One new trial (Pickler 2004) was identified and included as a result of the most recent search.
Non-nutritive sucking is used during gavage feeding and in the transition from gavage to breast/bottle feeding in preterm infants. The rationale for this intervention is that non-nutritive sucking facilitates the development of sucking behaviour and improves digestion of enteral feedings. Non-nutritive sucking has been considered to be a benign intervention, although it has the potential to have a negative effect on breastfeeding or on the incidence of later oral aversion.
To determine whether non-nutritive sucking (NNS) in preterm infants influences: a) weight gain, b) energy intake, c) heart rate, d) oxygen saturation, e) length of hospital stay, f) intestinal transit time, g) age at full oral feeds, or h) any other clinically relevant outcomes.
MEDLINE and CINAHL databases back to 1976 and The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2005) were searched. The EMBASE database was added to the search strategy for 2005. Reference lists/bibliographies of relevant articles and reviews were also searched. A comprehensive list of relevant articles was sent to two major authors in this area. They were asked if they knew of any other published or unpublished studies relevant to the area that had not been included in the original list.
All trials utilizing experimental or quasi-experimental designs in which non-nutritive sucking in preterm infants was compared to no provision of non-nutritive sucking. Measured clinically relevant outcomes. Reports were in English or a language for which a translator was available.
Computerized searches were conducted by both reviewers. All potentially relevant titles and abstracts identified by either reviewer were extracted. All retrieved articles were assessed for relevance independently by each reviewer, based on a pre-determined set of criteria. The reference lists/bibliographies of each article were reviewed independently for additional relevant titles and were also retrieved and assessed for relevance. Articles that met all relevance criteria were then assessed for methodologic quality based on a predetermined set of criteria. Those articles judged to have the appropriate quality by both reviewers were included in the analysis.
Data were extracted independently by the two authors. No subgroup analyses were performed because of the small number of studies related to the relevant outcomes.
This review consisted of 21 studies, 15 of which were randomized controlled trials. NNS was found to decrease significantly the length of hospital stay in preterm infants. The review did not reveal a consistent benefit of NNS with respect to other major clinical variables (weight gain, energy intake, heart rate, oxygen saturation, intestinal transit time, age at full oral feeds and behavioral state). The review identified other positive clinical outcomes of NNS: transition from tube to bottle feeds and better bottle feeding performance. No negative outcomes were reported in any of the studies.
This review found a significant decrease in length of stay in preterm infants receiving a NNS intervention. The review did not reveal a consistent benefit of NNS with respect to other major clinical variables (weight gain, energy intake, heart rate, oxygen saturation, intestinal transit time, age at full oral feeds and behavioral state).
The review identified other positive clinical outcomes of NNS: transition from tube to bottle feeds and better bottle feeding performance. No negative outcomes were reported in any of the studies. There were also a number of limitations of the presently available evidence related to the design of the studies, outcome variability, and lack of long-term data. Based on the available evidence, NNS in preterm infants would appear to have some clinical benefit. It does not appear to have any short-term negative effects.
In view of the fact that there are no long-term data, further investigations are recommended. In order to facilitate meta-analysis of these data, future research in this area should involve outcome measures consistent with those used in previous studies. In addition, published reports should include all relevant data.
The early components of sucking have been demonstrated to occur in fetal life from about seven to eight weeks post-conceptual age. Oral and gag reflexes appear at about 12-16 weeks and sucking at 24 weeks. Sucking and swallowing are present by 28 weeks, although not fully coordinated until about 32-34 weeks (Goldson 1987).
The development of sucking behaviours in preterm infants is thought to reflect neurobehavioural maturation and organization. From a clinical perspective, the ability to feed depends upon a coordinated sucking, swallowing and breathing pattern. In preterm infants less than 32 weeks gestation, this ability is not usually effective enough to sustain full oral feeds. In the interim, infants are fed by gavage tube until they are mature enough to take milk directly from the breast or bottle. Non-nutritive sucking has been used during gavage feeding and in the transition from gavage to breast/bottle feeding. The rationale for this intervention is that non-nutritive sucking facilitates the development of sucking behaviour and improves digestion of enteral feeds. A number of enzymes/hormones have been implicated in the facilitation of digestion through non-nutritive sucking; lingual lipase, gastrin, insulin and motilin. Non-nutritive sucking is thought to stimulate the secretion of these enzymes/hormones through vagal innervation in the oral mucosa (Hamosh 1979; Chey 1980; Wiener 1987) In addition, non-nutritive sucking is believed to have a calming effect on infants and is commonly used as an intervention in nurseries and neonatal intensive care units (Kimble, 1992). Non-nutritive sucking has been considered to be a benign intervention, although it has the potential to have a negative effect on breastfeeding or on the incidence of later oral aversion.
Non-nutritive sucking is organized in a stable temporal pattern whose features can be analyzed by quantitative techniques (Wolff 1972). Non-nutritive sucking has been studied using quasi-experimental and experimental designs for its effect on neonates with respect to a number of clinical outcomes.
Schwartz 1987 synthesized five studies of non-nutritive sucking in preterm infants in a meta-analysis. The authors concluded that non-nutritive sucking reduced the time to first bottle feeding and reduced the days of hospitalization. Outcome data related to weight gain were inconclusive.
