tests are:
● -Fetal postmortem evaluation
● -Placental pathology
● -Karyotype or microarray if congenital anomaly/karyotype failure
● -Fetal-maternal hemorrhage testing (before induction of labor)
● -Antiphospholipid antibody testing
Any additional tests should be done only if there are indications from the history. This is true in particular of infectious workup, which should not otherwise be performed routinely (TORCH titer testing). Inherited thrombophilia workup is also not routinely indicated in cases of stillbirth.
ACOG Practice Bulletin 102: Management of Stillbirth.
. Which of the following conditions is most likely to result in a placenta that is small for gestational age?
A. Hydrops fetalis
B. Type II diabetes mellitus without end organ damage
C. Placenta previa
D. Maternal renal artery stenosis
E. Syphilis
D. Placental pathologic examination is an important component of the evaluation of stillbirth and many other obstetric and maternal/fetal disorders. In the hands of a trained pathologist, the gross and histologic examination of this unique organ can yield many diagnostic clues. A small for gestational age placenta, defined as <5% of expected weight for gestational age, can be seen as a result of many conditions that have a common origin of reduced uteroplacental blood flow leading to impairment of villous growth and development. Maternal conditions that cause these findings include hypertension and hypertensive disorders of pregnancy (preeclampsia, eclampsia) as well as diabetes mellitus with accompanying renal disease. Other conditions that result in impaired placental growth are aneuploidy and chronic infection. There are some conditions that cause large for gestational age placenta, defined as (>95% of expected weight for gestational age. Maternal diabetes (without renal disease as noted above), hydrops (both immune and nonimmune), and certain infections such as syphilis are known to cause enlargement of the placenta. Although placenta previa is listed as a possible answer, abnormal placentation is not associated with an increase or decrease in expected size.
Creasy & Resnick’s Maternal-Fetal Medicine: Principles and Practice, 7th edition, Chapter 45, p. 726.
- Which of the following is MOST likely to be deficient in a pregnant woman who adheres to a vegan diet?
A. Calcium
B. Vitamin D
C. Riboflavin
D. Vitamin B12
D. Precise data about the effect of vegetarian or vegan diets on perinatal outcomes are sparse. In women who are ovo-lacto vegetarians – that is, those who include eggs and/or dairy in their diet – there may be no deficiency. However, vegan women are most likely to have B12 deficiency because the primary source of this nutrient is animal food sources. These women should have their B12 levels assessed, and if low, encouraged to have B12 supplementation. This can be accomplished by incorporating foods such as meat substitutes or soy milk that are fortified with B12 by the manufacturer, or by taking injectable or oral supplementation. The other nutrients listed as answer choices (calcium, vitamin D, and riboflavin) as well as iron are also at risk of being below normal in vegan women, and should be monitored. These nutrients are readily available in the right plant based foods, and these women should be counseled to include those sources and/or other supplementation to ensure adequate levels.
- A 25 year old multigravida woman presents for her obstetrical visit at 27 weeks of gestation. She complains of headache and insomnia for the past 4 months, as well as episodes of diarrhea with up to 4 loose stools per day. On physical examination,you note bilateral proptosis, and her outstretched hands have a fine tremor. During the evaluation of her neck, there are no palpable masses, and the thyroid gland does not appear to be enlarged. Laboratory evaluation demonstrated a serum TSH of .8 mIU/L (elevated) in association with a serum total thyroxine of 15.1 mg/dL (elevated). Which of the following is the MOST likely diagnosis?
A. Graves disease
B. Toxic thyroid adenoma
C. TSH-producing pituitary tumor
D. Toxic multinodular goiter
E. Chronic thyroiditis
C. The patient exhibits the clinical signs of hyperthyroidism. The laboratory results suggest a thyroid-stimulating hormone (TSH)-producing pituitary adenoma consistent with excess TSH secreted from the pituitary (normal TSH in the second trimester is 0.2-3.0 mIU/L) and excess thyroxine secreted from the thyroid (normal total thyroxine in the second trimester is 7.5-10.3 mg/dL), with no feedback inhibition. TSH-secreting pituitary adenomas are rare, benign tumors that account for approximately 1% of all pituitary adenomas. These tumors produce excess TSH, which causes the thyroid gland to enlarge and produce thyroid hormone in excess, leading to clinical hyperthyroidism. Patients typically exhibit signs and symptoms of hyperthyroidism but may also present with headaches and visual field loss. Early diagnosis and correct treatment (generally surgical resection) optimize prognosis. In Graves disease, toxic thyroid adenoma, and toxic multinodular goiter, the TSH would be suppressed, and there would be an increased amount of thyroid hormone produced, leading to signs and symptoms of clinical hyperthyroidism. In patients with chronic thyroiditis, there is decreased thyroid hormone production from thyroid gland failure, and TSH is elevated.
- A 25 year old multigravida woman presents for her obstetrical visit at 27 weeks of gestation. She complains of headache and insomnia for the past 4 months, as well as episodes of diarrhea with up to 4 loose stools per day. On physical examination,you note bilateral proptosis, and her outstretched hands have a fine tremor. During the evaluation of her neck, there are no palpable masses, and the thyroid gland does not appear to be enlarged. Laboratory evaluation demonstrated a serum TSH of .8 mIU/L (elevated) in association with a serum total thyroxine of 15.1 mg/dL (elevated). Which of the following is the MOST likely diagnosis?
