Midterm Flashcards
(68 cards)
What is malformation
Intrinsic disturbance in morphogenesis
What is disruption and what is an example
Extrinsic disturbance in morphogenesis causing secondary damage in developmentally normal tissue
Amniotic band
What is deformation and what are maternal and fetal factors
Deformation is extrinsic disturbance in morphogenesis due to compression by abnormal mechanical forces
Maternal factors- first pregnancy, small uterus, leiomyoma (benign smooth muscle tumor of the uterus)
Fetal factors- oligohydramnios and multiple fetuses
What is sequence and give an example with causes and the sequence
Sequence is when one initiating aberration leads to many secondary defects
Oligohydramnios “Potter Syndrome”
Causes- renal agenesis, placental insufficiency due to maternal HTN, and amniotic leak
Sequence- fetal compression, flat face, mispositioned hands and feet, and lung hypoplasia
What is a syndrome
A syndrome is a combination of anomalies usually as a result of a single pathology that affects many tissues
What is: Agenesis Aplasia Atresia Dysplasia
Agenesis- lack organ and its primordium
Aplasia- lack organ due to failure of its developmental analogue
Atresia- lack opening
Dysplasia- loss of cellular uniformity and organization
What are the 2 general causes of anomalies (broad categories)
Genetic causes
Environmental causes
What are the genetic causes of anomalies and give an example of one
Chromosomal abnormalities
Single gene mutations (mutation in hedgehog results in holoprosencephaly)
What are the 3 environmental causes of anomalies
Viruses
Alcohol
Maternal Diabetes
Explain viral causes of anomalies and give two examples
Cytomegalovirus- 2nd trimester results in microcephaly, mental retardation, and deafness
Rubella- before 16 weeks causes congenital rubella sydrome resulting in cataracts, deafness, heart defects, and mental retardation
Explain alcohol with regards to anomalies and explain the major example
Fetal alcohol syndrome is associated with growth retardation, microcephaly, maxillary hypoplasia, and ASD
Explain the affect of maternal diabetes with regards to anomalies
Maternal diabetes causes fetal hyperinsulinemia which causes increased body fat and muscle mass and causes organomegaly
With regards to pathogenesis of anomalies explain:
Early embryonic period
Weeks 3-9
Fetal Period
Early embryonic period (first 3 weeks)- injury either kills the fetus or it can recover
Weeks 3-9- embryo is very sensitive to teratogens
Fetal period (following organogenesis)- fetus is susceptible to growth retardation
What is the definition of premature
Gestational age less than 37 weeks aka preterm
What are the 3 major risk factors of prematurity, explain them
PPROM- preterm premature rupture of placental membrane is associated with smoking, malnutrion, preterm labor, and gestational vaginal bleeding
Intrauterine infections- associated with chorioamnionitis and funisitis; TLR activation deregulates PG resulting in uterine contractions
Twins
What is fetal growth restriction
Small for gestational age (bottom 10%)
What are the 3 general classes of abnormalities that contribute to fetal growth restriction
Fetal, placental, and maternal abnormalties
Explain fetal abnormalities with regards to fetal growth restriction
Fetal abnormalities cause symmetric growth restriction
Causes include chromosomal abnormalities, congenital anomalies, and ToRCH infections
Explain placental abnormalities with regards to fetal growth restriction
There is extensive fetal growth in the third trimester which places heavy demand on utero-placental blood supply to allow adequate placental growth
Disrupt placental blood flow results in asymmetric growth restriction
Explain maternal abnormalities with regards to fetal growth restriction
Maternal abnormalities include preeclampsia, HTN, hypercoagulability, malnutrition, smoking, and drinking all of which disrupt placental blood flow
What are the causes of neonatal respiratory distress syndromes
RDS (hyaline membrane disease), maternal sedation, fetal head injury during delivery, fetal hypoxia, and maternal diabetes
Explain the pathogenesis of RDS with regards to:
- incidence
- mutant genes
- hypoxia
- clinical info
Incidence of RDS is inversely proportional to gestational age
Mutant SFT genes decrease surfactant production which increases alveoli surface tension which increases pressure requires to expand alveoli
Hypoxia causes acidosis which causes vasoconstriction and hypoperfusion which causes tissue damage which allows plasma to enter alveoli where it complexes with fibrin and necrotic cells to form hyaline membranes which impede gas exchange
Hyperinsulinemia decreases surfactant production while corticosteroids increase production
Explain the morphology of RDS
Lungs are solid, airless, and reddish purple
Alveoli are poorly developed
Protein membranes line bronchioles and alveoli
Eosinophilic hyaline membranes
Explain clinical info of RDS with regards to:
- measuring lung maturity
- treatment if unable to delay delivery and outcomes
- associated disorders
Lung maturity is measured by amniotic fluids lecithin:sphinogmyeline ration
If unable to delay delivery treat with replacement surfactant and O2 therapy (associated with retinopathy and bronchopulmonary dysplasia)
RDS is associated with PDA and NEC