Developmental Disorders

Question 1

Define disruptions.

Answer 1

-disturbances in otherwise normal morphogenetic processes

Question 2

Define deformations.

Answer 2

-disturbances in otherwise normal morphogenetic processes. These are typically caused by abnormal biomechanic all forces such as uterine constraints.

Question 3

Define sequences.

Answer 3

• a sequence is a series of events triggered by one initiating factor.
• example: oligohydramnios which leads to a variety of events including fetal compression and other problems

Question 4

Define syndrome.

Answer 4

-constellations of congenital anomalies that are thought to be pathologically related but cannot be explained on the basis of a single local event. They are often caused by a single event such as a viral infection.

Question 5

What is the critical period?

Answer 5

-a maturation stage in which the organism is especially sensitive to certain environmental stimuli

Question 6

What are the three groups of causes of congenital anomalies?

Answer 6

• genetic (18%)
• environmental (7%)
• multifactorial (25%)

Question 7

How can genetics create a disorder?

Answer 7

• inborn errors of metabolism (rare)
• inherited most commonly as autosomal recessive or X-linked diseases. Some are dominant.
• often affect enzymes and biochemical pathways

Question 8

What are some examples of diseases from genetic mutations?

Answer 8

• phenylketonuria
• galactosemia
• cystic fibrosis

Question 9

What changes can happen in the chromosomes that can result in genetic disorders?

Answer 9

• aneuploidy (80-90% die in utero)
• deletions
• duplications
• inversion
• trans locations

Question 10

What is euploidy?

Answer 10

• involves the addition of a complete set of chromosomes in addition to the diploid stage
• often the result of a retention of a polar body or by fertilization by more than one sperm
• typically results in early spontaneous abortion

Question 11

What types of infections may causes birth defects?

Answer 11

• viruses
• bacterial
• protozoan

Question 12

What kinds of viruses may contribute to birth defects?

Answer 12

• rubella
• cytomegalic inclusion disease
• herpes simplex
• varicella-zoster
• influenza
• mumps

Question 13

What other environmental factors may result in birth defects?

Answer 13

• drugs and other chemicals: thalidomide, alcohol, RA,folic acid
• radiation
• maternal diabetes

Question 14

What are some additional developmental problems?

Answer 14

• prematurity and growth restrictions
• neonatal respiratory distress syndrome
• hydrops
• eclampsia

Question 15

What is the second most common cause of neonatal mortality?

Answer 15

-prematurity and fetal growth restrictions

Question 16

What are some major risk factors for prematurity?

Answer 16

• preterm premature rupture of placental membranes
• intrauterine infections
• uterine, cervical, and placental structural abnormalities
• multiple gestation

Question 17

What are some of the hazards of prematurity?

Answer 17

• hyaline membrane disease
• necrotizing entercolitis
• sepsis
• interventricular hemorrhage
• long term complications including developmental delay

Question 18

What are some fetal factors resulting in fetal growth restriction?

Answer 18

• chromosome disorders
• congenital anomalies
• congenital infections

Question 19

What are some placental factors resulting in fetal growth restriction?

Answer 19

• umbilical-placental vascular anomalies
• placenta previa
• placental thrombosis and infarction
• multiple gestations
• placental genetic mosaicism

Question 20

What are some maternal factors resulting in fetal growth restriction?

Answer 20

• preeclampsia
• chronic hypertension
• maternal use of drugs, narcotics, alcohol, nicotine
• maternal malnutrition

Question 21

What is respiratory distress syndrome?

Answer 21

• related to the immaturity of the lungs and related to premature birth
• deficiency in pulmonary surfactant

Question 22

What is the incidence of respiratory distress syndrome?

Answer 22

-incidence is inversely proportional to gestational age

• 60% of infants born at less than 28 weeks
• 30% of infants born between 28-34 weeks
• 5% or less of infants after 34 weeks

Question 23

What is fetal hydrops? Most common cause?

Answer 23

• accumulation of edema fluid in the fetus during intrauterine growth
• most common causes was hemolysis by blood group incompatibility between mother and fetus

Question 24

What are the causes of fetal hydrops?

Answer 24

• immune hydrops

- nonimmune hydrops

Question 25

What is immune hydrops?

Answer 25

• caused by blood group incompatibility between mother and fetus
• fetal red cells reach the maternal blood stream during last trimester or during childbirth itself
• major factor is the D antigen of Rh group
• ABO incompatibility is generally not a problem because maternal Ab remove any incompatible fetal RBCs that cross the placenta

Question 26

What are the major causes of nonimmune hydrops?

Answer 26

-cardiovascular defects such as congenital cardiac defects and arrhythmias

-chromosomal anomalies
+Turner syndrome and trisomies 21 and 18 -> due to cardiac aberrations with these anomalies

Question 27

What is kericterus?

Answer 27

• a bilirubin induced brain dysfunction (highly neurotoxic)

- newborns are especially vulnerable

Question 28

What is pregnancy induced hypertension?

Answer 28

-persistent elevated bp that develops after 20 weeks of gestation and returns to normal after birth

Question 29

What are the symptoms of preeclampsia?

Answer 29

• bp is high
• proteinuria
• weight gain
• edema

Question 30

What is eclampsia?

Answer 30

• extremely serious condition
• extremely high bp
• grand meal seizures or coma

Question 31

Define malformation.

Answer 31

-primary errors of mophogenesis. They are usually multifactorial, involving a number of etiological agents including genetic and environmental