A. Graves disease
B. Toxic thyroid adenoma
C. TSH-producing pituitary tumor
D. Toxic multinodular goiter
E. Chronic thyroiditis
C. The patient exhibits the clinical signs of hyperthyroidism. The laboratory results suggest a thyroid-stimulating hormone (TSH)-producing pituitary adenoma consistent with excess TSH secreted from the pituitary (normal TSH in the second trimester is 0.2-3.0 mIU/L) and excess thyroxine secreted from the thyroid (normal total thyroxine in the second trimester is 7.5-10.3 mg/dL), with no feedback inhibition. TSH-secreting pituitary adenomas are rare, benign tumors that account for approximately 1% of all pituitary adenomas. These tumors produce excess TSH, which causes the thyroid gland to enlarge and produce thyroid hormone in excess, leading to clinical hyperthyroidism. Patients typically exhibit signs and symptoms of hyperthyroidism but may also present with headaches and visual field loss. Early diagnosis and correct treatment (generally surgical resection) optimize prognosis. In Graves disease, toxic thyroid adenoma, and toxic multinodular goiter, the TSH would be suppressed, and there would be an increased amount of thyroid hormone produced, leading to signs and symptoms of clinical hyperthyroidism. In patients with chronic thyroiditis, there is decreased thyroid hormone production from thyroid gland failure, and TSH is elevated.
- Which type of cancer is most likely to metastasize to the placenta?
A. Leukemia
B. Lymphoma
C. Melanoma
D. Breast cancer
E. Lung cancer
C. Malignant melanoma accounts for approximately 8% of malignant tumors during pregnancy. It is among the most aggressive forms of cancer and represents 31% of metastases to the placenta. If melanoma metastasizes to the placenta there is a 17% chance of it also metastasizing to the fetus. Hematologic malignancies are the second most common tumor to spread to the placenta and fetal dissemination has also been reported. Lung cancer is the leading cause of cancer death among women and is the second most common type of cancer in adult women behind breast cancer. Gabbe’s Obstetrics, 6th edition; pages 1078, 1090-1091.
- A patient presents for assessment of fetal growth at 32 weeks gestational age, and the fetus is noted to have ventriculomegaly and periventricular calcifications. She cares for 2 outdoor cats. Which of the following is the best test for the diagnosis for fetal infection?
A. Detection of toxoplasma DNA in amniotic fluid using PCR
B. Presence of toxoplasma IgM specific antibody
C. Detection of very high toxoplasma IgG antibody titer
D. Documentation of IgG seroconversion from negative to positive
E. Detection of toxoplasma DNA in maternal serum by PCR
A. Toxoplasma gondii is a protozoan that is dependent on wild and domestic cats, which are the only known host for the oocyte. It has three distinct life forms: trophozoite, cyst, and oocyst. The invasive trophozoite is released in the intestines of animals, such as cows, that ingest the oocyst. Human infection occurs when infected meat is ingested or oocysts are ingested via contamination by cat feces. Most infections in immunocompetent humans are asymptomatic, and approximately half of all adults in the US have an antibody to toxoplasma. Immunity is usually long-lasting. The frequency of seroconversion during pregnancy is approximately 5%, and clinically significant infection occurs in just 1 in 8000 pregnancies. About 3 in 1000 infants show evidence of congenital infection, but 40% of neonates born to mothers with acute toxoplasmosis have evidence of infection, particularly when maternal infection develops during the third trimester. Clinical manifestations can include a disseminated purpuric rash, hepatosplenomegaly, ascites, chorioretinitis, uveitis, periventricular calcifications, ventriculomegaly, seizures, and developmental delay. Maternal infection is best confirmed by PCR of the maternal serum. While serologic tests for toxoplasma IgM, high-titer IGG, and documentation of seroconversion are suggestive of an acute Infection, detection of toxoplasma DNA in amniotic fluid using PCR is the best test for confirmation of fetal infection. Creasy and Resnick’s Maternal-Fetal Medicine: Principles and Practice, 7th edition, Chapter 51, page 847.
Which of the following cardiac lesions has the poorest prognosis in pregnancy?
