High risk Obstetrics Flashcards
Which one of the following is FALSE regarding nitric oxide (NO)?
a. Nitric oxide contracts vascular and uterine smooth muscle
b. Nitric oxide acts via cGMP
c. Nitric oxide synthetase (NOS) inhibitors do NOT increase uterine contractile activity in animal studies, suggesting no role for nitric oxide in maintaining uterine quiescence
d. Nitric oxide is released by immune cells in response to inflammatory stimuli
a. Nitric oxide contracts vascular and uterine smooth muscle
O
Causes smooth muscle RELAXATION so dilation
Thyroid hormone
a. Must be present for the fetus to grow normally
b. Is active in the fetus as rT3
c. Is necessary for shivering thermogenesis, but not non-shivering
d. Has increased concentrations after birth because of a TSH surge
d. Has increased concentrations after birth because of a TSH surge
Which of the following is NOT a feature of placenta sulphatase deficiency?
a. Abnormal serum screening for Down Syndrome
b. Low bishop score at term
c. Icthyosis
d. Autosomal recessive inheritance
e. Prolonged pregnancy
d. Autosomal recessive inheritance
O
X-linked ichthyosis = scaly baby
X-linked inborn error of metabolism
placental SSD is associated with pregnancies progressing beyond 40 weeks gestation, with less than a third of the pregnancies affected by placental SSD laboring spontaneously.
The majority of reported cases ended in induction of labor and/or cesarean delivery.
increased rate of failure to respond to endogenous or intravenous oxytocin and failure of cervical dilatation.
During placental development
a. Complete fetoplacental circulation is developed by 5-6 weeks post conception
b. Endovascular migration by cytotrophoblasts proceeds in two waves that are complete by 8-10 weeks gestation
c. Uteroplacental blood flow is 200-250mL/min at term
d. Fetal blood flows to the placenta through paired umbilical arteries and a vein, and reaches 350-400mL/min average
a. Complete fetoplacental circulation is developed by 5-6 weeks post conception
Which of the following statements concerning monozygotic twins is NOT TRUE?
A. Approximately 30% of monozygotic twins are diamniotic dichorionic
B. Approximately 25% of twins are monozygotic
C. Placental vascular anastamoses are present in approximately 95% of monochorionic twins
D. Splitting of the embryo before day 8 post-conception will result in dichorionic twins, splitting after day 8 results in monochorionic twins
E. Monochorionic twins occur approximately 1 in 400 births.
D. Splitting of the embryo before day 8 post-conception will result in dichorionic twins, splitting after day 8 results in monochorionic twins
O
DCDA by day 3
MCDA between days 4-7
MCMA between days 8-12
Conjoined after day 13
Which is autosomal recessive?
a. Huntingtons
b. Marfans
c. Cystic fibrosis
d. Adult onset PCKD
c. Cystic fibrosis
A man with an X linked recessive condition has a child to a normal homozygous woman. They have two children. The chance that BOTH children have the disease is
a. 0
b. 1/8
c. 1/4
d. ½
a. 0
Amniocentesis reveals a karyotype 47XXY. Which of the following descriptions is INACCURATE for an adult with this condition?
a. Serious intellectual disability
b. Tall stature
c. Elevated FSH
d. Female fat distribution
a. Serious intellectual disability
Which is FALSE regarding the hormone relaxin in pregnancy?
a. It is structurally related to growth hormone
b. The corpus luteum is the most important source of circulating relaxin
c. The absence of relaxin doesn’t seem to have clinical sequelae
d. Recombinant human relaxin is not an effective cervical ripening agent
a. It is structurally related to growth hormone
O
Crossing over of chromosomes occurs during
a. Metaphase 1
b. Mitotic prophase
c. Meiotic prophase 1
d. Meiotic prophase 2
c. Meiotic prophase 1
During gestation, amniotic fluid
a. Osmolality increases to become isosmotic with plasma at term
b. Becomes progressively hyposmolar, with lower concentrations of sodium and potassium chloride than in maternal plasma
c. Is formed in late gestation, with almost equal contribution from fetal urine and lung liquid
d. Volume is regulated by fetal swallowing which commences after keratinisation of fetal skin
e. Volume progressively increases, reaching a maximum volume of 750mL at 40weeks
b. Becomes progressively hyposmolar, with lower concentrations of sodium and potassium chloride than in maternal plasma
O
Max volume ~800mL usually and peaks at ~34weeks
Main determinant is fetal UO
Alpha feto protein concentration in the amniotic fluid will be elevated in each condition EXCEPT
a. A dead fetus
b. A fetus with spina bifida occulta
c. A fetus with a myelomeningocele
d. Contamination of amniotic fluid with fetal red cells
e. A fetus with exomphalos
b. A fetus with spina bifida occulta
O
- no increase in occulta, all other forms it will. Amniotic fluid will be elevated as well as maternal serum.