A meta-analysis of the non-nutritive sucking research in preterm infants by Steer, Lucas and Sinclair (Steer 1992) included eight randomized trials. The major outcome variables studied in these trials included weight gain, gastrointestinal transit, readiness for nipple feedings and length of hospitalization. A lack of blinding to the intervention and/or outcome measurement in all studies affected the methodologic quality of the findings. The authors concluded that in view of the limitations in the available research, there was insufficient beneficial evidence to support the use of non-nutritive sucking in the management of tube-fed preterm infants.
The review of literature demonstrates the need for the continued synthesis of available evidence to support the on-going use of non-nutritive sucking interventions in neonatal care.
This review updates the existing review of non-nutritive sucking in premature infants which was published in The Cochrane Library, Issue 3, 2003. Oxford:Update software.
The objectives of this review are to examine the evidence for the beneficial or adverse effects of non-nutritive sucking in preterm infants by:
i) identifying all experimental and quasi-experimental trials of non-nutritive sucking in preterm infants
ii) assessing the methodologic quality of each study
iii) estimating overall effects of non-nutritive sucking on clinically relevant outcomes such as:
All experimental and quasi-experimental studies in which non-nutritive sucking in preterm infants was compared to no provision of non-nutritive sucking were identified.
All infants born at < 37 weeks post-conceptual age. Studies involving both preterm and term (greater than or equal to 37 weeks) were excluded.
Non-nutritive sucking involving the use of a pacifier. The intervention occurred before, during or after feeding by a naso/oro-gastric tube; before or after bottle feeding; or outside of feeding times.
a) weight gain
b) length of hospital stay
c) transition to oral/nipple feedings
d) heart rate and oxygen saturation/oxygenation
e) activity/behaviour
f) any other clinically relevant outcomes
Computerized searches were conducted by both reviewers. MEDLINE and CINAHL databases back to 1976 and the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1, 2005) were searched using the following MeSH headings: infant, premature; intensive care units, neonatal; enteral nutrition; sucking behaviour; infant nutrition; gastric emptying; growth; parenteral nutrition; bottle feeding; infant care; infant, low birth weight; somatostatin; crying; oxygen; child development; physical stimulation; taste; infant, newborn; feeding behaviour. These headings were chosen from the articles in the meta-analysis by Steer et al (Steer 1992). The following text words were also searched: non(tw) and nutritive(tw) and suck(tw). Trials evaluating the effect of NNS on pain in the preterm infant were excluded.
All potentially relevant titles and abstracts identified by either reviewer were retrieved. The reference lists/bibliographies of each article were reviewed independently for additional relevant titles and these were also retrieved. The list of all relevant articles was sent to two major authors in this area. They were asked if they knew of any other published or unpublished studies relevant to the area that have not been included in the original list.
The systematic review followed the method described in the Cochrane Collaboration Handbook. All of the articles that were retrieved from the complete search were assessed for relevance independently by the two reviewers. Criteria for relevance included trials that utilized: experimental or quasi-experimental designs, intervention of non-nutritive sucking in preterm infants, and clinically relevant outcomes. The articles that met all relevance criteria were assessed for methodological quality based on the criteria stated in the section below. A kappa statistic was calculated on the agreement between both reviewers at two stages in the review process: in the assessment of relevance of the articles and in the assessment of the methodologic quality of the relevant articles. For relevance of the articles, the kappa was 0.62, with 87% agreement. For methodologic quality the kappa was 0.61, with 82% agreement. Differences were resolved through discussion and were mainly related to oversights on the part of one of the readers.
Those articles judged to have the appropriate quality by both reviewers were included in the analysis. Data were extracted independently by the two reviewers. Missing data were obtained from the original authors where possible. No subgroup analyses were performed because of the small number of studies related to the relevant outcomes. The study by Yu 1999 was assessed by only one reviewer because of the language limitation.
All of the 21 studies that met the relevance criteria were included in the review. It should be noted that none of the 21 studies met all of the methodologic quality criteria. Of the 21 studies, 15 were randomized controlled trials and six utilized non-randomized designs. The total sample sizes in the studies ranged from 10 to 59 infants. The intervention of non-nutritive sucking was delivered through the use of a pacifier and occurred during gavage feeding, before and/or after bottle feeding, or not related to feeding. A large number of outcomes were utilized in the 21 studies but only a few were common among them. The overall review includes both randomized and non-randomized studies, although only randomized studies are included in the data analysis. Details of each included study are in the table, Characteristics of Included Studies.
Thirteen studies were excluded from the review. The reason for exclusion in all cases was because they did not meet one or more of the relevance criteria (see Characteristics of Excluded Studies). The relevance of the studies in these cases could not be determined by the title or abstract and required a review of the entire article.
The included (and excluded) studies were assessed using the following key criteria: blindness of randomization, blindness of intervention, complete follow-up and blinding of outcome measurement. Additional criteria of study quality included: evidence of cointervention, objective criteria of measuring outcomes and defined exclusion/inclusion criteria. The non-nutritive sucking intervention cannot be blind to those providing care, but should be blind to the assessors of the outcomes. Of the 15 RCTs, eight utilized a cross-over design where the infants served as their own controls. These studies were not included in the meta-analysis, but were included in the results. Blindness of randomization was evident in only six of the studies. In only one study was it clear that the outcome assessors were blinded. Complete follow-up occurred in all of the studies.