A. Moderate aortic stenosis
B. Hypertrophic cardiomyopathy
C. Unrepaired ventricular septal defect (VSD) with right to left shunt and pulmonary hypertension
D. Marfan syndrome with aortic root diameter 3 cm
E. Unrepaired aortic septal defect (ASD)
C. Unrepaired ventricular septal defect (VSD) with right-to-left shunt and pulmonary hypertension is the correct answer. Eisenmenger syndrome is a a congenital heart defect that is characterized by communication between the pulmonary and systemic circulations. The most common underlying defect in these patients is a large VSD. The communication between the higher pressure system of the left, and right ventricle leads initially to a left to right shunt of blood toward the pulmonary vasculature. The increase in the pulmonary vasculature over time leads to pulmonary hypertension and hypertrophy. Eventually, right-sided pressures increase to maintain perfusion and ultimately lead to a shunt reversal resulting in a right to left shunt. Pregnancy carries a 50% risk of mortality in these patients, though newer data places the risk at closer to 25%. In women who survive there is an increased risk of poor outcomes for the fetus as well. Sudden death can occur at any time; however, labor, delivery, and immediately postpartum carry the highest risk. Management during pregnancy focuses on maintaining pulmonary blood flow and avoiding hypotension. Times of greatest risk during labor include administration of regional anesthesia and postpartum hemorrhage. Women with Eisenmenger syndrome tend to tolerate normal blood loss; however, postpartum hemorrhage and the resulting hypotension are poorly tolerated. These patients need a planned delivery with intensive monitoring and multidisciplinary care. Aortic stenosis in reproductive-aged women is most often due to a bicuspid aortic valve. Stenosis worsens over time due to calcification and restriction in leaflet motion. Women with mild to moderate aortic stenosis tolerate pregnancy well. Severe (or “critical”) aortic stenosis is not well tolerated during pregnancy and can be life-threatening. The underlying mechanism of adverse outcomes is related to a fixed cardiac output. Throughout pregnancy, there are multiple factors that lead to decreased preload therefore further worsening a fixed cardiac output. This includes regional anesthesia and hemorrhage. The maternal mortality rate associated with severe aortic stenosis is 8% with the greatest risk to women whose valve gradient exceeds 100 mm Hg. Hypertrophic cardiomyopathy is an autosomal dominant condition that causes cardiac hypertrophy, myocyte disarray, and interstitial fibrosis. In addition to ventricular hypertrophy, there may or may not be left ventricular outflow tract obstruction. Common symptoms are dyspnea, chest pain, syncope, and arrhythmias. In patients with outflow tract obstruction, there is worsening during pregnancy due to the normal decrease in peripheral vascular resistance. Valsalva during labor can result in an increase in outflow tract obstruction and should be minimized. Sudden death can occur due to complex arrhythmias. Marfan syndrome is an autosomal dominant condition with variable expressivity. The condition is characterized by a defect in connective tissue particularly fibrillin. This weakness can especially be seen in the aorta increasing the risk of complications such as aortic dissection. Women whose aortic root is >40mm are at the greatest risk of death during pregnancy. Risk of aortic dissection with an aortic root <40mm is 1% and approximately 10% if the diameter is greater than 40mm. If the aortic root diameter is >50mm elective aortic root repair should be done prior to pregnancy. During pregnancy goals of treatment are to decrease the pulsatile forces on the aorta with the use of a β-blocker. Aortic septal defect (ASD) is the most common congenital heart lesion and results in left to right shunt. Women usually do not have any symptoms and physical findings are often subtle. Pregnancy is well tolerated unless pulmonary hypertension develops. A small percentage of patients have arrhythmia most commonly atrial flutter or atrial fibrillation. If these develop they should be treated accordingly with antiarrhythmics. Williams Obstetrics 23rd Ed., Chapter 44 Cardiovascular Disease Creasy and Resnick 7th Ed, Chapter 52 Cardiac Disease
- A 27 year old G1P0 at 36 weeks dated by her last menstrual period consistent with an 8 week ultrasound presents for a growth ultrasound for size less than dates. Her ultrasound performed at 19 weeks showed normal anatomy. Today’s ultrasound shows the overall estimated fetal weight at 8th%ile, amniotic fluid volume of 16 cm, and normal umbilical artery dopplers. The patient wants to know how much weight the fetus should be gaining weekly at this point in her pregnancy. What do you tell her is the median weight gain per week?
A. 50 grams per week
B. 150 grams per week
C. 200 grams per week
D. 250 grams per week
E. 100 grams per week
C. Fetal growth restriction (FGR) affects less than 10% of infants born in developed countries and up to 30% of infants born in developing countries. Varying definitions of fetal growth restriction and the use of different growth curves contribute to the wide variation of FGR rates. A publication from 1982 reported outcomes of over 2.2 million live births in California from 1970 – 1976. Using the 50th percentile, growth curves were plotted for singletons and twin gestations. For singletons, the growth rate peaks at 250 grams at 33 weeks. For the patient in this question, at 36 weeks the median growth rate is approximately 200 grams per week. Of note, singleton and twin growth curves are nearly identical through 26 weeks.
- A 27 year old G1P0 at 36 weeks dated by her last menstrual period consistent with an 8 week ultrasound presents for a growth ultrasound for size less than dates. Her ultrasound performed at 19 weeks showed normal anatomy. Today’s ultrasound shows the overall estimated fetal weight at 8th%ile, amniotic fluid volume of 16 cm, and normal umbilical artery dopplers. The patient wants to know how much weight the fetus should be gaining weekly at this point in her pregnancy. What do you tell her is the median weight gain per week?
A. 50 grams per week
B. 150 grams per week
C. 200 grams per week
D. 250 grams per week
E. 100 grams per week
C. Fetal growth restriction (FGR) affects less than 10% of infants born in developed countries and up to 30% of infants born in developing countries. Varying definitions of fetal growth restriction and the use of different growth curves contribute to the wide variation of FGR rates. A publication from 1982 reported outcomes of over 2.2 million live births in California from 1970 – 1976. Using the 50th percentile, growth curves were plotted for singletons and twin gestations. For singletons, the growth rate peaks at 250 grams at 33 weeks. For the patient in this question, at 36 weeks the median growth rate is approximately 200 grams per week. Of note, singleton and twin growth curves are nearly identical through 26 weeks.
