PROLOG: Obstetrics Flashcards
HPV Vaccine Administration
Why is pregnancy a hypercoagulable state? (4)
- Increased venous stasis
- Decreased venous outflow
- Compression of IVC by the uterus
- Decreased mobility
Which coagulation factor is decreased in pregnancy?
Protein S
What is the most common structural malformation associated with increased nuchal translucency?
Cardiac septal defects
A fetus identified has having an increased nuchal translucency and possible cardiac defect should be assessed with 1T Doppler of the DV and 2T Echo
How to diagnose fetal hemoglobinopathies?
Genetic testing: Mutations found in the parents can be used to identify the mutation in the fetus
The DNA-based tests can be performed using chorionic villi obtained by CVS at 10-12 weeks gestation or using cultured amniotic fluid cells obatined by amniocentesis after 15 weeks
What is APA associated with?
Increased risk of having a child with a single-gene disorder (achondroplasia, Apert syndrome, Crouzon syndrome)
Increased risk mainly due to an increased incidence of gene mutations that occur with spermatogenesis as a man ages
What is the MOST common aneuploidy associated with cystic hygroma in 2T?
Turner Syndrome (45X)
Other findings: coarctation of the aorta, shield-shaped chest, short stature
What is the MOST common cause of cystic hygroma in 1T?
Down Syndrome
Noonan syndrome associated findings
Pectus excavatum, pulmonary stenosis, short limbs
Edwards syndrome associated findings
Microcephaly, micrognathia, and short, overlapping digits
What complication has amnioinfusion been shown to reduce?
Cesarean delivery
What is the most common thrombophilic gene mutation in pregnancy?
Factor V Leiden heterozygote, responsible for 40% of all VTEs during pregnancy
When should zidovudine infusion begin prior to a cesarean delivery?
3 hours preoperatively in women with viral loads at time of delivery are greater than 1,000 copies/mL
ACOG Recommendations for HIV-Positive Patients
Which of the following is MOST associated with fetal surgery for repair of myelomeningocele?
Lower rates of VP shunts (40% vs 82%)
MRI Findings after Eclampsia
Induction of Labor for Fetal Demise with Previous C/S
What is the goal of internal rotation of the fetus?
Allow turning of the fetal head so that the occiput gradually moves toward the pubic symphysis and away from a transverse axis
What is the most common cause of maternal death in the first trimester?
Ectopic pregnancy
Risk factors for ectopic pregnancy
How is diagnosis of APS made?
Presence of at least 1 clinical criterion and at least 1 antibody that is persistently elevated 12 weeks apart
Antibiotic regimen for a woman with anaphylaxis to penicillin admitted for threatened PTL with intact membranes at 34 weeks’ gestation
Vancomycin, 20 mg/kg IV every 8 hours until delivery
Antibiotic regimen for GBS ppx based on allergy status
No PCN allergy
PCN allergy wth low risk for anaphylaxis
PCN allergy with high risk for anaphylaxis
Pregnancy is within GA range of 9+0 to 13+6 weeks, the pregnancy should be redated if the discrepancy between US and LMP dating is ___.
More than 8 days
Which hormone is responsible for leukorrhea of pregnancy?
Estrogen
Leukorrhea, or vaginal discharge, in pregnancy is usually a thick white discharge that is significantly increased during pregnancy because of the elevated estrogen levels. >> stimulates cervical gland hypertrophy >> produces copious amounts of thick white discharge
Which component of the BPP is the LAST to disappear in fetal distress?
Amniotic fluid volume
The BPP evaluates the acute and chronic well-beng of the fetus, and each component, except amniotic fluid volume, is controlled by a different part of the fetal brain. All elements, except amniotic fluid, evaluate the acute status of the fetus. The amniotic fluid assessment evaluates the chronic status of a fetus, and if reduced, represents shunting of fetal blood away from the kidneys and towards vital organs (i.e. brain).
The stepwise approach in PPH due to uterine atony
Which screening test has the HIGHEST detection rate for Down Syndrome?
Noninvasive prenatal testing with cell-free fetal DNA
The test can be used starting from 9-10 weeks
The fetal component of cell-free DNA is derived from placental trophoblasts that are released into maternal circulation from cells undergoing programmed cell death. >> this component known as fetal fraction.
Fetal fraction concentration can be affected by GA, BMI, maternal medication exposure, race, single/multiple gestation, etc…
This test is the only screening test to identify fetal sex and chromosomal aneuploidies.
Characteristics, Advantages, and Disadvantages of Common Screening Tests
PKU
AR condition in which there is a decreased activity of the hepatic enzyme phenylalanine hydroxylase (PAH).
Mother with PKU and pregnancy
The fetal heart and brain are especially vulnerable to high maternal levels of phenylalanine. Fetal levels of phenylalanine are higher than would be expected based on. maternal levels because phenylalanine is actively transported across the placenta.
