Oral Care Performed with Breast Milk in Preterm Newborns Fed by Tube: A Randomized Controlled Study

Abstract

Objective:

This study examined the effect of breast milk on oral care practices in neonatal intensive care units.

Methods:

This study involved 64 preterm infants (intervention/breast milk: 32, control/distilled water: 32) and was carried out with a prospective, parallel, randomized controlled design. The “Newborn Oral Health Assessment Tool (NOHAT)” was used to assess oral care. The Mann–Whitney U test, continuity correction test, Fisher’s exact test, independent-samples T test, and Wilcoxon signed ranks test were used to analyze the data.

Results:

Examining the oral care performed using breast milk and distilled water with NOHAT scores, it was determined that there was a significant difference in the intervention group (p < 0.05).

Conclusions:

It is recommended to use breast milk for oral care.

Introduction

Newborn oral health is critical in terms of basic functions such as nutrition, taste, breathing, gastrointestinal flora, and defense. The main purpose of oral care is to keep the mouth and lips clean, soft, moist, and healthy. This care is especially important for premature newborns. Well-assessed and appropriately given oral care reduces the risk of oral and systemic infections by keeping the oral mucosa clean and healthy and providing a positive oral experience. Moreover, it supports the early sensory development of taste and smell.^1,2

Premature babies, particularly those with very low birth weight (VLBW; <1,500 g), are at high risk for disruption of oral integrity in neonatal intensive care units (NICUs).³ Premature babies, who have not started oral feeding and are being fed through an orogastric tube, may develop oral cavity infections, disrupting the integrity of the oral mucosa. Undesired conditions such as dryness, pain, redness in the mouth and lips, and decreased saliva secretion may develop in babies who do not receive proper oral care.^4,5 Dry and cracked lips can harbor pathogens and increase the risk of infection.^1,3,5

An effective oral and mucosal assessment should be performed at each oral care session. Lips and corners of the mouth should be smooth, pink, and moist, and there should be no dryness, cracks, ulceration, or bleeding. The tongue should be pink and moist, and papillae (taste buds) should appear shiny and be checked for signs of cracking, fissures, oral candida, or redness. Saliva should be thin and watery. This assessment should be done regularly using an oral assessment tool and recorded.²

The early sensory experiences of premature newborns differ significantly from those of term newborns. Introducing premature babies to breast milk early on to experience the taste and traditional feeding behaviors while being fed through a nasogastric tube offers significant benefits in terms of positive taste and smell learning experiences. This situation is also a positive experience for parents.^1,6

Providing oral care with breast milk for premature babies can help meet their various needs, and it can also support their development. Oral care performed with breast milk can even be tolerated by newborns with VLBWs. The contact of colostrum with the mouth and oropharyngeal mucosa provides immune protection through the anti-inflammatory and proinflammatory cytokines, lactoferrins, and oligosaccharides abundant in the mother’s colostrum and milk and also supports the stimulation of oropharyngeal receptors. This interaction increases gastrointestinal motility, secretion, and absorption capacity.^3,7

Oral care performed using breast milk or colostrum does not require babies to swallow the milk but allows them to absorb most of the beneficial components in colostrum and breast milk through the oral mucosa.^2,8 When breast milk matures, the immune system-supporting properties are still present, although not as high in the colostrum. The breast milk the baby can swallow is usually small, ∼0.2 mL; it is divided between both cheeks and placed on the oral mucosa. Sterile cotton swabs or oral applicators can be used for this purpose.⁶ Colostrum is recommended for oral care in intubated babies. It is very important to keep the oral–pharyngeal mucosa moist for maintaining mucosal integrity.⁹

A meta-analysis study revealed that oropharyngeal colostrum application reduces the rates of necrotizing enterocolitis, late-onset sepsis, feeding intolerance, and death, shortens the duration of full enteral feeding, and leads to faster recovery of birth weight in premature babies. Therefore, given the current evidence, it is recommended that clinical health care personnel administer oropharyngeal colostrum to premature babies.¹⁰ In addition, studies using colostrum and breast milk reported a decrease in late-onset sepsis in very preterm infants and an earlier achievement of full nutrition.¹¹

There is no standard oral care protocol in NICUs. Each unit applies oral care at different frequencies and with various methods within its own determined protocol. This study aims to contribute to standardizing oral care practices in NICUs and determine the most effective methods.

