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Flashcards in Developmental Disorders Deck (31):

Define disruptions.

-disturbances in otherwise normal morphogenetic processes


Define deformations.

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


Define sequences.

-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


Define syndrome.

-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?

-genetic (18%)

-environmental (7%)

-multifactorial (25%)


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?



-cystic fibrosis


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

-aneuploidy (80-90% die in utero)




-trans locations


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
-herpes simplex


What other environmental factors may result in birth defects?

-drugs and other chemicals: thalidomide, alcohol, RA,folic acid


-maternal diabetes


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

-intrauterine infections

-uterine, cervical, and placental structural abnormalities

-multiple gestation


What are some of the hazards of prematurity?

-hyaline membrane disease

-necrotizing entercolitis


-interventricular hemorrhage

-long term complications including developmental delay


What are some fetal factors resulting in fetal growth restriction?

-chromosome disorders

-congenital anomalies

-congenital infections


What are some placental factors resulting in fetal growth restriction?

-umbilical-placental vascular anomalies

-placenta previa

-placental thrombosis and infarction

-multiple gestations

-placental genetic mosaicism


What are some maternal factors resulting in fetal growth restriction?


-chronic hypertension

-maternal use of drugs, narcotics, alcohol, nicotine

-maternal malnutrition


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?

-immune hydrops

-nonimmune 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

-chromosomal anomalies
+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


-weight gain



What is eclampsia?

-extremely serious condition

-extremely high bp

-grand meal seizures or coma


Define malformation.

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