MFM Flashcards
At discharge, a full term infant’s examination reveals that the infant has a weak cry, hypotonia, and poor oral feeding with difficulty swallowing. Because the infant’s mother has myasthenia gravis, there is a high probability that these symptoms are attitubable to transient neonatal myasthenia gravis. By what age is this infant expected to completely recover? By what do hours of age dosymptoms typically occur?
By 2 months of age. MG is a chronic autoimmune disease leading to progressive fatigure and weakness involving facial, pharyngeal, and respiratory muscles. 90% with MG has antibodies(IgG) to acetylcholine receptors. 10-20% of neonates born to women with MG will develop neonatal MG as a reults of transplacental transfer of maternal Ach receptor antibodies. Neonatal MG manifests as in the question. These symptoms tyically occur by 72 hours of age with a mean duraiton of 18 days, but may be as long as 15 weeks. There is excellent recovery with 90% by 2 months, the remaining 10% by 4 months. MFM Q1
A neonate presetns with depressed nasal bridge, nail hypoplasia, seizures, and stippled bone epiphyses. These are findings are most likely a result from intrauterine exposure to which teratogen?
Warfarin. Intratuterine exposure during 6-12 weeks gestation leads to clinical manifestations in25% of neonates, as listed in the question. Infants may alos have low birthweight, seizure activity, and cognitive disabilities. If intrauterine exposure occurs after the 12th week, there is less of an impact on the fetus. MFM Q2
A 34 year old mother has a an elevated serum alpha-fetoprotein (AFP) at 18 weeks. You counsel her that the next most appropriate step would be: A. Amniocentesis to measure AFP B. Amniocentesis to obtain a karyotype C.Fetal ultrasound D. Plasma protein A (PAPP-A) screening E. Repeat beta hCG serum testing
C. Fetal Ultrasound to determine gestationa age. If a pregnant woman has an elevated AFP, fetal ultrasound is recommended. If gestational age has been underestimated resulting in a normal AFP or multiple gestations are identified, routine care is suggested. IF the US confirms the gestational age and there is no fetal abnormalities a/w and elevated AFP, genetic counseling is recommended and amniocentesis may be considered to measure amniotic AFP and obtain a karyotype. If a fetal abnormality is detected by US, care is tailored to the specific finding. MFM Q3
What is included in a quadruple screen and which of the 4 tests is the least sensitive?
While a quadruple screen is done at 14-20 weeks (16 weeks is optimal) and consists of AFP, maternal unconjugated estriol, and maternal beta- hCG and inhibin A, maternal AFP is the least sensitive of the 4 tests. If a pregnant woman has an elevated AFP, fetla ultrasound is recommended.
You are called STAT to a C-section secondary to severe vaginal bleeding a/w placental abruption. The infant emerges vigorous, crying, and pink. As you review the maternal history, you find a history of substance abuse. Which of the drug of abuse is associated with placental abruption? What other problems can this drug of abuse cause in the fetus?
Cocaine. Intrapartum exposure to cocaine can increase the risk of stillbirths, placental abruption, skull abnormalities, cutis aplasia, porencephaly, ileal atresia, cardiac anomalies and urogenital anomalies. MFM Q 4
Name the drug of abuse is a/w the following: increase the risk of stillbirths, placental abruption, skull abnormalities, cutis aplasia, porencephaly, ileal atresia, cardiac anomalies and urogenital anomalies.
cocaine MFM Q4
You are called to a delivery due to late fetal heart rate decelerations. What is the most physiologic cause of this pattern? Head compression, placental compression, umbilical cord compression, or uteroplacental insufficiency?
uteroplacental insufficiency MFM Q 5
What is the pathophysiology behind late decelerations?
uteroplacental insufficiency –>fetal hypoxia –>chemoreceptor response –>enchanced alpha adrenergic activity –> fetal hypertension –> baroreceptor response –> parasympathetic response –> late deceleration; uteroplacental insufficiency –> fetal hyppxemia –> myocardial depression –> late deceleration MFM Q5
What is the mechanism behind early decelerations
fetal head compression –> pressure on the head –> changes in cerebral blood flow –> vagal decelerations –> early decelerations MFM Q5
What is the mechanism behind variable decelerations
umbilical cord compression –> decrease in fetal heart rate by either a baroreceptor or chemoreceptor vagal response or fetal myocardial compression MFMQ5
What is the prevalance of a single umbilical artery (2 vessel cord)?
< or = 1% MFM Q6
This anomaly is 3-4x more common in twins compared with singletons and may be associated with urogenital tract or cardiac anomalies
single umbilical artery MFM Q6
This medication is a prostaglandin synthase inhibitor that is adminitster to pregnant woman as a tocolytic. It can lead to presistent pulmonary HTN, renal insufficiency, ileal perforation, or necrotizing enterocolitis in the neonate and thus prolonged maternal use is not recommended.
