Bottom-vented bottles may not reduce gastrointestinal discomfort in infants

1. In this randomized controlled trial, bottom‑vented bottles did not reduce mild gastrointestinal discomfort overall in infants aged 0–90 days.

Evidence Rating Level: 1 (Excellent) 

Bottle feeding infants in the first 6 months has become more common, with over 60% reported, which may be due to low lactation, infection, or a busy work schedule. Bottle feeding can affect how a baby eats, which can impact a variety of health and growth factors. A vent must be designed into the bottle to ensure smooth milk flow and generally falls under 1 of 2 categories: teat-vented and bottom-vented, with air holes on the teat and bottom sides, respectively. Bottom-vented bottles theoretically have benefits for the infants; avoiding milk oxidation and lower air intake, which can cause colic and gas in the infant. This randomized control trial aimed to determine if mild gastrointestinal discomfort (MGD) was reduced in infants using bottom-vented compared to teat-vented bottles. A total of 1041 (mean [SD] age, 25.4 [24.9] days, 575 males [55.2%], 107 [10.3%] premature) infants were included in the final study, among which 36.6% had prior MGD. At week 2, the difference in MGD prevalence was slight but not significant (185 infants [35.5%] vs 197 infants [37.9%]; RR, 0.94; 95% CI, 0.80-1.10; P = .44), not varying with premature status (full-term birth, RR, 0.89; 95% CI, 0.75-1.06; preterm birth, RR, 1.39; 95% CI, 0.89-2.19; P = .07 for interaction), or feeding frequency (<6 times, RR, 1.08; 95% CI, 0.87-1.34; ≥6 times, RR, 0.77; 95% CI, 0.61 to 0.98; P = .06 for interaction). However, infants aged over 60 days showed 55% lower (15 infants [21.1%] vs 24 infants [47.1%]; RR, 0.45; 95% CI, 0.26-0.77) MGD prevalence. While previous studies had noticed a link between bottom venting and MGD, this larger study did not. This may be owed to very few high-frequency feedings of over 6 times a day, giving fewer effects overall, and younger and premature infants not generating the necessary suction pressure. While MGD was not seen, crying was much less prevalent among bottom-vented bottles, showing potential for greater comfort while feeding. These findings suggest that while bottom‑vented bottles do not broadly reduce gastrointestinal discomfort in young infants, their potential benefits in older infants and in reducing feeding‑related crying merit further investigation.

Click here to read the study in JAMA Network Open

Image: PD

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