This review consisted of 21 studies, 15 of which were randomized controlled trials. The data analysis involved seven clinical outcomes, although only four included more than one study in the outcome category. The results of the tests of heterogeneity of the analyses utilizing more than one study were significant for only one outcome, heart rate. The analyses of the studies for the remaining three outcomes were all non-significant for heterogeneity.
The first of those four outcomes is weight gain in grams per day. Three randomized trials were included in the meta-analysis. Two of the trials showed no difference between groups during a two-week study period (Ernst 1989; Mattes 1996). The third trial demonstrated a trend favouring the control group, although the time of data collection is not specified (Field 1982). The overall effect was non-significant (WMD 1.57 g/day, 95% CI -0.37,3.50). A fourth randomized trial, Bernbaum (1983), demonstrated a significant difference in weight gain favouring the treatment group by the second week and the difference remained significant throughout the study period (six weeks). This study was not included in the meta-analysis because the standard deviations were unavailable from the authors. In addition, two non-randomized studies utilized weight gain as an outcome. Both studies showed no difference in weight gain between the treatment and control groups (Measel 1979; Sehgal 1990). Based on the results of the randomized and non-randomized studies, there is no clear benefit of NNS with respect to weight gain in grams per day.
Heart rate was measured in four randomized trials. Neither study by Pickler (Pickler 1992; Pickler 1996) showed a difference between groups. One study by McCain (1995) also demonstrated no difference but her earlier study showed a difference in favour of the treatment group (McCain 1992). Although statistically significant, the difference in heart rate was not clinically significant. The overall effect of the analysis, however, showed no statistically significant difference between groups (WMD -1.4 beats/min, 95% CI -5.9, 3.1). It should be noted that this analysis was significant for heterogeneity so the results must be viewed with caution.
Three randomized trials measured oxygen saturation as an effect of NNS. None of the individual trials showed a significant difference between groups, but the overall effect approached significance in favour of the control group (WMD 1.0 %, 95% CI -0.04, 2.1). As with heart rate, the differences were not clinically significant.
Two randomized trials examined the effect of NNS on length of hospital stay (in days). Field (1982) found no difference between groups, while Bernbaum (1983) demonstrated a significant reduction in length of stay. The overall analysis did reveal a significant difference in length of hospital stay (WMD -7.1 days, CI -12.6, -1.7). Although Field (1982) did not demonstrate a significant difference in length of hospital stay, she did report a positive economic impact of NNS on hospital costs.
There are a number of outcomes associated with NNS that have been reported in single studies. Three of these studies have been included in the table of comparisons because of their clinical relevance and because they are randomized trials. DeCurtis 1986 found no significant difference between experimental and control groups with respect to intestinal transit time (in hours) or energy intake (kcal/kg/day). In contrast, another randomized study by Bernbaum 1983 showed a significantly increased transit time in infants receiving NNS by the end of the first week and persisted throughout the remaining four weeks. This study was not included in the meta-analysis because the standard deviations were unavailable from the authors. Mattes 1996 showed no difference in post-conceptual age at full oral feeds (in days).
Ernst 1989 studied the effect of NNS on energy balance and DeCurtis 1986 studied nutrient retention. Both studies were done in tube fed babies. Ernst (1989) found NNS to have no effect on energy expenditure, stool excretion or stool fat. DeCurtis (1986) reported that NNS had no effect on stool energy and stool fat. Three randomized trials reported no effect of NNS on gastric emptying (Ernst 1989; Szabo 1985; Widstrom 1988). No data were available for these trials so that a meta-analysis was not possible.
Widstrom 1988 and Kanarek 1992 studied the effect of NNS on specific hormones in tube fed infants. Kanarak 1992 found that NNS has no apparent effect on the blood concentrations of motilin, gastrin, insulin or insulin-like growth factor 1, three days after commencing feeds. Widstrom 1988 reported a significant decrease in somatostatin levels with NNS.
DiPietro 1994 reported the effect of NNS on physiological parameters in tube fed infants. She found NNS to have no effect on vagal tone, oxygen saturation and heart rate. However, Burroughs 1978 did report a significant improvement in TcPO2 readings in the infants receiving NNS that was not associated with feeding.
The effect of NNS on the transition from tube feeds to bottle feeds has been reported by Field 1982 and Sehgal 1990. Field 1982 found that infants offered NNS had significantly fewer days of tube feeding (three-day difference). Sehgal 1990 reported that the time for transition from tube feeds to bottle feeds was significantly reduced by 1.6 days in infants receiving NNS. Widstrom 1988 also reported a significant decrease in tube feeding time in infants receiving NNS. Yu 1999 found that feeding performance was improved in the NNS group. With NNS there was significantly more intake within the first five minutes, more total amount of feeding, less feeding time and a faster feeding rate. Pickler 2004 found no statistically significant effect of NNS on the amount of formula consumed per minute of feeding.
DiPietro 1994 and Field 1982 both analyzed the effect of NNS on behavioral state during tube feedings. The data, however, cannot be combined as the authors used different measurement scales. DiPietro 1994 used Anderson's 12-level Behavioral State Scale (ABSS) and found that infants receiving NNS spent significantly less time in fussy and active awake states during and after a tube feed, and settle more quickly into a sleep state. Field 1982 used the Brazelton Neonatal Behavioral Assessment Scale (NBAS) and found that NNS had no effect on behavioral state. DiPietro 1994 found that infants receiving NNS exhibited less defensive behaviors during tube feeding. Yu 1999 found that preterm infants receiving NNS before bottle feeding spent significantly more time in a quiet awake state and less time in active sleep, drowsiness, active awake and crying states. Three and five minutes of NNS showed the same effect on behavioral states and feeding. Pickler 2004 analyzed the effect of NNS on behavioral state before, during and after bottle feeding and demonstrated no effect on behavioral state.
