Chapter 10 Part 1 Flashcards
What defines the neonatal period?
First four weeks of life
What defines the infancy period?
First year of life
What age is considered “toddler”?
Age 1 to 4
What are the leading causes of death in the first 12 months?
congenital anomalies, disorders related to short gestation and low birth weight, and SIDS
Definition of disease
deviation from or interruption of normal structure or function of part of an organ or symptom manifested by characteristics symptoms and sign
Definition of disorder
derangement or abnormality of normal function; morbid physical or mental state
Definition of neoplasm
new and abnormal growth
Definition of syndrome
group of symptoms that occur together
Definition of malformation
primary error in morphogenesis in which there is an intrinsically abnormal developmental process
Definition of disruptions
destruction of an organ or body region that was previously normal; arises from EXTRINSIC disturbance in morphogenesis
Definition of deformations
localized or generalized compression of fetus by abnormal biomechanical forces
What are some maternal factors involved in deformations?
first pregnancy, small uterus, malformed uterus, leiomyoma
What are some fetal or placental factors involved in deformations?
oligohydramnios, multiple fetuses, abnormal presentation, club feet
Definition of sequence
Cascade of anomalies triggered by one initiating aberration; ex. Potter sequence
What are some causes of oligohydramnios?
Leakage of amniotic fluid, renal agenesis, uteroplacental insufficiency due to hypertension
What are some effects of fetal compression due to oligoydramnios?
position defects of hands and feet, breech presentation, altered facies, pulmonary hypoplasia, amnion nodosum (nodules)
Definition of malformation syndrome
constellation of congenital anomalies pathologically related that cannot be explained by one single initiating defect
Definition of agenesis
absence of organ and it’s primoridum
Definition of aplasia
absence of organ due to failure of primordial growth
Definition of atresia
absence of opening
Definition of hypoplasia
incomplete development or decreased size of an organ
Definition of dysplasia
abnormal organization of cells
What are the common known etiologies of most congenital annomalies?
genetic, environmental, multifactorial
When during development do most chromosomal disorders arise?
During gametogenesis
What is the most common developmental defect of the forebrain
Holoprosencephaly
What are some examples of maternal disease states or infections that may cause congenital anomalies?
maternal infection - TORCH, HIV
disease - diabetes, PKU, endocrine issues
What are some examples of teratogens?
thalidomide, alcohol, anticonvulsants, warfarin, 13-cis-retinoic acid
What is a classic presentation of a child with fetal alcohol syndrome?
prenatal and postnatal growth retardation, microcephaly, short palpebral fissures, maxillary hypoplasia
What is a classic presentation of a fetus with a GD mother?
macrosomia, carciac anomalies, neural tube defects, CNS malformations
What are some common multifactorial malformations?
cleft lip, cleft palate, neural tube defects
What are the two pathogenic processes contributed to congenital anomalies?
Time of prenatal teratogenic insult and interplay between teratogens and intrinsic genetic defects
Two phases of intrauterine development
Embryonic period - first 9 weeks
Fetal period - 10 wks to birth
When is the embryo most susceptible to teratogenesis?
between wks 3-9, esp wks 4 and 5; organ development is occurring
What is the fetus most susceptible to in the fetal period?
growth retardation or injury to preformed organs
What is the effect of cyclopamine?
plant teratogen that causes holoprosencephaly and cyclopia, acts on hedgehog signaling pathway
What is the genetic effect of valproic acid?
acts on HOX genes, responsible for limb formation as well as vertebrae and craniofacial structures
What are the genetic effects of EXCESS retinoic acid?
CNS, cardiac, craniofacial defects, cleft lip, cleft palate; TGFB3 pathway dysregulation
What defines a preterm infant?
gestational age < 37 weeks
What defines an extremely preterm infant?
GA <28 weeks
What defines a very preterm infant?
GA 28 to 32 weeks
What defines a moderate to late preterm infant?
GA 32 to 37 weeks
What are the main risk factors for prematurity?