Methods/Methodology

Design

This is a two-group, parallel, prospective, and randomized controlled study.

Study setting and sampling

The research population consisted of preterm newborns between 28 and 33 weeks who received treatment with an orogastric tube in the NICU of the Trakya University Faculty of Medicine between 15 January, 2024, and 23 April, 2024. The sample size for the study was calculated using the G*Power 3.1 Program, considering that each group in experimental studies should consist of at least 30 individuals and considering the power of the test. Our study calculated that at least 32 observations in each intervention and control group were needed to achieve a power level of 90% at a significance level of 5% with an effect size of 0.75. Therefore, the sample size for the study was determined to be 64 newborns. The consort flow diagram of the study is shown in Figure 1.

FIG. 1.

Consort flow diagram.

Inclusion and exclusion criteria

Inclusion criteria: •

Being in the NICU

•

Not being intubated or on nasal Contnous Positive Airway Pressure (CPAP) during oral care in the study

•

Being fed through an orogastric tube

•

Being fed with breast milk or a mix of breast milk and formula

•

Not having been orally fed and currently not being fed

•

Being a preterm (28–33 weeks) baby

Exclusion criteria, •

To have started breastfeeding

•

Having a cleft palate or lip

•

Having a neurological, physiological, or cardiac problem that hinders feeding

•

Having a major congenital anomaly

•

Being intubated/CPAP.

Study interventions

Intervention group: Nursing care, including oral care and feeding, was applied to newborns twice a day (in the morning at 09:00 and in the evening at 15:00). The oral assessment scale was scored twice, before the morning oral care and after the evening oral care. Oral care was continued for 10 days using breast milk. For oral care, the baby’s mother’s milk was used. Fresh breast milk was used daily. Two milliliter of breast milk was dropped onto a sterile gauze for each care session, and the cheeks, tongue, and palate were cleaned. The steps of the procedure are as follows: •

Disposable gloves were used after hand hygiene was ensured.

•

If the baby has feeding needs, this is done before oral care.

•

During oral care, the researcher closely observed the mouth, lips, and tongue condition to conduct a comprehensive oral assessment.

•

A gauze pad was moistened with breast milk and gently rotated along the lips.

•

It was also rotated in the oral cavity, around the gum line, and on the tongue. The aim is to cover the cheek cavity with a milk layer.

Control group: Nothing was applied outside of routine clinical practice. In routine practice, oral care is done with distilled water if necessary for the baby’s needs.

Randomization and blinding

The “stratified block randomization” method was used to determine which group of preterm babies to be involved will be assigned to. Stratification is preferred since it ensures that patient characteristics (gestational age, gender, postnatal age, etc.) that could affect study results are evenly distributed among groups. In block randomization, a separate block is generated for each combination of common variables, and subjects are assigned to the appropriate block of common variables. Once all subjects are identified and assigned to blocks, simple randomization is performed within each block to assign subjects to one of the groups. In the present study, stratification was done based on gestational age. Gestational age is planned in two blocks: first group (28–30 weeks of gestational age range) and second group (31–33 weeks of gestational age range). Another researcher carried out the stage of inclusion in the intervention and control groups to prevent study bias through block randomization. In the present study, the data collection was performed by a researcher. Since the population from which the data were collected is babies, the babies who received the intervention do not know which group they are in. Similarly, the mothers of the babies included in the study do not know which group they are in. One of the researchers also analyzed the study data. Therefore, the present study has a single-blinded design.

Instrument with validity and reliability

The “Newborn Oral Health Assessment Tool (NOHAT)” used in this study was developed by Duran and Yıldırım Sarı by considering the clinical patient observations. This tool consists of five items: 1)

Lips and mouth corners (when evaluating tissue appearance, a score of 0–2 is given based on pink-moist, dry-chapped, and ulcer-bleeding condition).

Tongue (with a light source, a score of 0–2 is given by considering the pink-moist-prominent papilla, red-pale-disappeared papilla, and ulcer-rash condition).