In summary, the results of this review demonstrated a significant effect on the length of hospital stay favouring the experimental group. Several studies also demonstrated a positive effect from NNS on: decreased somatostatin levels; increased TcPO2 readings; decreased time to establish nipple feeds; better bottle feeding performance; decreased time in fussy and awake states; settled more quickly following feeds; and exhibited less defensive behaviors during tube feeding. The results of this review revealed no significant effect of NNS on: weight gain; energy intake; heart rate; oxygen saturation; intestinal transit time; time to full oral feeds; energy expenditure; stool excretion or stool fat; stool energy; gastric aspirates; blood concentrations of motilin, gastrin, insulin or insulin-like growth factor-1; vagal tone; or behavioral state.
The results of this review demonstrated a significant benefit of NNS on length of hospital stay (in days). The review did not reveal a benefit of NNS with respect to the other major clinical variables (weight gain, energy intake, heart rate, oxygen saturation, intestinal transit time, and post-conceptual age at full oral feeds).
The review identified other positive clinical outcomes of NNS: transition from tube to bottle feeds, better bottle feeding performance. No negative outcomes were reported in any of the studies. There were a number of limitations of the presently available evidence:
1. Design Limitations
Although 15 of the 21 studies reviewed were randomized trials, eight
were cross-over designs. Cross-over designs present at least two limitations
in assessing the effects of non-nutritive sucking. The appropriate length
of time to wash out the effects of the NNS intervention prior to crossover
is not known; and late effects, e.g. time to full feeding, cannot be assessed.
In only six trials was the randomization clearly blinded. Because of the
nature of the intervention, blinding was not possible. However, blinding
of outcome assessors, although possible was evident in only one of the studies
reviewed.
2. Outcome Variability
Meta-analysis was limited in this review due to the large variation in
outcomes and limited number of randomized trials that were included in each
outcome. Although many of the studies measured similar outcomes, the outcomes
were too dissimilar to be included in a meta-analysis. Alternatively, the
authors reported the significance level but no specific data were provided.
In addition, the context of the measurement of the outcomes varied greatly
among studies. For example, outcomes were measured before, during or after
gavage feeding; before or after bottle feeding; or not associated with feeding.
Because of the small number of studies in each category that measured comparable
outcomes, all studies were combined regardless of context. These contextual
differences should be noted when considering the results of the review.
3. Lack of long-term data
The studies reviewed included no short- or long-term negative outcomes.
The outcomes chosen were either found to have a positive short-term effect
or no effect as a result of NNS. Examples of potential negative effects would
be the effect of NNS on breastfeeding or on incidence of later oral aversion.
The negative impact of NNS was not measured in any of the studies. None of
the infants in the studies reviewed were followed past hospital discharge.
NNS demonstrated a benefit in only one of the major outcomes measured. There were also a number of short-term positive results for several of the secondary outcomes. No negative effects of NNS were studied, however.
The main results of the meta-analysis, and from the single and non-randomized studies indicate that NNS decreases length of hospital stay in preterm infants, and appears to facilitate the transition to full oral/bottle feeds and bottle feeding performance in general. Infants receiving NNS exhibited less defensive behaviors during tube feedings, spent significantly less time in fussy and active states during and after tube feedings, and settled more quickly into sleep states. Positive effects of NNS on behavioral state were not consistently demonstrated.
Although a number of outcomes demonstrated no difference with or without NNS, there do not appear to be any short-term negative effects as a result of this intervention. Based on the available evidence, NNS in preterm infants would appear to have some clinical benefit. Although not specifically studied, NNS does not appear to have any negative effect, short-term. No long-term data on the effects of NNS are presently available.
In view of the fact that there are no long-term data, further investigations are recommended. In order to facilitate meta-analysis of these data, future research in this area should involve outcome measures consistent with those used in previous studies. In addition, published reports should include all relevant data.
We would like to thank Patricia Austin for her assistance in retrieval of the references for this review.