In patients with PAH deficiency, the goal should be to normalize blood phenylalanine levels (<6 mg/dL) for at least 3 months prior to conception and to maintain blood phenylalanine levels at 2-6 mg/dL during pregnancy in order to optimize developmental outcomes for the fetus.
Consequences of Children Born to Women with PAH Deficiency on Unrestricted Diets
Pregnant women chronically infected with HCV can have uneventful pregnancies, however they can have a 20-fold increased incidence of _________.
Cholestasis
What is the BEST test to confirm diagnosis of pyelonephritis?
Urine Culture
Postpartum management of antibiotics in patients treated intrapartum for chorioamnionitis who undergo C/S
Receive 1 additional dose after delivery (including clindamycin) followed by discontinuation of the antibiotics
What is group prenatal care practice most associated with?
Increased rates of breastfeeding in the postpartum period
MOST common classification of neonatal herpes simplex virus infection
Infection of the skin, representing 45% of infections
Recurrent late decelerations: common causes and management
Diagnostic criteria for suspected intraamniotic infection
For patents with hyperthyroidism, when should PTU and Methimazole be used?
PTU: 1T, Methimazole: 2T
4 criteria necessary to diagnosis HIE
- Apgar score of less than 5 at 5 and 10 minutes after birth
- Fetal umbilical artery acidemia
- Multisystem organ failure
- Development of spastic quadriplegia or dyskinetic CP
Maternal and Fetal Contraindications to Tocolysis
Untreated hyperthyroidism can lead to SAB and ____.
Hydrops
PTU is linked to _______ and Methimazole is linked to ________.
- PTU: hepatotoxicity
- Methimazole: Aplasia cutus and esophageal/choanal atresia
Uncontrolled Maternal Hyperthyroidism (Fetal and Maternal Effects)
MOST likely benefit of delayed cord clamping in preterm infant?
Lower rate of necrotizing enterocolitis and IVH
What is an adequate CST?
At least 3 contractions persist for at least 40 seconds each in a 10-min period
What supplement is appropriate therapeutic adjunct to dietary restriction of foods that contain phenylalanine amoung pregnant women with PKU?
Sapropterin dihydrochloride (synthetic form of BH4)
Women with PAH deficiency are advised to achieve phenylalanine levels < 6 mg/dL for at least 3 months prior to conception and to maintain levels of 2-6 mg/dL during pregnancy.
Erb and Klumpke palsies
- Erb palsy: most common brachial plexus nerve injury (C5-C6), “waiter’s tip”
- Klumpke palsy: C8-T1
In cases of placenta previa, increasing number of prior C/S increases risk of placenta accreta as follows:
In a patient with a placenta previa and NO PRIOR cesarean sections, the risk for accreta is 3%.
Placental Abnormalities
Immediate postpartum IUD placement is contraindicated in:
A 34 yo G1 has hx of heterozygous Factor V Leiden deficiency. When is her risk for VTE greatest?
Postpartum, with the highest being the first week after delivery
At what gestational age can cell-free DNA testing be obtained?
Any time from 10 weeks until term
In which period during pregnany is a patient MOST likely to die from an amniotic fluid embolism?
During labor (70%), an additional 19% of cases occur during C/S, and 11% after vaginal delivery
How does a patient suffering from amniotic fluid embolism usually present?
Hypotension, hypoxia, coagulopathy
When mothers are using prescribed opiates for postpartum pain, what % of breastfed neonates will develop CNS depression related to this opioid use?
2-3%
Opioids are lipophilic drugs, weak bases, and have low molecular weight. These properties facilitate drug transfer into breast milk.
Among women with recurrent genital HSV, appoximately ___% can expect at least one recurrence during pregnancy
75%
Fetal blood volume at term
- Fetus Alone: 78 mL/kg
- Fetus + Placental Blood Volume: 125 mL/kg
Extra-hepatic manifestation MOST associated with chronic hepatitis C infection
Essential mixed cryoglobulinemia
Children born to women who smoke tobacco during pregnancy are at increased risk of: (5)
What are the amount of prepregnancy folic acid recommended for women at low risk and high risk for fetal neural tube defects, respectively?
400 mcg, 4 mg
Gestational Age and Radiation Dose on Radiation-Induced Teratogenesis
The rate of perinatal death is reduced by as much as 29% with interrogation of which fetal Doppler?
UA Doppler
Its use, inconjunction with standard fetal surveillance (NST, BPP) is associated with improved outcomes in fetuses in which fetal growth restriction has been diagnosed.
Increased impedance in the UA suggested that the pregnancy is c/b underlying placental insufficiency. Also, absent or reversed end-diastolic flow in the UA is associated with an increased frequency of perinatal mortality and can affect decision regarding timing of delivery in the context of fetal growth restriction.
When is the UA S/D ratio considered abnormal?
If it is >95th %ile for GA or if diastolic flow is either absent or reversed
What is MCA Doppler indicated for? Recommendations?