Oral cavity/oral mucosa (with a light source, a score of 0–2 is given by considering the pink-moist oral mucosa, red-white spots, and ulcer-rash condition).

Saliva (when observing saliva consistency, a score of 0–2 is given by considering the fluid-clear, increased clear saliva-flowing out of the mouth, and sticky-yellow/green secretion condition).

Swallowing (when observing swallowing, a score of 0–2 is given by considering the no secretion accumulation in the mouth, secretion accumulation in the mouth, and secretion flowing out).

Each item evaluated based on the scale is given a minimum of 0 and a maximum of 2 points. The total score on this scale ranges from a minimum of 0 to a maximum of 10 points. There is no cutoff point for the scale. The Kuder–Richardson 20 value for the NOHAT was found to be 0.750. Given this result, the internal reliability of the tool is high. Item total score correlations also support the reliability of the tool. In line with the results of this study, it was determined that the use of the tool in the newborn patient population is appropriate.¹² Oral care is necessary in routine for tube-fed newborns. Therefore, in tube-fed newborns, an objective oral health assessment tool is used to evaluate the baby’s oral care needs and frequency.

Data collection

The data collection in this study was conducted by using the “Newborn Clinical Characteristics Form” developed by the researchers and consisting of 13 questions describing the clinical characteristics of preterm newborns and the NOHAT” scale developed by Duran and Yıldırım Sarı.¹²

Data analysis

Statistical analyses were conducted using the SPSS 27.0 package program. Continuous data obtained in this study were summarized in terms of mean and standard deviation, while categorical data were summarized in percentage distribution. Parametric and nonparametric tests were used in examining the relationship between dependent and independent variables based on the data type. The Shapiro–Wilk test was used to examine whether the data were normally distributed. Data were summarized in terms of mean, standard deviation, number, and percentage. Mann Whitney U test, continuity correction test, Fisher’s exact test, and independent-samples T test were used to test the homogeneity of categorical variables. For non-normally distributed data, Mann–Whitney U and Wilcoxon signed ranks tests were used in comparing the mean values.

Results

There was no significant difference in the demographic characteristics of the babies between the intervention and control groups (p > 0.05), and it was observed that the groups showed homogeneous distribution (Table 1).

Table 1.

Comparison of Intervention and Control Groups by the Demographic Characteristics of Babies

Variable	Intervention group n (%)/mean (SD) min-max n = 32	Control group n (%)/mean (SD) min-max n = 32	Test value
Gender
Female	15 (46.9)	13 (40.6)	X² = 0.063^**
Male	17 (53.1)	19 (59.4)	p = 0.801
Gestation age	31.68 ± 0.99	31.68 ± 0.99	Z = 0.000^*
	(30–33)	(30–33)	p = 1.000
Birth weight (g)	1670.31 ± 213.390	1673.59 ± 213.05	T = −0.062
	(1080.00–2000.00)	(1320.00–2150.00)	p = 0.951
1’ Apgar score	6.87 ± 1.79	7.78 ± 1.40	Z = −2.138^*
			p = 0.033
5’ Apgar score	8.78 ± 1.03	9.06 ± 0.91	Z = −1.064^*
			p = 0.287
Delivery method
Vaginal delivery	11 (34.4)	12 (37.5)	X² = 0.000^**
Cesarean	21 (65.6)	20 (62.5)	p = 1.000
Mechanical ventilator
Invasive	—	—	X² = 0.344^***
Noninvasive	31 (96.9)	30 (93.8)	p = 0.557
Nothing	1 (3.1)	2 (6.2)
Mechanical ventilator duration			Z = −0.998^*
	2.21 ± 1.66	2.21 ± 2.23	p = 0.318
Number of days on TPN	9.25 ± 4.26	7.34 ± 3.61	Z = −1.782^*
			p = 0.075
The day the intervention started	4.71 ± 3.23	4.81 ± 4.49	Z = −0.588^*
			p = 0.556
The day the intervention ended	13.71 ± 3.23	13.68 ± 4.57	Z = −0.915^*
			p = 0.360
Length of hospital stay	28.18 ± 5.15	30.46 ± 6.08	Z = −1.653^*
			p = 0.098
Discharge weight (g)	2169.21 ± 176.47	2282.81 ± 189.81	Z = −2.479^*
			p = 0.013

Mann–Whitney U test.