| Study | Methods | Participants | Interventions | Outcomes | Notes | Allocation concealment |
| Bernbaum 1983 | Randomized Blinding of randomization - Yes Blinding of intervention - No Blinding of outcome assessors - Can't tell Complete follow-up - Yes | Appropriate for gestational age Birth weight < 1.5kg Sample size = 30 (15 in each group) | Experimental group: Pacifier during tube feed only Control group: No pacifier | Weight, length, head circumference Gastrointestinal transit time Sucking behaviour Time taken for first 5 bottle feeds Days for transition to oral feeds Length of hospital stay | Random envelope assignment (information supplied by author) | A |
| Burroughs 1978 | Pretest-posttest design Blinding of intervention - No Blinding of outcome assessors - Can't tell Complete follow-up - Yes | Gestational age < 37 weeks Birth weight > 1.0kg Sample size = 11 | No sucking (pretreatment), pacifier (treatment), no sucking (post-treatment) | TcPO2 measured pre-intervention, during the intervention, post-intervention. | D | |
| DeCurtis 1986 | Randomized, crossover Blinding of randomization - can't tell Blinding of intervention - No Blinding of outcome assessors - Can't tell Complete follow-up - Yes | Mean gestational age - 28.8 weeks Mean birthweight - 1.111kg Sample size = 10 | Experimental group: Pacifier during tube feeds. Control group: No pacifier. | Energy and nitrogen balance Net nitrogen utilization Fat absorption Gastrointestinal transit time | B | |
| DiPietro 1994 | Randomized, crossover Blinding of randomization - No Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | Gestational age - 1.0 - 2.0kg Birth weight < 34 weeks Sample size = 36 | Experimental group: Pacifier during tube feed and after feed x 15 minutes or until in sleep state x 5 minutes. Control group: No pacifier | Behaviour Heart rate Vagal tone Oxygen saturation | C | |
| Ernst 1989 | Randomized Blinding of randomization - Can't tell Blinding of intervention - No Blinding of outcome assessors - Can't tell Complete follow-up - Yes | Gestational age < 30 weeks Birth weight < 1.4kg Sample size = 18 Number randomized to each group=9 | Experimental group: Pacifier during feed and after feed for 30 minutes. Control Group: No pacifier. Both groups: No pacifier between feedings. Intake was held constant in both groups. | Anthropometric measures Serum proteins Gastrointestinal transit time Energy and fat excretions (8 subjects) Energy expenditure (8 subjects) | B | |
| Field 1982 | Randomized, stratified Blinding of randomization - Can't tell Blinding of intervention - No Blinding of outcome assessors - can't tell Complete follow-up - Yes | Gestational age < 35 weeks Birth weight < 1.8kg Sample size = 57 Number randomized to each group=27(Control), 30(Exp) | Experimental group: Pacifier during all tube feeds Control group: No pacifier during tube feeds Both groups: Pacifier offered between feeds | Behaviour (assessed when in open crib) Feeding behaviour Days of tube feeding Number of tube feeds Daily weight gain Length of hospital stay Hospital cost | B | |
| Gill 1988 | Randomized Blinding of randomization - Yes Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | Gestational age < 34 weeks Birth weight < 2.0kg Sample size = 24 Number randomized to each group=12 | Experimental group: Pacifier before bottle feed x 5 minutes Control group: No pacifier | Behaviour | A | |
| Gill 1992 | Randomized Blinding of randomization - Yes Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | Gestational age < 34 weeks Birth weight < 2.0kg Sample size = 42 Number randomized to each group=21 | Experimental group: Pacifier before bottle feed x 5 minutes Control group: No pacifier | Behaviour | A | |
| Kanarek 1992 | Randomized Blinding of randomization - Yes Blinding of intervention - No Blinding of outcome assessors - Can't tell Complete follow-up - Yes | 30-35 weeks gestational age Receiving bolus or continuous feeds Sample size = 21 Number randomized to each group=11(Control), 10(Exp) | Experimental group: Pacifier during and after feeds and when awake. Control group: No pacifier. Stroked when restless. | Gastrin Motilin Insulin Insulin-like growth factor | A | |
| Mattes 1996 | Randomized Blinding of randomization - Yes Blinding of intervention - No Blinding of outcome assessors - Can't tell Complete follow-up - Yes | Gestational age < 34weeks Birth weight > 1.25kg Sample size = 42 Number randomized to each group=14 | Experimental group 1: Sweet edible pacifier during tube feeds Experimental group 2: Latex pacifier during tube feeds Control group: No pacifier. Maternal heart beat played during tube feeds | Anthropometric measurements Sucking measures Age at full oral feeds | Latex pacifier group used as experimental group for analysis | A |
| McCain 1992 | Randomized, multiple crossover Blinding of randomization - No Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | Mean gestational age - 31.6 weeks Mean birth weight - 1.649kg Sample size = 20 | Experimental group 1: Pacifier before bottle feeds x 10 minutes Experimental group 2 : Pacifier before bottle feeds with stroking/rocking x 10 minutes Control group: No pacifier | Behaviour Heart rate | C | |
| McCain 1995 | Randomized, crossover Blinding of randomization - No Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | Mean gestational age - 31.6 weeks Mean birth weight - 1.649kg Sample size = 20 | Experimental group: Pacifier before bottle feeds x 10 minutes Control group: No pacifier | Behaviour Heart rate Length of feeding time/oral intake | The samples in McCain 1992 and 1995 are the same. McCain 1992 was the first phase of a study analyzing outcomes prior to feeds. This study analyzed the outcomes during feeds. | C |
| Measel 1979 | Alternate sequential series and matching Blinding of intervention - No Blinding of outcome assessors - Yes Complete follow-up - Yes | Gestational age 28 - 34 weeks Birth weight > 1.0kg Sample size = 59 (30 in Control and 29 in Exp groups) | Experimental group: Pacifier during tube feed and 5 minutes after feed Control group: No pacifier during feed or 5 minutes after feed Both groups: Pacifier between feeds PRN | Weight gain Readiness for bottle feeds Feeding performance during first bottle feed | D | |