- Ms AT is an asian G1P0 female at 28 weeks gestation with a singleton fetus demonstrating findings of hydrops fetalis but no identifiable structural anomalies on detailed obstetric imaging and fetal echocardiography. No arrhythmia is identified, and the peak systolic velocity of the fetal middle cerebral artery measures 1.8 MoMs. Her blood type is O with Rh(D) positivity, and her antibody screen is negative. Kleihauer-Betke testing is negative. The maternal hemoglobin concentration is 10.5 gm/dL with an MCV of 73 fL. Amniocentesis reveals a normal karyotype with negative polymerase chain reaction studies for parvovirus, toxoplasmosis, and cytomegalovirus infection. What is the most likely cause of the hydrops fetalis?
A. Red cell alloimmunization
B. Fetal hemorrhage
C. Infection
D. Lysosomal storage disease
E. Fetal hemoglobinopathy
E. This case represents non-immune hydrops fetalis associated with fetal anemia (as denoted by the increased MCA peak systolic velocity > 1.5 MoMs). The work-up has been thorough and has identified a potential cause. Her negative antibody screen excludes maternal red cell alloimmunization as the inciting event. The negative Kleihauer-Betke screen excludes fetal hemorrhage. The amniocentesis results make fetal infection or aneuploidy unlikely causes. Metabolic disorders such as lysosomal storage diseases account for 1-2% of cases of NIHF and are rare. This woman’s Asian heritage, mild anemia, and low MCV (< 80 fL) indicate the potential for her to have alpha thalassemia minor. Alpha thalassemia is an autosomal recessive disorder common in the Southeast Asian population where it accounts for 28-55% of cases of NIHF. There are 4 functional alpha-globin genes responsible for the production of the alpha-globin chains of normal adult hemoglobin. Women with loss of two of the four alpha-globin genes are said to have alpha thalassemia minor, and Asian women tend to have the “cis” deletional form in which both alpha genes on one of the two chromosomes have been deleted (aa,–). If this woman’s partner also has alpha thalassemia minor, their offspring have a 25% chance of loss of all four alpha-globin genes (–,–) and having no functional alpha-globin production – Hemoglobin Barts, which presents with hydrops fetalis and is incompatible with extrauterine life. If the partner has alpha thalassemia minima with loss of only one of the four alleles, their offspring have a 25% of having Hemoglobin H disease with loss of 3 of the 4 alleles and hemolytic anemia and occasionally hydrops fetalis.
Society for Maternal-Fetal Medicine (SMFM), Norton ME, Chauhan SP, Dashe JS. Society for Maternal-Fetal Med
- A 27 year old F2P1001 at 32 weeks gestation comes in for a follow-up obstetric visit. Her health is complicated by diabetes and asthma. At her last visit, she had elected to further discuss antenatal Tdap vaccination next time. Today, she questions the benefits of receiving a Tdap vaccine. Which of the following is NOT a benefit of tdap vaccination?
A. The Tdap vaccine has been given during pregnancy without reportable safety concerns
B. The tdap vaccine is important to public health as a booster vaccine in order to minimize the circulating pool of available hosts given waning immunity
C. Newborns do relatively well should they become infected with bordetella pertussis
D. The tdap vaccine is ebenfical to her in reducing her change of getting pertussis in light of rising baseline incidence
E. Antenatal tdap vaccine leverages vertical transmission of maternal antibodies
C. Pertussis (whooping cough) is an acute and prolonged infectious cough illness caused by Bordetella pertussis. The prevalence of pertussis in the United States has been increasing due to waning immunity in adults. Adults who develop whooping cough can pass it on to susceptible infants who are unvaccinated. Whooping cough can cause serious and occasionally life-threatening infections in babies, especially in the first six months of life. Infants do not get their first pertussis vaccine until they are 2 months of age, leaving a time period of vulnerability between birth and vaccination. In 2013 the Advisory Committee on Immunization Practices (ACIP) of the CDC issued guidelines recommending that women receive the Tdap vaccine in the third trimester of pregnancy regardless of when their last vaccine was given in order to maximize maternal antibody response and passive antibody transfer to the fetus. The optimal timing of vaccination is between 27-36 weeks gestation. No adverse reactions have been attributed to the Tdap vaccine. The most common side effects are local reactions such as redness and pain at the injection site. . ACOG Committee Opinion 566: Update on Immunization in Pregnancy: Tetanus, Diphtheria, and Pertussis Vaccination.
. What happens to apocrine and eccrine gland activity in pregnancy?
A. Decrease in apocrine gland activity, increase in eccrine gland activity
B. Decrease in apocrine gland activity, decrease in eccrine gland activity
C. Increase in apocrine gland activity, increase in eccrine gland activity
D. Increase in apocrine gland activity, decrease in eccrine gland activity
A. There are two main types of sebaceous glands. The apocrine glands empty into the hair follicles and are found primarily in the axilla and groin. The eccrine glands are found throughout the body in varying densities. It is believed that apocrine activity decreases during pregnancy, leading to an improvement in Fox-Fordyce disease and hidradenitis suppurativa. Conversely, eccrine activity increases in pregnancy leading to exacerbation of miliaria, hyperhidrosis, and dyshidrosis.
- Which of the following is NOT an essential element of appropriate blood pressure measurement?
