WebPath 4 Pediatric Perinatal(with Accurate answers)
A healthy 19-year-old primigravida is in the 12th week of an uncomplicated pregnancy when she
develops vaginal spotting of blood and mild cramping abdominal pain. On physical examination
she is afebrile. There is minimal vaginal bleeding but no exudate. A spontaneous abortion occurs
a day later. Which of the following conditions is most likely to produce these findings? correct
answers Chromosomal abnormality. Abnormalities such as trisomy 16 and tetraploidy, not
typically seen in livebirths, are found in many first trimester abortuses. Many first trimester
pregnancy losses relate to fetal, not maternal, problems.
A 26-year-old G4 P3 woman gives birth via normal spontaneous vaginal delivery at term. The
infant has Apgar scores of 9 and 10 at 1 and 5 minutes and weighs 2950 gm. The placenta is
delivered 10 minutes later and weighs 500 gm. Examination of the placenta reveals that the
umbilical attachment to the infant is 100 cm long. Which of the following additional
abnormalities is most likely to have been observed at the time of delivery? correct answers
Nuchal cord. A long umbilical cord from increased fetal movement can more easily wrap around
the fetus. In most cases there is no fetal compromise, but a nuchal cord could interfere with
delivery, or the fetal blood supply could be compromised.
A 19-year-old woman is G2 P1. Her previous gestation resulted in a normal term birth at home.
Her current pregnancy results in the birth of a 2990 gm baby at 35 weeks. At birth the infant
appears hydropic and icteric, but no congenital anomalies are noted. The baby's hemoglobin is
8.5 g/dL. The placenta is also hydropic, but microscopic examination of the placenta shows no
inflammation of either fetal membranes or placental villi, and there is no meconium staining.
Which of the following problems in the mother is the most likely explanation for the subsequent
findings in the infant? correct answers Antibodies crossing the placenta. The hydrops and the
icterus are findings of erythroblastosis fetalis, which is most often due to Rh blood factor
differences between mother and fetus, but there are other RBC antigens that could be involved.
The mother is exposed to a fetal RBC antigen in a previous pregnancy and develops antibodies
that cross the placenta in subsequent pregnancies to cause destruction of fetal red blood cells,
leading to anemia and icterus.
No fetal movement has been felt for the past day by a 25-year-old gravida 3 para 2 woman in her
39th week of pregnancy. Prior to that time, the pregnancy was uncomplicated. The baby is
stillborn upon vaginal delivery a day later, after rupture of membranes occurs. Microscopic
examination of the placenta reveals marked acute chorioamnionitis. Which of the following
infectious agents is most likely responsible for these findings? correct answers Group B
streptococcus. The acute inflammation suggests a bacterial infection, and group B Streptococcus
(GBS), which can colonize the vagina, is a common cause. GBS can elaborate a factor that
dampens C5a mediated neutrophil chemotaxis, but neutrophils are still present.
A 17-year-old primigravida has noted no fetal movement during her pregnancy, and she is now
at 18 weeks gestation. Oligohydramnios is noted on fetal ultrasound scan, making it difficult to
visualize fetal internal organs, but the size of the baby appears consistent for 18 weeks
gestational age. Following a counseling session with their physician, the parents decide to
proceed with prostin induction for a medically indicated termination of pregnancy. Autopsy
, reveals no external anomalies upon examination of the stillborn male. Which of the following
findings is most likely to explain this deformation sequence? correct answers Urethral atresia.
The oligohydramnios is part of a deformation sequence resulting in pulmonary hypoplasia. The
urethral atresia precludes output of fetal urine. The atresia should increase the size of the fetal
bladder, but in this case imaging was difficult.
A 32-year-old G2 P1 woman has an uncomplicated vaginal delivery of a 30 week gestational age
male infant. Apgar scores of 5 and 7 at 1 minute and 5 minutes are recorded at the time of birth.
The baby then begins to exhibit increasing respiratory difficulty in the next hour, culminating in
the need for intubation and mechanical ventilation. Which of the following laboratory tests
during gestation is most likely to predict the complication observed in this infant? correct
answers Lamellar body count on amniotic fluid. There is fetal lung immaturity leading to hyaline
membrane disease with neonatal respiratory distress syndrome. Tests for fetal lung maturity
(usually reached by 35 to 36 weeks when there is sufficient production of surfactant by type II
pneumocytes in fetal lung; intracellular surfactant is contained within lamellar bodies), including
the older L:S ratio, as well as lamellar body count, phosphatidylglycerol, and fluorescence
polarization (fpol). These can be done on amniotic fluid.
