Etiology

• Fetal cardiovascular abnormalities (e.g., congenital heart defects)

• Fetal pulmonary abnormalities (e.g., decreased surfactant related to prematurity, aspiration of amniotic fluid, meconium aspiration syndrome, persistent pulmonary hypertension of the newborn)

(play the biggest role)

• Placental abnormalities (e.g., fetal vascular malperfusion, thrombosis)

• Congenital infections

• Substance use (e.g., alcohol, cocaine, amphetamines)

• Abnormal maternal oxygenation (e.g., due to trauma, hypotension, severe anemia)

• Maternal conditions (e.g., diabetes mellitus, preeclampsia, congestive heart failure)

• Traumatic delivery (e.g., shoulder dystocia, emergency cesarean delivery, failed vacuum-assisted delivery)

• Cesarean delivery with general anesthesia

• Impaired placental perfusion (e.g., placental abruption, abnormal uterine contractions, uterine rupture)

• Abnormal maternal oxygenation (e.g., pulmonary edema in preeclampsia)

• Maternal hemodynamic compromise (e.g., amniotic fluid embolus)

• Umbilical cord prolapse, nuchal cord, umbilical cord knot