A. Use a sitting or semi-reclining position with back supported and arm at heart level
B. Obtain correct size cuff: width of bladder 40% of circumference and encircles 80% of arm
C. Patients feet should be flat, not dangling from examination table or bed and her legs uncrossed
D. Consumption of nicotine or caffeine within 30 minutes of measurement should delay instituting antihypertensive therapies for severe range blood pressures as the blood pressure is likely falsely elevated and will likely soon return to normal
E. Have the patient to sit quietly for five minutes prior to assessment
Answer:
D. One of the most important factors in the identification and management of hypertension in pregnancy is the standardized and appropriate measurement of blood pressure. The following details the essential aspects of measuring blood pressure in the obstetric patient.
Step 1: Prepare equipment.
1. Mercury sphygmomanometer is the gold standard; can use validated equivalent automated equipment
a. Check cuff for any defaults.
b. Obtain correct size cuff: width of bladder 40% of circumference and encircle 80% of arm.
Step 2: Prepare the patient.
1. Use a sitting or semi-reclining position with back supported and arm at heart level.
2. Have patient sit quietly for 5 minutes prior to measurement.
3. Bare upper arm of any restrictive clothing.
4. Patient’s feet should be flat, not dangling from examination table or bed, and her legs uncrossed.
5. Assess any recent (within the previous 30 minutes) consumption of caffeine or nicotine. If blood pressures are at the level that requires treatment, consumption of nicotine or caffeine should not lead to delays in instituting appropriate antihypertensive therapies.
Step 3: Take measurement.
1. Support patient’s arm at heart level, seated in semi-fowlers position.
2. For auscultatory measurement: use first audible sound (Kortokoff I) as systolic pressure and use disappearance of sound (Kortokoff V) as diastolic pressure.
3. Read to the nearest 2 mm Hg.
4. Instruct the patient not to talk.
5. At least one additional reading should be taken within 15 minutes.
6. Use the highest reading.
7. Do not reposition the patient to either side to obtain a lower BP. This will give you a false reading.
Step 4: Record measurement.
1. Document BP, patient position, and arm in which taken.
CMQCC Preeclampsia Toolkit. Accurate Blood Pressure Measurement. https://www.cmqcc.org/resource…Accessed May 27, 2021.
Peters RM. High blood pressure in pregnancy. Nurs Womens Health. 2008;12(5):410-422
. Which of the following correctly identifies changes in respiratory physiology in pregnancy?
A. Respiratory rate increases, tidal volume unchanged, total lung capacity decreases, PaO2 levels increase
B. Respiratory rate unchanged, tidal volume decreases, total lung capacity decreases, PaO2 levels increase
C. Respiratory rate unchanged, tidal volume increases, total lung capacity decreases, PaO2 levels increase
D. Respiratory rate decreases, tidal volume decreases, total lung capacity decreases, PaO2 levels decreases
E. Respiratory rate increases, tidal volume increases, total lung capacity increases, PaO2 levels increase
Definitions:
Respiratory Rate – number of breaths per minute
Vital capacity – maximal amount of air that can be forcibly expired after maximal inspiration (inspiratory capacity + Expiratory reserve volume)
Inspiratory capacity – Maximal amount of air that can be inspired from resting expiratory level (total volume + inspiratory reserve volume)
Tidal volume – Amount of air inspired and expired with a normal breath
Inspiratory reserve volume – maximal amount of care that can be inspired at the end of normal respiration
Functional residual capacity – amount of air in the lungs at resting expiratory level (expiratory reserve volume + residual volume)
Expiratory reserve volume – maximal amount of air that can be expired from resting expiratory level
Residual volume – Amount of air in the lungs after maximal expiration
Total lung capacity – total amount of air in lungs at maximal inspiration (vital capacity + residual volume)
C. During pregnancy, the diaphragm rises approximately 4 cm and the subcostal angle widens allowing the transverse diameter of the rib cage to increase by approximately 2 cm. This rise in the diaphragm leads to a decrease in the total lung capacity and functional residual capacity (includes expiratory reserve volume and residual volume which both decrease). Functional residual capacity decreases by approximately 20%. Tidal volume and minute ventilation increase significantly as pregnancy advances. The increases in tidal volume are approximately 30-50%, which is likely due to increased respiratory drive related to increases in progesterone. Although there is an increase in tidal volume, the respiratory rate remains unchanged during pregnancy. Pregnancy is a state of chronic mild hyperventilation which results in increased alveolar oxygen (PaO2) and decreased arterial carbon dioxide (PaCO2). The lower PaCO2 results in a chronic respiratory alkalosis. This is compensated through an increase in excretion of bicarbonate which maintains a relatively stable pH.
- Which of the following is the most common infectious cause of non-immune hydrops?
A. CMV
B. Parvovirus
C. Toxoplasmosis
D. Syphilis
E. Rubella
Answer:
B. Parvovirus B19 infection is caused by a DNA virus that is transmitted primarily by respiratory droplets and infected blood products. Immunity increases progressively with age such that 50-60% of reproductive-age women have evidence of prior infection and immunity. The most common clinical manifestation of infection is erythema infectiousum (5th disease), which usually includes a low-grade fever, malaise, myalgias, arthralgias, and a “slapped cheek” facial rash. After acute parvovirus B19 infection during pregnancy, rates of maternal to fetal transmission range from 17-33%. Most cases resolve spontaneously, but an estimated 8-10% (and potentially up to 18-27%) of cases of non-immune hydrops fetalis are associated with parvovirus B19 infection. The virus is cytotoxic to erythroid precursors, and hydrops most often results from aplastic anemia, although hydrops can also be related to myocarditis or chronic fetal hepatitis. Severe effects are seen most frequently among fetuses when maternal infection occurs before 20 weeks of gestation.