33-year-old G3 P2 woman gives birth at 38 weeks gestation to a male infant who weighs 2270
gm. Apgar scores are 7 and 9 at 1 and 5 minutes after birth. This neonate has no external
anomalies present on physical examination except that he appears somewhat disproportionate,
with a head size more appropriate for gestational age than body size. The pregnancy was
uncomplicated. Which of the following conditions is most likely to account for these findings?
correct answers Maternal tobacco use. Smoking is the most common cause for low birth weight
babies in developed nations. From maternal causes, the head size tends to be preserved in the
fetus. Such babies have more complications following birth.
A genetic counselor elicits the history that three adult males and one adult female in a family of
10 over 3 generations have an intellectual disability, the males more severely so. Physical
examination of these affected males reveals no major morphologic anomalies, though their testes
appear to be slightly enlarged, without mass lesions present. These males have been healthy,
without a history of major illnesses. Which of the following genetic abnormalities is the most
likely etiology for these findings? correct answers Fragile X syndrome. This is the most common
cause of familial intellectual disability, with karyotype 46 fra(X)Y. It is due to a 'triple repeat'
mutation of a sequence of three nucleotides involving the FMR-1 gene that codes for FMRP that
is found in cell cytoplasm, most prominently in brain and gonads.
A 21-year-old G2P1 woman feels that she is large for dates. She has felt fetal movement for the
past week. She has a screening fetal ultrasound scan performed at 16 weeks gestation that reveals
markedly increased amniotic fluid (polyhydramnios). Which of the following fetal abnormalities
is most likely to cause this finding? correct answers Small intestinal atresia. Anomalies that
interfere with fetal swallowing are most likely to produce an excess of amniotic fluid.
Esophageal and intestinal atresias do this. Amniotic fluid formed in the kidneys is excreted into
the amniotic cavity, then swallowed and resorbed in the gastrointestinal tract.
A healthy 19-year-old primigravida is in the 12th week of an uncomplicated pregnancy when she
develops vaginal spotting of blood and mild cramping abdominal pain. On physical examination
she is afebrile. There is minimal vaginal bleeding but no exudate. A spontaneous abortion occurs
a day later. Which of the following conditions is most likely to produce these findings? correct
answers Chromosomal abnormality. Abnormalities such as trisomy 16 and tetraploidy, not
typically seen in livebirths, are found in many first trimester abortuses. Many first trimester
pregnancy losses relate to fetal, not maternal, problems.
A 26-year-old G4 P3 woman gives birth via normal spontaneous vaginal delivery at term. The
infant has Apgar scores of 9 and 10 at 1 and 5 minutes and weighs 2950 gm. The placenta is
delivered 10 minutes later and weighs 500 gm. Examination of the placenta reveals that the
umbilical attachment to the infant is 100 cm long. Which of the following additional
abnormalities is most likely to have been observed at the time of delivery? correct answers
Nuchal cord. A long umbilical cord from increased fetal movement can more easily wrap around
the fetus. In most cases there is no fetal compromise, but a nuchal cord could interfere with
delivery, or the fetal blood supply could be compromised.
A 19-year-old woman is G2 P1. Her previous gestation resulted in a normal term birth at home.
Her current pregnancy results in the birth of a 2990 gm baby at 35 weeks. At birth the infant
appears hydropic and icteric, but no congenital anomalies are noted. The baby's hemoglobin is
8.5 g/dL. The placenta is also hydropic, but microscopic examination of the placenta shows no
inflammation of either fetal membranes or placental villi, and there is no meconium staining.
Which of the following problems in the mother is the most likely explanation for the subsequent
findings in the infant? correct answers Antibodies crossing the placenta. The hydrops and the
icterus are findings of erythroblastosis fetalis, which is most often due to Rh blood factor
differences between mother and fetus, but there are other RBC antigens that could be involved.
The mother is exposed to a fetal RBC antigen in a previous pregnancy and develops antibodies
that cross the placenta in subsequent pregnancies to cause destruction of fetal red blood cells,
leading to anemia and icterus.