Indomethicin MFM Q8
This medication administered to pregnant women can increase the risk of congenital heart defects in the neonate. Case reports reveal other risks such as fetal goiter and premature birth, as well as neonatal hypotonia, arrythmias, seizures, and diabetes insipidus.
lithium MFM Q8
This is a tocolytic medication that decreases uterine contractility by decreasing acetylcholine release from the neuromuscular junction and by acting as a calcium antagonist. Neonatal complications can include a decreased respiratory rate, decreased peristalsis, hypotension, and/or hypotonia
magnesium sulfate MGM Q8
This is a calcium channel blocking agent used for tocolysis because it decreases uterine contractility as a result of transmembrane calcium influx. Prolonged use can lead to uteroplacental insufficiency.
Nifedipine MFM Q8
This is a beta-2 agonist that binds to beta-2 receptors of the uterine myometrium, activating adrenyl cyclase, which converts ATP to cyclic adenosine monophosphate. This decreaes intracellular calcium with an associated decrease in uterine contractility. While fetal tachycardia can be associated with administration of this medication to the mother, it has minimal effects on the neonate.
Terbutaline MFM Q8
This is one of the most common complications of pregnancy affecting 5-10% of pregnant women. It can occur in a women that is previously healthy or be superimposed on a woman with a chronic hypertensive disorder
pre-eclampsia MFM Q9
Define pre-eclampsia
hypertension developing after 20 weeks gestation that is associated with proteinuria MFM Q9
Name risk factors for Pre-E
primaparity, twin gestation, chronic HTN, diabetes, obesity MFM Q9
Define severe pre-eclampsia
Hypertension developing after 20 weeks gestation that is associated with proteinuria and one or more of the following: BP > or = to 160/110, proteinuria > or = to 5 grams in 24 hours or > or = 3+ protein in two urine samples, changes in vision, headaches, oliguria, any manifestations of HELLP syndrome, pulmonary edema, fetal growth restriction MFM Q9
Define HELLP
hemolysis (elevated LDH), elevated liver enyzmes, low platelets MFM Q9
What are common symptoms of NAS?
CNS (tremors, agitation, hyperactive moro reflex, abnormal tone) GI (diarrhea, poor feeding, excessive sucking) and autonomic disturbances (temperature instability, sneezing, skin color changes) MFM Q 12
What is the first line management of NAS?
morphine; if there are additional CNS symptoms or the mother had polysubstance abuse, phenobarbital may be useful MFM Q 12
A baby is born with the following features: dysmorphic facies (short palpebral fissures, thin vermillion border of the upper lip, smooth philturm), microcephaly, and growth restriction. What substance did she consume during her pregnancy?
Alcohol. It affects cardiac (VSD, Tetralogy of Fallot with pulmonary stenosis) and CNS abnormalities. MFM Q 13
What is the occurance of FAS?
0.5-2 per 1000 live birth in the US with disproportionately higher rates among African American and Native Americans MFM Q13
What are possible mechanisms behind the teratogenesis of alcohol on the fetal brain?
- an apoptotic effect via blockade of NMDA glutamate receptors and activation of gamma-aminobutyric acid (GABA) A receptors. 2. reduction in the fetus’ ability to respond to free radical damage 3. direct inhibition of sonic hedgehog gene signaling MFM Q13
A 45 year old womam had a successful in vitro fertilzation resulting in twin gestaion. In which of the following types of twin gestation is a twin to twin transfusion MOST LIKELY to occur? Dichorionic diamniotic, monochorionic diamniotic, monochorionic monoamniotic
Monochorionic diamniotic. Twin to twin transfusion occurs in only 5-15% of monochorionic diamniotic twins even though 85% of these twins have vascular anastomoses. Twin to twin can occur in monochorionic monoamniotic twins but occurs less frequently. Monozygotic twins that are dichorionic diamniotic are not a risk for twin to twin. MFM Q 14
This occurs when there is placental vascular anastomoses (typically deep and ateriorvenous connections) leading to acute and chronic transfer of blood from one twin to another
twin to twin transfusion MFM Q 14
Approximately 80% of fetal mineral accretion occurs between 25 and 40 weeks. Explain how this happens
Because placental syncytioblasts have a relatively low calcium concentration, facilitative diffusion fom the pregnant woman to the placenta can occur. Next an ATP dependent calcum pump tranfers calcium from the basal syncytial surface to the fetus. These processes enale to the fetus to be hypercalcemic relative to the mother, particularly in the thrid trimester. MFM Q 15
_____ fetal calcitonin concentration inhibits fetal bone resorption
High MFM Q 15
Does estrogen increase or decrease the fetal mineral accretion
increases MFM Q15
A pregnant woman at 27 weeks is admitted with preterm labor and gets one course of antenatal steroids. When determining the risks and benefits of antenatal corticosteroids, there has been proven reduction in all the following except: infant mortality, PDA, respiratory distress, and severe IVH
PDA. Studies have shown reduction in infant mortality, respiratory distress, and and IVH. PDA has not been impacted. Studies have not consistently shown a reduction in NEC or CLD between those who received steroids and those who didn’t. MFM Q 16
A 28 yo woman has a fetal survey at 18 weeks gestation and fetal US demonstrates choroid plexus cysts. There are no other radiographic findings. What is the prevalance of choroid plexus cysts? <1%, 5%, 10%, 20%, 30%
<1%. Choroid plexus csyts are detected by fetal US in 0.5% of fetuses as early as 11 weeks gestation and usually disappear by 26 weeks. Ususally isolate but may be a/w trisomy 18. MFM Q17
What is the cause of choroid plexus cysts?
neuroepithelial folds that are filled with CSF and debris. MFM Q 17
What is the pH of amiontic fluid?
pH> /= 6.5 (7-7.5) You can use nitrazine paper as an indicator. MFM Q18
What is the normal pH of vaginal fluid?
