Ch 10 Prematurity and Fetal Growth Flashcards
prematurity
gestational age less than 37 weeks, is the second most common cause of neonatal mortality
major risk factors for prematurity
PPROM
intrauterine infection
uterine, cervical, placental structural abnormalities
multiple gestation
RDS most common cause
hyaline membrane disease b/c of the deposition of a layer of hyaline proteinaceous material in the peripheral airspaces of infants who succumb to this condition
RDS - characteristic findings
preterm, male, maternal diabetes, cesarean section
fine rales
chest x ray - uniform minute reticulogranular densities (ground glass picture)
resuscitation at birth
breathing becomes more difficult - cyanosis
RDS - pathogenesis
fundamental defect is deficiency of pulmonary surfactant
SFTPB and SFTBC - genes (congenital)
type II alveolar cells make surfactant after 35th week
production is controlled by hormones and GF, cortisol, insulin, prolactin, thyroxine, TGF beta
RDS - morphology
necrotic cellular debris in terminal bronchioles and alveolar ducts
eosinophilic hyaline membranes
RDS - clinical features
retrolental fibroplasia
bronchopulmoary dysplasia
retrolental fibroplasia
retinopathy of prematurity in the eyes
hypertoxic phase - decrease in VEGF leads to endothelial cell apoptosis
neovascularization - VEGF levels rebound leading to retinal vessel proliferation and lesions in the retina
bronchopulmonary dysplasia
major abnormality is decrease in alveolar separation and dysmorphic capillary configuration
reversible impairment in development of alveolar sepation
necrotizing enterocolitis
enteral feeding - postnatal insult sets in motion the cascade leading to tissue destruction
PAF - increasing mucosal permeability by promoting apoptosis
NE - clinical course
onset of bloody stools, abdominal distension and development of circulatory collapse pneumatosis intestinalis (gas w/in the intestinal wall)
NE - morphology
involved segment is distended, friable, congested, or gangrenous
