Review question: in preterm infants whose mothers want to breastfeed, does using bottles interfere with breastfeeding success?
Background: preterm infants start milk feeds by tube, and as they mature they are able to manage sucking feeds. The number of sucking feeds each day is gradually increased as the baby matures. Women with preterm infants may not always be in hospital every time the baby needs a sucking feed. Conventionally, bottles with mother's milk or formula have been used. It has been suggested that using bottles may interfere with breastfeeding success.
Study characteristics: we found seven eligible studies (involving 1152 preterm babies). These studies were of small to moderate size, and most had some problems with study design or conduct. The search is up to date as of 18 June 2020.
Key results: five studies (which included two of the largest studies) used cup feeds, and one used tube feeds. One study used a specially designed teat with feeding action suggested to be more like breastfeeding than conventional bottle feeding. Most studies were conducted in high-income countries, only two in middle-income countries and none in low-income countries. Overall if bottle feeds (with a conventional teat) were not given, babies were more likely to be fully breastfed or to have at least some breastfeeds on discharge home and at three and six months postdischarge home. The study with the specially designed teat showed no difference in breastfeeding outcomes, so it was the cup alone or the tube alone that improved breastfeeding rates. However, because of the poor quality of the tube alone study, we are uncertain whether a tube alone approach to supplementing breastfeeds improves breastfeeding outcomes. We found no evidence of benefit or harm for any of the reported outcomes, including length of hospital stay or weight gain.
Conclusions: using a cup instead of a bottle increases the extent and duration of full and any breastfeeding in preterm infants up to six months postdischarge. Further high-quality studies of the tube alone approach should be undertaken.
Certainty of evidence: we have low to moderate confidence in these results.
Avoiding the use of bottles when preterm infants need supplementary feeds probably increases the extent of any breastfeeding at discharge, and may improve any and full breastfeeding (exclusive) up to six months postdischarge. Most of the evidence demonstrating benefit was for cup feeding. Only one study used a tube feeding strategy. We are uncertain whether a tube alone approach to supplementing breastfeeds improves breastfeeding outcomes; further studies of high certainty are needed to determine this.
Preterm infants often start milk feeds by gavage tube. As they mature, sucking feeds are gradually introduced. Women with preterm infants may not always be in hospital to breastfeed their baby and need an alternative approach to feeding. Most commonly, milk (expressed breast milk or formula) is given by bottle. Whether using bottles during establishment of breastfeeds is detrimental to breastfeeding success is a topic of ongoing debate.
To identify the effects of avoidance of bottle feeds during establishment of breastfeeding on the likelihood of successful breastfeeding, and to assess the safety of alternatives to bottle feeds.
A new search strategy was developed for this update. Searches were conducted without date or language limits in September 2021 in: MEDLINE, CENTRAL, and CINAHL. We also searched the ISRCTN trial registry and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-RCTs.
We included RCTs and quasi-RCTs comparing avoidance of bottles with use of bottles for preterm infants where their mothers planned to breastfeed.
Two review authors independently assessed trial quality and extracted data. When appropriate, we contacted study authors for additional information. We used the GRADE approach to assess the certainty of evidence. Outcomes included full breastfeeding and any breastfeeding on discharge home and at three and six months after discharge, as well as length of hospital stay and episodes of infant infection. We synthesised data using risk ratios (RR), risk differences (RD) and mean differences (MD), with 95% confidence intervals (CI). We used the GRADE approach to assess the certainty of the evidence.
We included seven trials with 1152 preterm infants in this updated review. There are three studies awaiting classification. Five included studies used a cup feeding strategy, one used a tube feeding strategy and one used a novel teat when supplements to breastfeeds were needed. We included the novel teat study in this review as the teat was designed to closely mimic the sucking action of breastfeeding. The trials were of small to moderate size, and two had high risk of attrition bias. Adherence with cup feeding was poor in one of the studies, indicating dissatisfaction with this method by staff or parents (or both); the remaining four cup feeding studies provided no such reports of dissatisfaction or low adherence.
Avoiding bottles may increase the extent of full breastfeeding on discharge home (RR 1.47, 95% CI 1.19 to 1.80; 6 studies, 1074 infants; low-certainty evidence), and probably increases any breastfeeding (full and partial combined) on discharge (RR 1.11, 95% CI 1.06 to 1.16; studies, 1138 infants; moderate-certainty evidence). Avoiding bottles probably increases the occurrence of full breastfeeding three months after discharge (RR 1.56, 95% CI 1.37 to 1.78; 4 studies, 986 infants; moderate-certainty evidence), and may also increase full breastfeeding six months after discharge (RR 1.64, 95% CI 1.14 to 2.36; 3 studies, 887 infants; low-certainty evidence).
Avoiding bottles may increase the occurrence of any breastfeeding (full and partial combined) three months after discharge (RR 1.31, 95% CI 1.01 to 1.71; 5 studies, 1063 infants; low-certainty evidence), and six months after discharge (RR 1.25, 95% CI 1.10 to 1.41; 3 studies, 886 infants; low-certainty evidence). The effects on breastfeeding outcomes were evident at all time points for the tube alone strategy and for all except any breastfeeding three months after discharge for cup feeding, but were not present for the novel teat. There were no other benefits or harms including for length of hospital stay (MD 2.25 days, 95% CI −3.36 to 7.86; 4 studies, 1004 infants; low-certainty evidence) or episodes of infection per infant (RR 0.70, 95% CI 0.35 to 1.42; 3 studies, 500 infants; low-certainty evidence).