Preterm labor and birth

Epidemiology

Maternal and fetal conditions
- Infections (e.g., urinary tract infections, STIs, vaginal infections )
- Hypertensive pregnancy disorders (e.g., preeclampsia, HELLP syndrome)
- Diabetes mellitus, gestational diabetes
Lifestyle and environmental factors
- Smoking
- Substance use (e.g., heavy alcohol use, heroin, cocaine)
- Maternal or fetal stress
- Maternal age (≤ 18 years, > 35 years)

Definition: Bleeding into the ventricles from the germinal matrix, a highly vascularized region within the subventricular zone of the brain from which cells migrate out during brain development.
Etiology: associated with a number of risk factors
- Birth weight < 1500 g and delivery before 32 weeks' gestation due to the fragility of the germinal matrix and/or impaired autoregulation of blood pressure
- Maternal chorioamnionitis
Pathophysiology
- Immaturity of the basal lamina and lack of astrocytic glial fibrillary acidic protein within the germinal matrix leads to abnormal cerebral autoregulation.
- Alterations in an infant's blood pressure (e.g., during birth, intubation) → failure of cerebral autoregulation to compensate for the change in blood pressure → rupture of and bleeding from vessels in the germinal matrix → rupture of ependyma → blood flows into the ventricles
Clinical features
- Usually occurs within the first days of life (up to day 5)
- Most infants are asymptomatic, but saltatory (for several days) or, more rarely, catastrophic (over minutes to hours) courses are also possible.
- Lethargy, hypotonia, irregular respirations, seizures, bulging anterior fontanelle
- Cranial nerve abnormalities (e.g., pupils react sluggishly to light) and changes in eye movement (e.g., roving eye movements)