Which is FALSE?
a. Base deficit is defined as the bicarbonate ion concentration below normal
b. After bicarbonate, Hb is the next most important acid base buffer for the fetus
c. Increase in the anion gap is commonly seen in Diabetic Ketoacidosis
d. The fetal oxygen haemoglobin dissociation curve is shifted to the right compared to an adult
d. The fetal oxygen haemoglobin dissociation curve is shifted to the right compared to an adult
LEFT shift
Higher affinity due to HbF
The mode on inheritance of cystic fibrosis is
a. Autosomal recessive
b. Autosomal dominant
c. Sex linked recessive
d. Sex linked dominant
e. Polygenic
a. Autosomal recessive
Which one of the following statements concerning TTTS is LEAST CORRECT
a. In stage 1 TTTS there is polyhydramnios, stage 2 empty bladder of the donor twin, stage 3 absent/reversed umbilical arterial doppler waveform, stage 4 fetal hydrops, stage 5 fetal death of one or both twins
b. The presence of increased arterial-arterial anastomoses on the surface of the placenta is associated with an increased risk of TTTS
c. Survival in TTTS is approximately 30% untreated, 50% if treatment is available
d. Serious disability still occurs in approximately 10% of TTTS survivors treated with laser coagulation (where both twins are survivors)
e. Increased nuchal translucency at 11-14 weeks gestation is associated with an approximately 30% sensitivity and 30% PPV in detecting subsequent TTS
f. The incidence of TTS in monochorionic twin pregnancies is approximately 15%
b. The presence of increased arterial-arterial anastomoses on the surface of the placenta is associated with an increased risk of TTTS
O
Assoc with LOWER risk TTTS - thought to be protective. MCMA higher rates of A-A anastomosis and lower rates TTTS
A 28yo G2P1 is referred at 36+2 weeks gestation with BP 150/100, proteinuria, headache, and upper abdominal discomfort. The AST is 100. She has no history of pre-eclampsia in the previous pregnancy. Your NEXT step is:
a. Induction of labour as soon as possible
b. Discharge patient home and ask the LMC to check the blood pressure next week
c. Arrange a growth scan
d. Arrange BP in 48 hours along with CTG and repeat bloods.
a. Induction of labour as soon as possible
In advising a woman on whether she should continue the pregnancy to 42 weeks or be induced at 41 weeks, which of the following is FALSE?
a. The Canadian randomised trial (Hannah et al) showed that induction of labour increases the likelihood of Caesarean section
b. Waiting is likely to be associated with a higher perinatal mortality
c. If the Bishop score is <5, intravaginal prostaglandins will be recommended
d. An ultrasound will be indicated if she elects to wait
a. The Canadian randomised trial (Hannah et al) showed that induction of labour increases the likelihood of Caesarean section
O
Each of the following statements concerning Multifetal Reduction is true EXCEPT
a. Reducing triplets to twins at 10-14 weeks gestation is associated with a subsequent rate of miscarriage of both twins of approximately 8%
b. Reducing triplets to twins at 10-14 weeks gestation is associated with an increase in mean gestation at delivery
c. Reducing triplets to twins at 10-14 weeks gestation is not associated with a reduction in perinatal mortality
d. Reducing triplets to twins at 10-14 weeks gestation is associated with a reduction in the likelihood of having a handicapped survivor
e. KCl and xylocaine are alternative agents to use for Selective Feticide
c. Reducing triplets to twins at 10-14 weeks gestation is not associated with a reduction in perinatal mortality
Correct answer in official MCQ Feb 2011 and RANZCOG online questions
2008 answer:
b. Reducing triplets to twins at 10-14 weeks gestation is associated with a reduced likelihood of taking home one live baby
A 20yo G1P0 has DCDA twins diagnosed at 18 weeks. All of the following should normally form part of the subsequent management of this pregnancy EXCEPT:
a. Ultrasound at 26-30 weeks, and again at 34-35 weeks
b. Iron and folic acid supplementation
c. Prophylactic corticosteroids with betamethasone due to the risk of preterm labour
d. The need to present early if painful uterine contractions occur prior to 34 weeks
c. Prophylactic corticosteroids with betamethasone due to the risk of preterm labour
O
Which is false regarding atosiban?
a. RCT’s show similar efficacy to beta sympathomimetics in delaying delivery by 48 hours
b. RCT’s show better maternal tolerance of side effects in comparison to beta sympathomimetics
c. RCT’s suggest that atosiban has a higher perinatal mortality than salbutamol when used at extremely premature gestations
d. RCT’s suggest that atosiban has similar efficacy to beta sympathomimetics in the prevention of preterm birth
e. Atosiban is an inhibitor of oxytocin secretion by the neurohypophysis
e. Atosiban is an inhibitor of oxytocin secretion by the neurohypophysis
O
Tocolytic agent
The oxytocin receptor antagonist, atosiban, may be used for the inhibition of uncomplicated premature labour between 24 and 33 weeks of gestation. Atosiban may be preferable to a beta2 agonist because it has fewer adverse effects.
Factors that are associated with an incompetent cervix include all of the following EXCEPT
a. In utero exposure to DES
b. Cervical laceration
c. Cervical infection
d. Cervical cone biopsy
c. Cervical infection
O
DES causes reproductive tract abnormalities to women exposed in utero
- miscarriages, PTB, ectopic pregnancy
A 22yo woman at 32 weeks presents with painful uterine contractions and 200mL APH. Fundus is smaller than dates, she has pain between contractions. If this is due to drug exposure in utero, the likely culprit is
a. Heroin
b. Cocaine
c. Caffeine
d. Cannabis
e. Alcohol
b. Cocaine
O
Which of the following congenital malformations below is MOST LIKELY to be associated with oligohydramnios?
a. Duodenal atresia
b. Unilateral ureteropelvic junction obstruction
c. Gastroschisis
d. Posterior urethral valves
d. Posterior urethral valves
In placebo-controlled RCT’s, beta sympathomimetics have been shown most convincingly to:
a. Lower risk of preterm birth
b. Lower risk of birth within 48 hours
c. Lower perinatal mortality
d. Cause higher birthweight
b. Lower risk of birth within 48 hours