Flashcards in Developmental Disorders Deck (31):
-disturbances in otherwise normal morphogenetic processes
-disturbances in otherwise normal morphogenetic processes. These are typically caused by abnormal biomechanic all forces such as uterine constraints.
-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
-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.
What is the critical period?
-a maturation stage in which the organism is especially sensitive to certain environmental stimuli
What are the three groups of causes of congenital anomalies?
How can genetics create a disorder?
-inborn errors of metabolism (rare)
-inherited most commonly as autosomal recessive or X-linked diseases. Some are dominant.
-often affect enzymes and biochemical pathways
What are some examples of diseases from genetic mutations?
What changes can happen in the chromosomes that can result in genetic disorders?
-aneuploidy (80-90% die in utero)
What is euploidy?
-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
What types of infections may causes birth defects?
What kinds of viruses may contribute to birth defects?
-cytomegalic inclusion disease
What other environmental factors may result in birth defects?
-drugs and other chemicals: thalidomide, alcohol, RA,folic acid
What are some additional developmental problems?
-prematurity and growth restrictions
-neonatal respiratory distress syndrome
What is the second most common cause of neonatal mortality?
-prematurity and fetal growth restrictions
What are some major risk factors for prematurity?
-preterm premature rupture of placental membranes
-uterine, cervical, and placental structural abnormalities
What are some of the hazards of prematurity?
-hyaline membrane disease
-long term complications including developmental delay
What are some fetal factors resulting in fetal growth restriction?
What are some placental factors resulting in fetal growth restriction?
-umbilical-placental vascular anomalies
-placental thrombosis and infarction
-placental genetic mosaicism
What are some maternal factors resulting in fetal growth restriction?
-maternal use of drugs, narcotics, alcohol, nicotine
What is respiratory distress syndrome?
-related to the immaturity of the lungs and related to premature birth
-deficiency in pulmonary surfactant
What is the incidence of respiratory distress syndrome?
-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
What is fetal hydrops? Most common cause?
-accumulation of edema fluid in the fetus during intrauterine growth
-most common causes was hemolysis by blood group incompatibility between mother and fetus
What are the causes of fetal hydrops?
What is immune hydrops?
-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
What are the major causes of nonimmune hydrops?
-cardiovascular defects such as congenital cardiac defects and arrhythmias
+Turner syndrome and trisomies 21 and 18 -> due to cardiac aberrations with these anomalies
What is kericterus?
-a bilirubin induced brain dysfunction (highly neurotoxic)
-newborns are especially vulnerable
What is pregnancy induced hypertension?
-persistent elevated bp that develops after 20 weeks of gestation and returns to normal after birth
What are the symptoms of preeclampsia?
-bp is high
What is eclampsia?
-extremely serious condition
-extremely high bp
-grand meal seizures or coma