No fetal movement has been felt for the past day by a 25-year-old gravida 3 para 2 woman in her
39th week of pregnancy. Prior to that time, the pregnancy was uncomplicated. The baby is
stillborn upon vaginal delivery a day later, after rupture of membranes occurs. Microscopic
examination of the placenta reveals marked acute chorioamnionitis. Which of the following
infectious agents is most likely responsible for these findings? correct answers Group B
streptococcus. The acute inflammation suggests a bacterial infection, and group B Streptococcus
(GBS), which can colonize the vagina, is a common cause. GBS can elaborate a factor that
dampens C5a mediated neutrophil chemotaxis, but neutrophils are still present.
A 17-year-old primigravida has noted no fetal movement during her pregnancy, and she is now
at 18 weeks gestation. Oligohydramnios is noted on fetal ultrasound scan, making it difficult to
visualize fetal internal organs, but the size of the baby appears consistent for 18 weeks
gestational age. Following a counseling session with their physician, the parents decide to
proceed with prostin induction for a medically indicated termination of pregnancy. Autopsy
, reveals no external anomalies upon examination of the stillborn male. Which of the following
findings is most likely to explain this deformation sequence? correct answers Urethral atresia.
The oligohydramnios is part of a deformation sequence resulting in pulmonary hypoplasia. The
urethral atresia precludes output of fetal urine. The atresia should increase the size of the fetal
bladder, but in this case imaging was difficult.
A 32-year-old G2 P1 woman has an uncomplicated vaginal delivery of a 30 week gestational age
male infant. Apgar scores of 5 and 7 at 1 minute and 5 minutes are recorded at the time of birth.
The baby then begins to exhibit increasing respiratory difficulty in the next hour, culminating in
the need for intubation and mechanical ventilation. Which of the following laboratory tests
during gestation is most likely to predict the complication observed in this infant? correct
answers Lamellar body count on amniotic fluid. There is fetal lung immaturity leading to hyaline
membrane disease with neonatal respiratory distress syndrome. Tests for fetal lung maturity
(usually reached by 35 to 36 weeks when there is sufficient production of surfactant by type II
pneumocytes in fetal lung; intracellular surfactant is contained within lamellar bodies), including
the older L:S ratio, as well as lamellar body count, phosphatidylglycerol, and fluorescence
polarization (fpol). These can be done on amniotic fluid.
33-year-old G3 P2 woman gives birth at 38 weeks gestation to a male infant who weighs 2270
gm. Apgar scores are 7 and 9 at 1 and 5 minutes after birth. This neonate has no external
anomalies present on physical examination except that he appears somewhat disproportionate,
with a head size more appropriate for gestational age than body size. The pregnancy was
uncomplicated. Which of the following conditions is most likely to account for these findings?
correct answers Maternal tobacco use. Smoking is the most common cause for low birth weight
babies in developed nations. From maternal causes, the head size tends to be preserved in the
fetus. Such babies have more complications following birth.
A genetic counselor elicits the history that three adult males and one adult female in a family of
10 over 3 generations have an intellectual disability, the males more severely so. Physical
examination of these affected males reveals no major morphologic anomalies, though their testes
appear to be slightly enlarged, without mass lesions present. These males have been healthy,
without a history of major illnesses. Which of the following genetic abnormalities is the most
likely etiology for these findings? correct answers Fragile X syndrome. This is the most common
cause of familial intellectual disability, with karyotype 46 fra(X)Y. It is due to a 'triple repeat'
mutation of a sequence of three nucleotides involving the FMR-1 gene that codes for FMRP that
is found in cell cytoplasm, most prominently in brain and gonads.
A 21-year-old G2P1 woman feels that she is large for dates. She has felt fetal movement for the
past week. She has a screening fetal ultrasound scan performed at 16 weeks gestation that reveals
markedly increased amniotic fluid (polyhydramnios). Which of the following fetal abnormalities
is most likely to cause this finding? correct answers Small intestinal atresia. Anomalies that
interfere with fetal swallowing are most likely to produce an excess of amniotic fluid.
Esophageal and intestinal atresias do this. Amniotic fluid formed in the kidneys is excreted into
the amniotic cavity, then swallowed and resorbed in the gastrointestinal tract.
