Might asphyxia cause respiratory inhibition after crying in mature infants

Background:  To clarify the timing of injury in utero causing respiratory inhibition after crying (RIAC), the relationship between asphyxia and RIAC was investigated in infants whose gestational age was ≥36 weeks. Methods:  RIAC and cranial ultrasound abnormalities were examined for retrospectively in infants treated in the neonatal intensive care unit from April 2004 through March 2009. All included infants were gestational age ≥36 weeks and had an Apgar score <4 points at 1 min. The relationship between RIAC and perinatal factors was also examined. Results:  Twenty-six infants were included. Three infants had RIAC, seven infants had poor prognosis, and nine infants had ultrasound abnormalities in the ganglionic eminence (GE). There was a significant relationship between RIAC and ultrasound abnormalities in the GE (P= 0.032). Poor prognosis was significantly associated with low Apgar score at 5 min (P≤ 0.001), disseminated intravascular coagulation (P= 0.047), hypoxic ischemic encephalopathy (P= 0.028), and brain hypothermia therapy (P= 0.028). There was no significant relationship between RIAC and poor prognosis. All infants had ultrasound abnormalities in the GE on the day of birth. Conclusion:  Damage occurring in utero prior to 36 weeks gestation might cause increased echogenicity or cyst formation in the GE, potentially disturbing maturation of the respiratory center with the development of RIAC.