| Pickler 1992 | Method of allocation - uncertain (author clarification being sought) Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | Gestational age - 26 - 34 weeks Birth weight - 0.81- 1.99kg Sample size = 20 (10 in each group) | Expermental group: Pacifier before bottle feed x 5 minutes and after bottle feed x 5 minutes Control group: No pacifier | Behaviour Feeding performance Oxygen saturation Heart rate | B | |
| Pickler 1996 | Randomized, crossover Blinding of randomization - Yes Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | Mean gestational age - 29.5 weeks Mean birth weight - 1.3577kg Sample size = 13 | Experimental group: Pacifier pre-bottle feed x 2 minutes prior to 2 feeds Control group: No pacifier | Behaviour Feeding performance Heart rate Oxygen saturation | A | |
| Pickler 2004 | Randomized, crossover Blinding of randomization - No Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | Gestational age <32 weeks No known cognitive, neurologic, cardiovascular, gastrointestinal or craniofacial disorder Sample size = 13 (data collection completed on 10) | Experimental group: Pacifier pre-bottle feed x 2 minutes prior to 1 feed Control group: No pacifier for 1 feed | Behavioral state | C | |
| Sehgal 1990 | Method of allocation - uncertain (author clarification being sought) Blinding of intervention - No Blinding of outcome assessors - Can't tell Complete follow-up - Yes | Gestational age < 35 weeks Birth weight < 1.8kg Sample size = 40 (20 in each group) | Experimental group: Pacifier during tube feed x 3 minutes Control group: No pacifier | Anthropometric measures Length of nursery stay Transition time to bottle feeds Stool frequency Time to ingest first 8 bottle feeds | B | |
| Szabo 1985 | Randomized, multiple cross-over Blinding of randomization - Yes Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | Gestational age - 33-36 weeks Birthweight: < 1500 g Sample size = 10 | Experimental group: Pacifier during tube feed for 5 minutes Control group: No pacifier Group III: Nutritive suck for 1/2 feed | Gastric emptying | Group III not used in analysis | A |
| Widstrom 1988 | Randomized, crossover Blinding of randomization - No Blinding of intervention - No Blinding of outcome assessors - Can't tell Complete follow-up - Yes | Mean gestational age - 32.3 weeks Mean birth weight - 1.826kg Taking 2-4 bottle feeds/day Sample size = 8 | Experimental group: Pacifier 15 minutes before tube feed and during feed. Pacifier offered between feeds. Control group: No pacifier | Somatostatin level Gastrin level pH | C | |
| Woodson 1988a | Non-randomized cross-over Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | AGA preterm infants receiving intermediate care Sample size = 24 | NNS Period: Pacifier given 30 minutes after bottle feeding followed by no pacifier No NNS Period: No pacifier after bottle feed x 30 minutes followed by pacifier | Heart rate | D | |
| Woodson 1988b | Non-randomized cross-over Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | AGA preterm infants receiving intermediate level care Sample size = 13 | Pacifier given between every other bottle feed x 12 hours | Heart rate | Outcomes assessed between feeds | D |
| Yu 1999 | Randomized cross-over Blinding of intervention - No Blinding of outcome assessors - No Complete follow-up - Yes | Gestational age < 37weeks. Birth weight < 2.0kg. Sample size = 11. 176 events analyzed (4 feeds/day x 4 days). | Experimental groups: Group 1 recieved 3 minutes of NNS prior to bottle feeding: Group 2 received 5 minutes of NNS prior to bottle feeding. Control Group: No NNS | Amount of feeding in first 5 minutes Amount of total feeding Feeding time Feeding rate Behavioral state | English translation from Chinese required. | C |
| Study | Reason for exclusion |
| Bingham 2003 | Non-nutritive sucking is not the intervention |
| Burroughs 1981 | Not experimental or quasi-experimental |
| Daniels 1988 | Not experimental or quasi-experimental |
| Kimble 1992 | Term infants No clinical outcomes Not experimental or quasi-experimental |
| Marchini 1987 | Term infants |
| Miller 1993 | Term infants |
| Narayanan 1991 | No intervention |
| Neeley 1979 | Term infants |
| Orenstein 1988 | Term infants |
| Paludetto 1984 | Not experimental or quasi-experimental |
| Paludetto 1986 | Not experimental or quasi-experimental |
| Standley 2003 | Non-nutritive sucking not the primary intervention |
| Woodson 1985 | Term infants Not experimental or quasi-experimental |
Bernbaum JC, Pereira GR, Watkins JB, Peckham GJ. Nonnutritive sucking during gavage feeding enhances growth and maturation in premature infants. Pediatrics 1983;71:41-5.
Burroughs 1978 {published data only}
Burroughs AK, Asonye UO, Anderson-Shanklin GC, Vidyasagar D. The effect of nonnutritive sucking on transcutaneous oxygen tension in noncrying, preterm neonates. Research in Nursing & Health 1978;1:69-75.
DeCurtis 1986 {published data only}
De Curtis M, McIntosh N, Ventura V, Brooke O. Effect of nonnutritive sucking on nutrient retention in preterm infants. Journal of Pediatrics 1986;109:888-90.
DiPietro 1994 {published data only}
DiPietro JA, Cusson RM, Caughy MO, Fox NA. Behavioral and physiologic effects of nonnutritivie sucking during gavage feeding in preterm infants. Pediatric Research 1994;36:207-14.
Ernst 1989 {published data only}
Ernst JA, Rickard KA, Neal PR, Yu PL, Oei, TO, Lemons, JA. Lack of improved growth outcome related to nonnutritive sucking in very low birth weight premature infants fed a controlled nutrient intake: A randomized prospective study. Pediatrics 1989;83:706-16.
Field 1982 {published data only}
Field T, Ignatoff E, Stringer S, Brennan J, Greenberg R, Widmayer S, Anderson GC. Nonnutritive sucking during tube feedings: Effects on preterm neonates in an intensive care unit. Pediatrics 1982;70:381-4.