Duff, P. (2014) Maternal and Fetal Infections In R.K. Creasy, R. Resnik, J.D. Iams, C.J. Lockwood, T.R. Moore and M.F. Greene. (Eds.) Creasy & Resnik’s Maternal-Fetal Medicine (7th ed., pp 838-9). Philadelphia, PA: Elsevier-Saunders.
ACOG Practice Bulletin no. 151: Cytomegalovirus, parvovirus b19, varicella zoster, and toxoplasmosis in pregnancy. Obstet Gynecol. 2015 Jun; 125(6) 1510-25.
what does PCWP measure
Pulmonary capillary wedge pressure (PCWP) is a measurement used to assess the left side of the heart and estimate the pressure within the left atrium. It indirectly reflects the pressure within the pulmonary veins and the left ventricle.
PCWP is typically measured using a pulmonary artery catheter (also known as a Swan-Ganz catheter) that is threaded through the right side of the heart and into the pulmonary artery. The balloon at the tip of the catheter is inflated and then wedged into a small branch of the pulmonary artery. This occludes the blood flow, allowing the measurement of pressure within the pulmonary capillaries.
PCWP is an important parameter in evaluating cardiac function and assessing the severity of heart failure. It is commonly used to estimate left ventricular end-diastolic pressure (LVEDP), which is a reflection of the filling pressure of the left ventricle during diastole. PCWP is also used to guide the management of certain cardiac conditions, such as determining optimal fluid status or assessing the effectiveness of interventions.
By measuring PCWP, healthcare professionals can gather information about the pressures within the left side of the heart and make informed decisions regarding treatment and management strategies for cardiac patients.
- Which of the following describe the changes that occur to cardiac physiology during pregnancy?
A. Increased cardiac output, decreased systemic vascular resistance, decreased maternal heart rate, increased pulmonary capillary wedge pressure
B. Decreased cardiac output, decreased systemic vascular resistance, increased maternal heart rate, increased pulmonary capillary wedge pressure
C. Increased cardiac output, increased systemic vascular resistance, unchanged maternal heart rate, unchanged pulmonary capillary wedge pressure
D. Increased cardiac output, decreased systemic vascular resistance, increased maternal heart rate, unchanged pulmonary capillary wedge pressure
E. Increased cardiac output, decreased systemic vascular resistance, decreased maternal heart rate, decreased pulmonary capillary wedge pressure
D. Cardiac output increases by approximately 30-50%, with approximately 50% of the increase occurring by 8 weeks of gestation. Increases in cardiac output are related to an increase in preload, which is due to the associated increase in blood volume; a decrease in afterload, which is due to a decrease in systemic vascular resistance; and an increase in maternal heart rate. Cardiac output appears to peak between 25-30 weeks of gestation. Systemic vascular resistance decreases in pregnancy, usually occurring early in gestation and nadirs by the mid-second trimester with increases occurring gradually in the third trimester. At term, the systemic vascular resistance remains 21% lower than pre-pregnancy values. Changes in vascular resistance are related to progesterone-mediated smooth muscle relaxation leading to vasodilation. The factors related to vasodilation are not completely understood but appear to be related to increased endothelial prostacyclin and increased nitric oxide production. Maternal heart rate increases by approximately 15-20 bpm during pregnancy and is the major contributor to increases in cardiac output towards the end of pregnancy. Plasma volume increases by approximately 10-15% in early pregnancy and continues to increase throughout pregnancy. Pulmonary vascular resistance decreases significantly during pregnancy; however, pulmonary capillary wedge pressure and central venous pressure do not change during pregnancy. Increases in pulmonary capillary wedge pressure increase the risk of pulmonary edema.
Williams Obstetrics 23rd ed., Chapter 5: Maternal Physiology
Gabbe’s Obstetrics: Normal and Problem Pregnancies 6th ed., Chapter 3: Maternal Physiology.
- Which of the following is the most abundant secretory hormone produced by the placenta?
A. Prolactin
B. Estriol
C. hCS (human chorionic somatomammotropin)
D. DHEAS
E. Progesterone
C. The correct choice is hCS, human chorionic somatomammotropin. This is a peptide hormone similar to human growth hormone (hGH) and prolactin in structure. When it was first isolated, it was named human placental lactogen (hPL). Since then, it has been found to have minimal effect on lactation and therefore that designation is a misnomer. There are three genes coding for hCS is on the long arm of chromosome 17, and these are expressed in syncytiotrophoblast cells. The transcription rate of the hCS genes is constant throughout gestation, and as placental mass increases the rate of production increases accordingly. At term, the placenta produces approximately 1-4 grams of hCS per day, and the levels in the maternal serum range from 5-15 μg/mL. Despite its large quantities, the function of hCS is not well defined. Given its homology to hGH, it is hypothesized that it has functions in fetal growth and nutrition, however normally grown healthy infants have been born to women with low or absent levels of hCS.
