**Background:** Since 1992, the American Academy of Pediatrics (AAP) has recommended supine sleep on a flat surface to prevent SIDS, yet inclined sleep devices (10°–30°) and car safety seats (30°–45°) remain commonly used. Some caregivers and healthcare providers use inclined positioning to manage gastroesophageal reflux disease (GERD) symptoms in infants, despite AAP recommendations against this practice. The 2016 SIDS guidelines cited only one study with 24 infants regarding inclined position and GERD, and the 2022 guidelines cited a second study with 79 participants. This exploratory study aimed to evaluate whether inclined positioning reduces hypoxia, bradycardia, and clinical signs of post-feed regurgitation in infants with GERD compared with flat supine positioning.
**Methods:** A convenience sample of 25 infants with GERD and 10 healthy controls aged 1 to <5 months were enrolled from a single practice (Penn State Health, Hershey, PA) from March 2021 to January 2022. Inclusion criteria included gestational age ≥34 weeks, weight ≥10th percentile, and head circumference between 3rd and 97th percentile. Infants with GERD required a healthcare provider diagnosis plus ≥4 visible daily spit-ups for ≥5 days in the prior week, or ≥2 daily spit-ups out of the nose for ≥5 days, or a score ≥16 on the Infant Gastroesophageal Reflux Questionnaire Revised. Parents agreed to withhold GERD medication for 12 hours before participation. At the study visit, infants were fed a typical liquid meal (breastmilk or formula). Between 15–20 minutes after feeding, infants were placed in a prototype reclining device at four incline positions (0°, 10°, 18°, and 28°) for 15 minutes each in randomized order, with a 1–5 minute washout between positions. Continuous pulse oximetry (Masimo RAD-97) measured oxygen saturation and heart rate at 2-second intervals. Hypoxia was defined as O2 saturation <94% and bradycardia as heart rate <100. A study coordinator recorded regurgitation episodes, crying/fussing, hiccups, back arching, and breathing difficulty. Mothers rated infant comfort on a 1–5 ordinal scale. Statistical analyses used mixed effects negative binomial regression (hypoxia, bradycardia), Poisson regression (regurgitation), mixed effects logistic regression (crying), and mixed effects linear regression (comfort), all with fixed effects for incline and random intercept for infant.
**Key Results:** Among infants with GERD, 17 (68%) experienced ≥1 hypoxia episode across all positions (80 total episodes, median 20 seconds duration), 13 (54%) had ≥1 bradycardia episode (33 total episodes, median 22 seconds), and 15 (60%) had ≥1 regurgitation episode (28 total episodes). However, in each individual position, most infants had no episodes of hypoxia, bradycardia, or regurgitation. For hypoxia, incidence rate ratios (IRRs) compared with 0° were 0.56 (95% CI: 0.21–1.47) at 10°, 0.72 (95% CI: 0.28–1.82) at 18°, and 0.59 (95% CI: 0.22–1.49) at 28°. For bradycardia, IRRs were 0.35 (95% CI: 0.04–2.17) at 10°, 3.99 (95% CI: 0.91–17.0) at 18°, and 0.33 (95% CI: 0.04–2.07) at 28°. For regurgitation, IRRs were 1.03 (95% CI: 0.32–3.30) at 10°, 2.06 (95% CI: 0.80–5.93) at 18°, and 0.67 (95% CI: 0.17–2.33) at 28°. All confidence intervals were wide and crossed 1.0, indicating no statistically significant differences. Crying/fussing odds ratios ranged from 0.69 (95% CI: 0.16–2.89) at 10° to 3.12 (95% CI: 0.79–14.2) at 18°. Maternal comfort ratings showed mean differences from −0.20 to 0.07, all with confidence intervals crossing zero. Time since feeding was not associated with hypoxia or bradycardia but was associated with regurgitation (IRR = 1.59 per 15 minutes closer to feeding, 95% CI: 1.14–2.22). Notably, 60% of parents of infants with GERD reported using car safety seats for sleep during the night, and 32% reported using inclined sleep.
**Clinical Implications:** This pilot study found that brief episodes of hypoxia and bradycardia, as well as visible regurgitation, are common in infants with GERD after feeding regardless of incline angle, with no statistically significant differences between flat supine (0°) and inclined positions (10°, 18°, 28°). While point estimates suggested possible reductions in hypoxia and bradycardia at some incline angles, the wide confidence intervals preclude definitive conclusions. The high prevalence of car safety seat use for nighttime sleep (>50%) is concerning from a SIDS prevention standpoint. The authors acknowledge significant limitations including small sample size, lack of objective GERD measures (e.g., pH-MII probe), short observation period (1 hour), unquantified feeding volumes, and lack of demographic diversity. These data may be used to power future, larger, and longer evaluations to inform guidelines regarding sleep safety and car safety seat use for infants with GERD.