Gill 1988 {published data only}
Gill NE, Behnke M, Conlon M, McNeely JB, Anderson GC. Effect of nonnutritive sucking on behavioral state in preterm infants before feeding. Nursing Research 1988;37:347-50.
Gill 1992 {published data only}
Gill NE, Behnke M, Conlon M, Anderson GC. Nonnutritive sucking modulates behavioral state for preterm infants before feeding. Scandinavian Journal of Caring Sciences 1992;6:3-7.
Kanarek 1992 {published data only}
Kanarek KS, Shulman D. Non-nutritive sucking does not increase blood levels of gastrin, motilin, insulin and insulin-like growth factor 1 in premature infants receiving enteral feedings. Acta Paediatrica 1992;81:974-7.
Mattes 1996 {published data only}
Mattes RD, Wager-Page S, Beauchamp G, Bernbaum J, Stallings V, Pereira G, Gibson E, Russell P, Bhutani V. Effects of sweet taste stimulation on growth and sucking in preterm infants. Journal of Obstetric, Gynecologic, and Neonatal Nursing 1996;25:407-14.
McCain 1992 {published data only}
McCain GC. Facilitating inactive awake states in preterm infants: A study of three interventions. Nursing Research 1992;41:157-60.
McCain 1995 {published data only}
McCain GC. Promotion of preterm infant nipple feeding with nonnutritive sucking. Journal of Pediatric Nursing 1995;10:3-8.
Measel 1979 {published data only}
Measel CP, Anderson GC. Nonnutritive sucking during tube feedings: Effects on clinical course in premature infants. Journal of Obstetric, Gynecologic, and Neonatal Nursing 1979;8:265-72.
Pickler 1992 {published data only}
Pickler RH, Higgins KE, Crummette BD. The effect of nonnutritive sucking on bottle-feeding stress in preterm infants. Journal of Obstetric, Gynecologic, and Neonatal Nursing 1992;22:230-4.
Pickler 1996 {published data only}
Pickler RH, Frankel HB, Walsh KM, Thompson NM. Effects of nonnutritive sucking on behavioral organization and feeding performance in preterm infants. Nursing Research 1996;45:132-5.
Pickler 2004 {published data only}
Pickler RH, Reyna BA. Effects of non-nutritive sucking on nutritive sucking, breathing and behavior during bottle feedings of preterm infants. Advances in Neonatal Care 2004;4:226-34.
Sehgal 1990 {published data only}
Sehgal SK, Prakash O, Gupta A, Mohan M, Anand NK. Evaluation of beneficial effects of nonnutritive sucking in preterm infants. Indian Pediatrics 1990;27:263-6.
Szabo 1985 {published data only}
Szabo JS, Hillemeier AC, Oh W. Effect of non-nutritive and nutritive suck on gastric emptying in premature infants. Journal of Pediatric Gastroenterology and Nutrition 1985;4:348-51.
Widstrom 1988 {published data only}
Widstrom AM, Marchini G, Matthiesen AS, Werner S, Winberg J, Uvnan-Moberg K. Nonnutritive sucking in tube-fed preterm infants: Effects on gastric motility and gastric contents of somatostatin. Journal of Pediatric Gastroenterology and Nutrition 1988;7:517-23.
Woodson 1988a {published data only}
Woodson R, Hamilton C. The effect of nonnutritive sucking on heart rate in preterm infants. Developmental Psychobiology 1988;21:207-13.
Woodson 1988b {published data only}
Woodson R, Hamilton C. The effect of nonnutritive sucking on heart rate in preterm infants. Developmental Psychobiology 1988;21:207-13.
Yu M, Chen Y. The effects of nonnutritive sucking on behavioral state and feeding in premature infants before feeding. Nursing Research (China) 1999;7:468-78.
Bingham PM, Abassi S, Sivirei E. A pilot study of milk odor effect on non-nutritive sucking by premature newborns. Archives of Pediatric and Academic Medicine 2003;157:72-5.
Burroughs 1981 {published data only}
Burroughs AK, Anderson GC, Patel MK, Vidyasagar D. Relation of nonnutritive sucking pressures to tcPO2 and gestational age in preterm infants. Perinatol Neonatol 1981;2:54-62.
Daniels 1988 {published data only}
Daniels H, Devlieger H, Casaer P, Callens M, Eggermont E. Nutritive and non-nutritive sucking in preterm infants. Journal of Developmental Psychology 1986;8:117-21.
Kimble 1992 {published data only}
Kimble C. Nonnutritive sucking: Adaptation and health for the neonate. Neonatal Network 1992;11:29-33.
Marchini 1987 {published data only}
Marchini G, Lagercrantz H, Feuerberg Y, Winberg J, Uvnas-Moberg K. The effect of non-nutritive sucking on plasma insulin, gastrin and somatostatin levels in infants. Acta Paediatrica Scandinavica 1987;76:573-8.
Miller 1993 {published data only}
Miller HD, Anderson GC. Nonnutritive sucking: Effects on crying and heart rate in intubated infants requiring assisted mechanical ventilation. Nursing Research 1993;42:305-7.
Narayanan 1991 {published data only}
Narayanan I, Mehta R, Choudhury DK, Jain BK. Sucking on the 'emptied' breast: non-nutritive sucking with a difference. Archives of Disease in Childhood 1991;66:241-4.