Fetal anemia
- Useful for detection of fetal anemia of any cause
- MCA = largest vessel of fetal cerbral circulation and carries about 80% of cerebral blood flow
- Fetal hypoxemia associated with growth restriction results in cerebral vasodilation, an early adaptive mechanism termed the brain-sparing effect
- MCA peak systolic velocity (PSV) is followed serially
- If velocity between 1.0 and 1.5 multiples of the median (MoM) and the slope is rising–such that the value is approaching 1.5 MoM–surveillance is generally increased to weekly Doppler interrogation
- If MCV PSV exceeds 1.5 MoM and GA < 34 or 35 weeks, fetal blood sampling should be considered and followed by fetal transfusion if needed
MOST common sign of uterine rupture in a patient undergoing TOLAC
FHT abnormality (acute fetal bradycardia)
What is the incidence of uterine rupture after 1 transverse C/S?
0.7%-0.9%
What is the most severe form of spina bifida?
Myelomeningocele, affects approximately 1 in 3,000 live births in the U.S.
Both the meninges and the spinal cord herniate through a defect in the spinal column and skin
The higher the lesion, the more nerves are affected and the poorer the prognosis
How long should therapeutic dose of LMWH be held before regional anesthesia is administered?
24 h
1 in 18,000 risk of spinal hematoma
How long should prophylactic dose of LMWH be held before regional anesthesia is administered?
12 h
A 28 yo G1 woman is started on a twice-daily therapeutic dose of LMWH during her pregnancy. What is the best target anti-Xa level when titrating the therapeutic dosage of LMWH in pregnancy?
0.6-1.0 units/mL measured 4 h after dosing
What is the BEST way to prevent wound infection in an obese patient (presents for R C/S)?
Antibiotics prior to skin incision
2 g cefazolin within an hour prior to incision; if she is > 120 kg, should receive 3 g cefazolin
The risk of surgical site infection after C/S delivery is 18%. Obese women have increased risk of wound infections due to (4):
- Increased inflammation
- Excess adipose tissue that is poorly oxygenated which extends wound healing
- Increased dead space
- Additionally, there are often larger incisions, prolonged operative times, and high blood losses in surgery with obese patients > increased risk of wound infection
Home Birth vs Hospital Birth
Home birth is associated with lower rates of maternal intervention but increased risks of perinatal death and neonatal neurological dysfunction
Absolute contraindications to home birth (3)
Malpresentation
Multiple gestation
Prior cesarean delivery
How does Roux-en-Y (RNY) gastric bypass cause nutritional deficiency?
RNY creates a small stomach pouch (restrictive) tha tconnects to the jejunum (malabsorption). This bypasses the duodenum and decreases the time that nutrients can be absorbed, which causes nutritional deficiencies.
Most common nutritional deficiencies after RNY
Protein
Iron
B12 (Cobalamin)
B9 (Folate)
Vitamin D
Calcium
During a C/S, an injury to the base of the bladder is made, immediately adjacent to the right ureteral orifice. What is the next best step?
Retrograde stent placement
The bladder should be repaired once the obstetrical portion of the procedure is complete. Bladder injuries should be repaired in a two-layer closure (if at the dome).
This injury is at the base. When immediately next to a ureteral orifice, place retrograde stent prior to closure. Will prevent kinking or occlusion of the ureter’s base during closure and the healing process.
Current guidelines recommend proceeding with perimortem C/S delivery after ____ minutes of CPR has failed to achieve spontaneous return of circulation, with a goal being a delivery by 5 minutes.
4
Maternal outcomes are not thought to be worsened following perimortem cesarean, and may be improved as evacuation of the gravid uterus can improve venous return to the heart.
Patients with GDM should check fasting and either 1or 2 hour postprandial blood glucose levels.
Goal
Causes of PPH and % cases of PPH (approximate)
What are the serum lab test components in a FTS for fetal chromosomal abnormalities?
PAPP-A, free or total bHCG
What is the first-trimester screen?
2-part screening test, which involves maternal serum labs and U/S to assess nuchal translucency
FTS has 82-87% detection rate for T21
The labs for FTS are PAPP-A and free or total bHCG
What are the maternal serum labs tested in a quad screen?
MSAFP, hCG, unconjugated estriol, and inhibin A
Performed during 2T, between 15 to 22 weeks, and has detection rate of 81% for T21
Rubin maneuver
- McRoberts
- Suprapubic
- Delivery of posterior arm
- Rubin maneuver: Place a hand in the vagina and on the back surface of the posterior fetal shoulder, then rotate the shoulder anteriorly towards the fetal face. This may be used instead of delivery of the posterior arm or after failure to delivery the posterior arm
What is the approximate risk of uterine rupture in women with one previous low-transverse cesarean delivery who are undergoing IOL using prostaglandins?
Up to 2.2%
Criteria for outlet forceps (5)
Criteria for Low Forceps
Who should get CL screening?
Women who have a current singleton pregnancy and a history of preterm birth
Which hemoglobin is deficient in a patient with beta-thalassemia?
Hemoglobin A (2 alpha-globin chains and 2 beta-globin chains)