PPROM, intrauterine infection, uterine/cervical/placental abnormalities, multiple gestation
What are the main hazards of prematurity?
neonatal resp distress syndrome, necrotizing enterocolitis, sepsis, intraventricular and germinal matrix hemorrhage
What are some risk factors for PRROM?
history of preterm delivery, preterm labor and/or vaginal bleeding during pregnancy, maternal smoking, low socioeconomic status
What are the most common microorganisms seen in intrauterine infections?
Ureaplasma urealyticum, Mycoplasma hominis, Gardnerella vaginalis, trichomonas, gonorrhea, chlamydia
What role do TLRs play in intrauterine infection?
Bind bacteria and deregulate prostaglandin expression, triggering smooth muscle contractions in uterus
What is the etiology of fetal growth restriction?
can be placental, maternal, or fetal anomalies
What is the pathogenesis of fetal growth restriction?
infection, chromosomal, preeclampsia
What is the outcome for SGA infants?
depending on cause and degree, there is a SIGNIFICANT risk of morbidity in forms of handicap, cerebral dysfx, learning disability, or hearing and visual impairment
What are the most common fetal abnormalities and how do these SGA infants grow?
chromosomal, infection, anomalies; causes symmetric growth restriction (proportionate FGR), all systems similarly effected
What are some causes of utero-placental insufficiency?
placental abruption, vascular anomalies, placenta previa, placental thrombosis, placental infections, multiple gestations
What kind of growth pattern occurs in SGA infants with utero-placental insufficiency?
asymmetric growth retardation with sparing of the brain
Etiology of RD in new born
RDS, excessive maternal sedation, fetal head injury, aspiration of blood or amniotic fluid, and intrauterine hypoxia
Pathogenesis of RDS
immaturity of lungs, deficiency of pulmonary surfactant
What is surfactant made up of?
lecithin, phosphatidylglycerol, surfactant proteins for host defense and decrease in surface tension
What is the main outcome of endothelial and epithelial damage in RDS?
fibrin and necrotic cells forming a hyaline membrane in the lungs
What things stimulate surfactant production?
cortisol, insulin, prolactin, thyroxine, TGFB
What are some things that can increase the likelihood of RDS?
GD and c-section
What are some of the key morphological characteristics of RDS?
alternating atelectasis and dilation of alveoli, necrotic cellular debris incorporated within eosinophilic hyaline membranes lining bronchioles, alveolar ducts, and alveoli
What is the common presentation of RDS
intercostal and substernal retractions, perioral cyanosis, preterm but appropriate weight, rales, ground glass opacification on xray
What mutated genes are associated with congenital surfactant deficiency?
SFTPB and SFTPC
What is tested in amniotic fluid to assess lung maturity?
lecithin-sphingomyelin ratio, >2.0 indicates lung maturity
What are the two most common complications associated with prolonged oxygen supply for RDS infants?
retrolental fibroplasia and bronchopulmonary dysplasia
Pathogenesis of retinopathy of prematurity
- Hyperoxic phase: decreased VEGF causing apoptosis
2. Hypoxic phase (on room air): increased VEGF inducing retinal vessel proliferation
Pathogenesis of bronchopulmonary dysplasia
decrease in alveolar septation and dysmorphic capillary configuration, proinflammatory cytokines disrupt alveolar development
What key inflammatory cytokines are involved in bronchopulmonary dysplasia?
TNF, IL-1B, IL-6, IL-8
Pathogenesis of necrotizing entercolitis
multifactorial; prematurity, enteral feeding with postnatal insult
What is the role of PAF in necrotizing enterocolitis?
increasing mucosal permeability by promoting enterocyte apoptosis and compromising tight junctions
Clinical course of necrotizing enterocolitis
bloody stools, abd distention, circulatory collapse, gas within intestinal wall on xray
What organs does NEC typically involve?
terminal ileum, cecum, right colon; BUT any part of intestines may be involved
Gross morphological changes to intestines in NEC
distended, friable, congested, gangrenous, perforation accompanying peritonitis
Microscopic morphological changes to intestines in NEC
mucosal or transmural coagulative necrosis, ulceration, bacterial colonization, submucosal gas bubbles (pneumatosis intestinalis)
What are some possible complications associated with surgical treatment for NEC?
strictures from fibrosis, decreased absorption
