Acid gastroesophageal reflux in convalescent preterm infants: effect of posture and relationship to apnea

Concerns regarding gastroesophageal reflux (GER) and associated apnea episodes result in some practitioners having convalescent, prematurely born infants sleep in the prone position. We have tested the hypothesis that such infants would not suffer from clinically important acid GER or associated apnea episodes more in the supine compared with the prone position. Lower esophageal pH was measured and videopolysomnographic recordings of nasal airflow, chest and abdominal wall movements, electrocardiographic activity, and oxygen saturation were made on two successive days of 21 premature infants (median gestational age 28 wk) at a median postmenstrual age (PMA) of 36 wk. On each day, the infants were studied prone and supine. The acid reflux index was higher in the supine compared with the prone position (median 3% versus 0%, p = 0.002), but was low in both positions. The number of obstructive apnea episodes per hour was higher in the supine position (p = 0.008). There were, however, no statistically significant correlations between the amount of acid GER and the number of either obstructive or total apnea episodes in either the supine or prone position. Supine compared with prone sleeping neither increases clinically important acid GER nor obstructive apnea episodes associated with acid GER in asymptomatic, convalescent, prematurely born infants.