- Which of the following is the most abundant secretory hormone produced by the placenta?
A. Prolactin
B. Estriol
C. hCS (human chorionic somatomammotropin)
D. DHEAS
E. Progesterone
C. The correct choice is hCS, human chorionic somatomammotropin. This is a peptide hormone similar to human growth hormone (hGH) and prolactin in structure. When it was first isolated, it was named human placental lactogen (hPL). Since then, it has been found to have minimal effect on lactation and therefore that designation is a misnomer. There are three genes coding for hCS is on the long arm of chromosome 17, and these are expressed in syncytiotrophoblast cells. The transcription rate of the hCS genes is constant throughout gestation, and as placental mass increases the rate of production increases accordingly. At term, the placenta produces approximately 1-4 grams of hCS per day, and the levels in the maternal serum range from 5-15 μg/mL. Despite its large quantities, the function of hCS is not well defined. Given its homology to hGH, it is hypothesized that it has functions in fetal growth and nutrition, however normally grown healthy infants have been born to women with low or absent levels of hCS.
. A 22 year old G1P0 at 35 weeks gestation with a history of childhood asthma is seen in the clinic. Which blood gas would be most consistent with a healthy pregnancy at sea level? Answers given as arterial pH/Arterial PO2 (mmHg)/Arterial PCO2 (mmHg)/Sodium bicarbonate (mEq/L)
A. 7.4/102/28/20
B. 7.3/78/23/20
C. 7.5/100/23/16
D. 7.4/100/45/26
A. Due to an increase in tidal volume and decrease in functional residual capacity, there is a relative hyperventilation in pregnancy, which results in a compensated respiratory alkalosis. The pH remains around the non-pregnant level (7.4-7.48). The arterial PO2 is moderately increased due to greater alveolar ventilation (101-104 mm Hg). The PCO2 is decreased (26.9-32.5 mm Hg) due to a combination of the hyperventilation effects of progesterone and the increased production of CO2 related to the increased metabolic rate. To compensate for decreased CO2, there is an equivalent increase in the renal excretion of bicarbonate to maintain an unchanged pH (bicarbonate range in pregnancy 18-26 mEq/L).
- A 35 year old G3P2 female at 28 weeks of gestation with a history of moderate persistent asthma was recently hospitalized for an asthma exacerbation and is being sent home on a medium-dose inhaled corticosteroid and an albuterol rescue inhaler. She plans on using a peak expiratory flow rate meter (PEFR). How should she be counseled regarding response to the inhaler?
A. A good response is defined as PEFR 60% of expected
B. A good response is if her PEFR is 224 L/min
C. An incomplete response is defined as PEFR <50% and she should repeat her albuterol treatment at 20-minute interval s up to 2 more times
D. An incomplete response is defined as PEFR 80% or less of expected, and she should use albuterol treatment at 20 minute intervals up to 2 more times and reassess PEFR
E. A poor response is defined as PEFR 70% of expected adns she should repeat her albuterol treatment and obtain emergency care
D. The correct answer is: an incomplete response is defined as PEFR 80% or less of expected and she should use albuterol treatment at 20-minute intervals up to 2 more times and reassess her PEFR. PEFR is the forced expiratory volume in 1 minute. It can be used in pregnancy to help determine the severity of asthma in patients and the appropriate response to treatment. Although the PEFR varies with position (standing > sitting > supine) the value is stable throughout gestation (>320 standing, >310 sitting, >300 supine). A patient’s asthma can be monitored by % of the predicted best.
In women with intermittent and mild persistent asthma, their PEFR is >80%. When the PEFR decreases to 60-80% of the predicted best, this would be considered not controlled moderate persistent asthma. When asthma is very poorly controlled and the PEFR is <60%, this is considered severe persistent asthma.
Home management of acute asthma exacerbation has been outlined by the National Asthma Education and prevention program. An albuterol metered-dose inhaler (MDI) at a dose of 2-4 puffs is the initial line of treatment. A GOOD response is if PEFR is > 80% and there is no wheezing/shortness of breath and normal fetal movement. With a GOOD response, the MDI can be repeated every 3-4 hours as needed. An INCOMPLETE response is PEFR of 50-80% OR if wheezing/ shortness of breath persists. With an INCOMPLETE response, the MDI should be repeated at the same dose at 20-minute intervals up to 2 more times. If the repeat PEFR is still 50-80% of predicted or if decreased fetal movement, contact the caregiver or seek emergency care. A POOR response is if PEFR is <50% of predicted OR severe wheezing and shortness of breath or decreased fetal movement. The MDI should be repeated and emergency care should be obtained. Reference ranges for % of predicted PEFR are similar for hospitalized patients with a GOOD response being > 70%, INCOMPLETE response 50-70%, and POOR response < 50%.
- A 25 year old G1P0 female at 18 weeks gestation presents to you fro consultation regarding her history of SLE. She has a history of high titers of anti-Ro/SSA antibodies. SHe had an ultrasound today demonstrating a normal fetal heart rate with atrio-ventricular synchrony. How would you counsel her regarding potential for her fetus developing congenital heart block?
A. The risk of her fetus developing congenital complete heart block (CCHB) is small, but when it occurs CCHB associated with maternal anti-Ro/SSA antibodies is irreversible and carries a significant morbidity and mortality risk for the affected offspring.