Continuity correction test.

***

Fisher’s exact test.

****

Independent-samples T test.

SD, standard deviation.

The comparison of mean daily NOHAT scores of the intervention and control groups before and after the intervention is presented in Table 2.

Table 2.

Comparison of Daily NOHAT Score Averages for Babies

Day	Intervention group mean (SD)	Control group mean (SD)	Test value
1.
Pretest	5.25 ± 1.77	5.96 ± 1.67	Z = −1.864p = 0.062
Posttest	3.96 ± 1.65	5.43 ± 1.89	Z = −3.162p = 0.002
2.
Pretest	3.68 ± 1.74	5.46 ± 1.60	Z = −4.084p < 0.001
Posttest	2.71 ± 1.78	4.46 ± 1.60	Z = −3.993p < 0.001
3.
Pretest	2.71 ± 1.78	4.28 ± 1.46	Z = −3.953p < 0.001
Posttest	1.71 ± 1.78	3.28 ± 1.46	Z = −3.953p < 0.001
4.
Pretest	2.00 ± 1.72	3.28 ± 1.46	Z = −3.806p < 0.001
Posttest	1.00 ± 1.72	2.28 ± 1.46	Z = −3.806p < 0.001
5.
Pretest	0.93 ± 1.60	2.65 ± 1.47	Z = −4.246p < 0.001
Posttest	0.65 ± 1.26	1.56 ± 1.18	Z = −4.160p < 0.001
6.
Pretest	1.31 ± 0.89	2.37 ± 1.33	Z = −4.361p < 0.001
Posttest	0.31 ± 0.89	1.37 ± 1.33	Z = −4.361p < 0.001
7.
Pretest	0.34 ± 0.93	1.93 ± 1.13	Z = −5.375p < 0.001
Posttest	0.25 ± 0.67	0.46 ± 1.10	Z = −0.578p = 0.563
8.
Pretest	0.43 ± 0.71	1.56 ± 1.18	Z = −4.442p < 0.001
Posttest	0.12 ± 0.33	0.81 ± 1.44	Z = −2.215p = 0.027
9.
Pretest	0.87 ± 0.49	1.09 ± 0.99	Z = −0.390p = 0.697
Posttest	0.00 ± 0.00	0.31 ± 0.33	Z = −2.311p = 0.021
10.
Pretest	0.21 ± 0.42	1.09 ± 0.53	Z = −5.556p < 0.001
Posttest	0.00 ± 0.00	0.37 ± 0.49	Z = −3.813p < 0.001

SD, standard deviation; Z, Mann–Whitney U test; NOHAT, Newborn Oral Health Assessment Tool.

There was no significant difference in the mean NOHAT scores between the intervention and control groups on the first-day pretest. However, there was a statistically significant difference in the mean NOHAT scores on the final test (Z = −3.162, p = 0.002). The NOHAT scores of babies who received oral care with breast milk were lower. Daily comparisons showed that there was only a significant difference between the final test on the 7th day (Z = −0.578, p = 0.563) and the pretests on the 9th day (Z = −0.390, p = 0.697). At the same time, all other comparisons had a significant difference (Table 2).

There was a statistically significant difference for all days between the pretest and posttest mean NOHAT scores of the babies in the intervention group. Similarly, comparing the pretest and posttest mean NOHAT scores of the babies in the control group, there was a statistically significant difference for all days (Table 3).

Table 3.