Neeley 1979 {published data only}
Neeley CA. Effects of nonutritive sucking upon the behavioral arousal of the newborn. In Anderson GC, Raff B (Eds) Newborn behavioral organization: Nursing research and implications. Birth Defects Original Article Series 1979;XV:173-200.
Orenstein 1988 {published data only}
Orenstein SR. Effect of nonnutritive sucking on infant gastroesophageal reflux. Pediatric Research 1988;24:38-40.
Paludetto 1984 {published data only}
Paludetto, R, Robertson SS, Hack M, Shivpuri CR, Martin RJ. Transcutaneous oxygen tension during nonnutritive sucking in preterm infants. Pediatrics 1984;74:539-42.
Paludetto 1986 {published data only}
Paludetto R, Robertson SS, Martin RJ. Interaction between nonnutritive sucking and respiration in preterm infants. Biology of the Neonate 1986;49:198-203.
Standley 2003 {published data only}
Standley JM. The effect of music-reinforced non-nutritive sucking on feeding rate of premature infants. Journal of Pediatric Nursing 2003;18(3):169-73.
Woodson 1985 {published data only}
Woodson R, Drinkwin J, Hamilton C. Effects of nonnutritive sucking on state and activity: Term-preterm comparisons. Infant Behaviour and Development 1985;8:435-41.
* indicates the primary reference for the study
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Chey WY, Lee KY. Motilin. Clinics in Gastroenterology 1980;9:645-56.
Dreier T, Wolff P, Cross EE, Cochran WD. Patterns of breath intervals during non-nutritive sucking in full-term and 'at risk' preterm infants with normal neurological examinations. Early Human Development 1979;2:187-99.
Dubignon JM, Campbell D, Partington MW. The development of non-nutritive sucking in premature infants. Biology of the Neonate 1969;14:270-8.
Goldson E. Non-nutritive sucking in the sick infant. Journal of Perinatology 1987;7:30-4.
Hamosh M. A review. Fat digestion in the newborn: Role of lingual lipase and preduodenal digestion. Pediatric Research 1979;13:615-22.
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Kimble C. Nonnutritive sucking: Adaptation and health for the neonate. Neonatal Network 1992;11:29-33.
Mathew OP, Clark ML, Pronske MH. Breathing pattern of neonates during non-nutritive sucking. Pediatric Pulmonology 1985;1:204-6.
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Miller LK. Effects of auditory stimulation upon non-nutritive sucking by premature infants. Perceptual and Motor Skills 1975;40:879-85.
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Sameroff A. Nonnutritive sucking in newborns under vusual and auditory stimulation. Child Development 1967;38:443-52.
Schwartz R, Moody L, Yarandi H, Anderson G. A meta-analysis of critical outcome variables in non-nutritive sucking in preterm infants. Nursing Research 1987;36:292-5.
Semb G, Lipsitt LP. The effects of acoustic stimulation on cessation and initiation of non-nutritive sucking in neonates. Journal of Experimental Child Psychology 1968;6:585-97.
Steer PA, Lucas A, Sinclair JC. Feeding the low birthweight infant. In: Sinclair JC, Bracken MB, editor(s). Effective Care of the Newborn Infant. Oxford: Oxford University Press, 1992:128-130.
Wiener I, Khalil T, Thompson JC, Rayford PL. Gastrin. In: Thompson JC, editor(s). Gastrointestinal Endocrinology. New York: McGraw Hill, 1987:194-212.
Wolff P. The interaction of state and non-nutritive sucking. In: Third Symposium on Oral Sensation and Perception: The mouth of the infant. Illinois: Charles Thomas, 1972:293-310.
Wolff PH, Simmons MA. Nonnutritive sucking and response thresholds in young infants. Child Development 1967;38:631-8.
Pinelli J, Symington A. Non-nutritive sucking in premature infants (Cochrane Review). In: The Cochrane Library, Issue 4, 1998. Oxford: Update software.
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| Comparison or outcome | Studies | Participants | Statistical method | Effect size |
|---|---|---|---|---|
| 01 Nonnutritive sucking vs control in premature infants | ||||
| 01 Weight gain (g/day) | 3 | 103 | WMD (fixed), 95% CI | 1.57 [-0.37, 3.50] |
| 02 Heart rate (beats/min) | 4 | 126 | WMD (fixed), 95% CI | -1.42 [-5.90, 3.07] |
| 03 Oxygen saturation (%) | 3 | 72 | WMD (fixed), 95% CI | 1.04 [-0.04, 2.13] |
| 04 Length of hospital stay (days) | 2 | 87 | WMD (fixed), 95% CI | -7.15 [-12.60, -1.70] |
| 05 Intestinal transit time (hours) | 1 | 20 | WMD (fixed), 95% CI | -1.00 [-7.14, 5.14] |
| 06 Energy intake (kcal/kg/day) | 1 | 20 | WMD (fixed), 95% CI | -2.00 [-21.36, 17.36] |
| 07 Post-conceptional age at full oral feeds (days) | 1 | 28 | WMD (fixed), 95% CI | -1.70 [-46.06, 42.66] |
| The review is published as a Cochrane review in The
Cochrane Library, Issue 4, 2005, (see http://www.thecochranelibrary.com for
information). Cochrane reviews are regularly updated as new evidence emerges
and in response to comments and criticisms, and The Cochrane Library should
be consulted for the most recent version of the Review. |