Asymmetric intrauterine growth restriction is a risk factor for respiratory inhibition after crying in infants.

Objective: We investigated whether intrauterine growth restriction (IUGR) correlated with respiratory inhibition after crying (RIAC) and feeding hypoxemia.

Methods: We screened for RIAC among 1248 infants with a gestational age ≥36 weeks using our established method with cranial ultrasound, SpO2 monitoring, and polygraphy. We classified the infants into three groups: symmetric IUGR, asymmetric IUGR, and control. We compared the perinatal factors with the incidence of RIAC and feeding hypoxemia among the three groups.

Results: Overall, 26 infants had symmetric IUGR, 143 infants had asymmetric IUGR, and 1079 infants were in the control group. RIAC was observed in 10 (6.9%) infants in the asymmetric IUGR group and in 37 (3.4%) infants in the control group. Feeding hypoxemia was observed in 15 (10.5%) infants in the asymmetric IUGR group and in 52 (4.8%) infants in the control group. The incidence of RIAC and feeding hypoxemia in the asymmetric IUGR group was significantly more than that in the control group. None of the infants with symmetric IUGR exhibited RIAC or feeding hypoxemia.

Conclusions: The results indicate that asymmetric IUGR is a risk factor for RIAC and feeding hypoxemia. These infants should be aggressively screened for RIAC.