4.5-5.5 False positives can occur with blood, semen, and BV while false negatives can occur if there is an inadequate amount of vaginal fluid. MFM Q 18
A pregnant woman migrates from Botwana and does not have an vaccines. Which vaccines, if any, are contraindicated in pregnant women?
Measles, mumps, rubella, and varicella contain live viruses and therefore contraindicated in pregnancy unless there is a high probability of exposure and disease. MFM Q19
What vaccines may be administered during pregnancy but preferably in the 2nd or 3rd trimester due to the risk of teratogenicity?
pneumococcal, meningococcal, hep B, and inactivated polio MFM Q19
What vaccines are recommended for pregnant women?
tetanus, diptheria, and inactivted infuenza MFM Q19
Are metformin and glyburide safe to use for gestational diabetes?
Yes. Insulin is first line but metformin and glybruide both cross the placenta but studies have shown no increase in congenital anomalies with the use of Metformin. The risk of neonatal hypoglycemia and macrosomia is higher with glyburide compared to insulin. MFM Q 20 (note- answer in book is wrong)
True or false- women with type 1 and type 2 DM have significantly higher risk for congenital malformations compared to women with gestational diabetes
True. The risk of congenital malformations approaches 20-25% when HgbA1c values approach 10. MFM Q21
Which of the following types of twins poses the greatest risk for cord entanglement? Dichorionic diamniotic, monochorionic diamniotic, monochorionic monoamniotic
Monochorionic monoamniotic MFM Q 22
What is the incidence of dizygotic twins and how are these babies formed?
2/3 of all twins are dizygotic. Formed by fertilization of 2 eggs but 2 sperm leading to fraternal twins; dizygotic twins have 2 placentas but if implantations sites are near, the placentas may fuse MFM Q 22
What is the incidene of monozygotic twins and how are these babies formed?
1 per 250 or 1/3 of all twins; 1 egg is fertilized by 1 sperm which splits during the first 2 weeks of development; 25-30% are dichorionic diamniotic, 70-75% are monochorionic diamniotic, and 1-2% are monochorionic monoamniotic MFM Q 22
What are the 3 types of monozygotic twins and what is the timing of splitting of each of these types?
A. dichorionic diamniotic: early division before day 3; before the chorion is completely formed B. monochorionic diamniotic: division between 3-8 day; after the chorion is formed and before the amnion is completely formed. C. monochorionic monoamniotic: later division (between 8-13 days); after both the chorion and amnion have formed; if splitting day 13-15 (ie after the chorion, amnion, and embryonic plate formed) it may lead to conjoined twins MFM Q22
What are the in utero risks for monochorionic diamniotic twins?
increased risk for twin-twin transfusion; greater chance of growth discordance MFM Q 22
What are the in utero risks to monochorionic monoamniotic twins?
cord entanglement a/w a high mortality rate; greater chance of growth discordance; risk of acardia (rare complication where one twin has no heart or non-functioning rudimentary cardiac tissue; the twins survive because of placental vascular anastomoses; the pump twin is at risk of cardiac failure with 50% mortality) MFM Q 22
When are pregnant mom’s screened for gestational diabetes?
24-28 weeks MFM Q23
What is the difference in platelet count and affect on the neonate between maternal ITP and gestational thrombocytopenia?
In both conditions, neonates are unaffected with maternal ITP., the maternal platelet count is usually <70,000 and in gestationa thrombocytopenia and maternal platelet count is usually > 70,000. MFM Q 24
What is the pathophysiology behind maternal ITP?
ITP occurs in pregnant women when antibodies directed against maternal antigens on maternal platelets are cleard by the reticuloendothelial system, causing maternal thrombocytopenia (platelets < 70,000). Neonates aren’t affected. (MFM Q 24)
Measlses and mumps are both paramyxoviruses. Which one increases the risk of first trimester spontaneous abortion?
Mumps. There is no increased risk of spontaneous abortions with measles. MFM Q25
Which of the following is the dominant thyroid hormone during fetal life? Free thyrozine (T4), reverse triiodothryonine (rT3), and triiodothronine (T3)
rT3. The fetus converts throxine (T4) to rT3 bydeiodinase (D3), an enzyme that is present in placental and fetal tissues. D3 inactivates most of maternal T4. Thus rT3 is the dominant thyroid hormone during fetal life. Fortuntely, T4 concentrations in the fetal rain are presered because of local action of intracellular deiodinase (D2). MFM Q 26