B. Monitoring with weekly fetal echocardiograms to assess PR intervals is recommended, because a prolonged PR interval precedes more advanced heart block.
C. Anti-Ro/SSA antibodies do not cross the placenta at 18 weeks, so her fetus is not at risk for congenital heart block.
D. In this nullipara with SLE, hydroxychloroquine is recommended because it is proven to significantly reduce the risk of fetal heart block in any woman with anti-Ro/SSA antibodies.
A. Anti-Ro/SSA and anti-La/SSB antibodies cross the placenta and enter the fetal circulation to potentially induce fetal injury. Congenital complete heart block (CCHB) is one manifestation and most commonly occurs between 16 and 24 weeks of gestation. CCHB is irreversible due to fetal cardiac conduction system damage that occurs in utero. Other findings of neonatal lupus syndrome (NLS) include rash, hepatitis, hemolytic anemia, and thrombocytopenia, all of which are transient. NLS occurs in women with anti-Ro/SSA and/or anti-La/SSB, even if the mother is clinically well. In the absence of having previously delivered an infant with NLS, women with anti-Ro/SSA have a 2-3% risk of having a liveborn child with CCHB. However, among women with a previously affected child born with CCHB, the recurrence risk for heart block is 17% to 20%. The PRIDE study assessed the utility of monitoring with serial fetal echocardiograms performed from 16 to 26 weeks gestation to assess the PR interval. They found that prolongation of the PR interval was uncommon, and could not reliably be shown to precede CCHB. CCHB and cardiomyopathy were noted to occur within 1 week of a normal echocardiogram, suggesting that serial monitoring with fetal echocardiograms may not helpful for identifying which fetuses will develop CCHB, especially in women who have not previously had a fetus with CCHB.
No pharmacologic therapy has been found to reverse CCHB in an affected fetus; however, several therapies have been investigated in treating second-degree heart block, cardiomyopathy, and hydrops. Fluorinated steroids may be beneficial in treating second-degree heart block, although there is potential for major maternal and fetal side effects, so further study is warranted. In CCHB, beta-agonists have been used to increase the fetal ventricular rate, though they are associated with significant maternal side effects and their effect on reducing fetal/neonatal mortality remains unproven. Theoretically, plasmapheresis may aid in the prevention and treatment of fetal congenital heart block by lowering levels of anti-Ro/SSA and anti-La/SSB antibodies, but only case reports have been published. IVIG has shown promise in treating fetal cardiomyopathy but has not been shown to reduce the recurrence risk in women with a previously affected child. Retrospective studies suggest that hydroxychloroquine may decrease the recurrence risk of fetal congenital heart block in women with a previously affected child, and this drug has been used safely and regularly in pregnancy for other indications. A clinical trial is currently underway to further investigate the utility of hydroxychloroquine in this population of women.
- A 36 year old hispanic multiparous woman was diagnosed with peripartum cardiomyopathy three weeks following her most recent delivery. Which of the following is the most important factor for counseling regarding future pregnancies?
A. Ejection fraction at time of diagnosis
B. Severity of symptoms at time of presentation
C. Ejection fraction 12 months following diagnosis
D. Interval between delivery and presentation with symptoms
C. Peripartum cardiomyopathy or idiopathic cardiomyopathy in pregnancy is a diagnosis of exclusion following evaluation for other causes of heart failure. The incidence varies widely and is reported in the US as 1 in 3000 to 4000. Diagnostic criteria includes:
1. Development of heart failure during the last month of pregnancy or within 5 months postpartum
2. Absence of other identifiable causes of heart failure
3. Absence of recognizable heart disease prior to the last month of pregnancy
4. Left ventricular systolic dysfunction demonstrated by echocardiographic findings of decreased ejection fraction or shortening fraction
Women typically present with symptoms of heart failure including dyspnea, orthopnea, cough, palpitations, and chest pain. Findings on imaging studies are significant for cardiomegaly. Echocardiograph findings demonstrate an ejection fraction (EF) <45% or a shortening fraction <30%. Management consists of treating heart failure. Diuretics are used to reduce preload. Afterload reduction is achieved with use of a vasodilator. Digoxin is used if arrhythmias are identified. In women with severe cardiac dysfunction, anticoagulation may be recommended. Approximately 20% of patients have significant decline following diagnosis and require heart transplant. Partial recovery is seen in 30–50% of women, however, some degree of dysfunction remains. The remaining 30–50% of patients have significant improvement. Women who recover to a normal cardiac function and desire another pregnancy have a 20% risk of recurrence and low mortality rate. In contrast, women who do not return to normal cardiac function and undergo another pregnancy have a significant risk of recurrence and mortality. If the EF at diagnosis is <25%, 1 study found that at least 50% of these patients are subsequently placed on the cardiac transplant list. However, among patients whose EF was > 25% at diagnosis, none were placed on the cardiac transplant list during the next 3.4 ± 1.9 years. So although answer choices A and B do represent important prognostic factors for women with peripartum cardiomyopathy, the most important factor for future pregnancy counseling is whether or not the patient returned to normal cardiac function
Williams Obstetrics 23rd ed., Chapter 44: Cardiovascular Disease.
Creasy and Resnick’s Maternal-Fetal Medicine: Principles and Practice 7th ed., Chapter 52: Cardiac Disease.