Comparison of Intragroup NOHAT Score Averages for Babies

NOHAT score averages
Day	Intervention group			Control group
Day	Pretest mean	Posttest mean (SD)	p Value	Pretest mean (SD)	Posttest mean (SD)	p Value
1	5.25 ± 1.77	3.96 ± 1.65	<0.001^a	5.96 ± 1.67	5.43 ± 1.89	0.001^a
2	3.68 ± 1.64	2.71 ± 1.78	<0.001^a	5.46 ± 1.60	4.46 ± 1.60	<0.001^a
3	2.71 ± 1.78	1.71 ± 1.78	<0.001^a	4.28 ± 1.46	3.28 ± 1.46	<0.001^a
4	2.00 ± 1.72	1.00 ± 1.72	<0.001^a	3.28 ± 1.46	2.28 ± 1.46	<0.001^a
5	0.93 ± 1.63	0.65 ± 1.26	0.003^a	2.65 ± 1.47	1.56 ± 1.18	<0.001^a
6	1.31 ± 0.89	0.31 ± 0.89	<0.001^a	2.37 ± 1.33	1.37 ± 1.33	<0.001^a
7	0.34 ± 0.93	0.25 ± 0.27	0.083^a	1.93 ± 1.13	0.46 ± 1.10	<0.001^a
8	0.43 ± 0.71	0.12 ± 0.33	0.002^a	1.56 ± 1.18	0.81 ± 1.44	<0.001^a
9	0.87 ± 0.49	0.00 ± 0.00	<0.001^a	1.09 ± 0.99	0.31 ± 0.33	<0.001^a
10	0.21 ± 0.42	0.00 ± 0.00	0.008^a	1.09 ± 0.53	0.37 ± 0.49	<0.001^a

Wilcoxon signed ranks test.

SD, standard deviation; NOHAT, Newborn Oral Health Assessment Tool.

Discussion

Skin permeability is higher in premature babies when compared with term babies, and oral care with breast milk helps protect the oropharyngeal mucosa.¹³^–¹⁵

The present study demonstrates oral mucosal changes in preterm infants with oral care performed using breast milk and sterile distilled water, as stated in the literature. Therefore, this randomized and controlled experimental study was carried out to evaluate the effectiveness of oral care performed with breast milk and sterile distilled water in preterm newborns fed with an orogastric tube. In this study, the mean NOHAT scores of infants who received oral care with breast milk were lower than infants who received oral care with sterile distilled water, and the difference between them was statistically significant. Babies who received oral care with breast milk healed faster. Digal et al. evaluated the oral care performed by babies with their mother’s milk by using the “mouth assessment tool (MAT)” in a study that involved 146 babies. As a result, babies who received oral care with breast milk had lower MAT scores. In the present study, NOHAT scores were lower in the breast milk group.¹⁶ This research is consistent with our findings. In the research conducted by Jain et al. (2022) with a double-blind, randomized controlled design, 110 preterm babies were involved in both groups. In the intervention group, oral care with breast milk was performed every 8 hours, whereas the other group received care with an empty gauze at the same frequency.¹⁷ The research results are consistent with those reported in the present study.

Oral administration of breast milk in preterm newborns effectively cleans the mouth area and affects the immunocompetent cells there.¹⁷ In premature babies, the thinness of the epidermis can lead to disruptions in skin integrity, especially around the mouth and lips, when adhesive tapes are used to secure the orogastric tube. It is essential to maintain the integrity and care of this area. In the randomized controlled study carried out by Özsayın and Cetinkaya (2023), it was shown that the hydrocolloid and silicone tape used to secure the orogastric tube in preterm infants did not damage the mucosal integrity around the mouth and lips, whereas the silk tape was determined to disrupt the skin integrity around the mouth partially. Maintaining the integrity of oral mucosa and the area around the mouth is essential to the oral care routine.¹⁸ In the present study, silk tape (hospital routine) was used to secure the feeding tube in preterm infants fed with an orogastric tube. Therefore, oral care involves the care of the area around the mouth and oral cavity. It is also important to use medical tapes that cause less damage to the mucosa and skin when securing the orogastric tube.

In the Basic Newborn Care guide prepared by the Department of Child and Adolescent Health of the Turkish Public Health Institution, it is stated that sterile saline, boiled and cooled water, or specially developed kits for oral care can be used for mouth care.¹⁹ In contrast to the literature, Ahn et al. (2019) examined the effectiveness of sterile water in oral care. They reported no difference between newborns who received oral care with sterile water and those who did not receive oral care.²⁰ In this study, oral care performed using sterile water was found to be effective but not as effective as breast milk.

Therefore, it is recommended that the use of breast milk in oral care be included in international guidelines prepared for oral care protocols.

Strengths and limitations of the study

The present study has strengths and limitations. First, even though it is based on a small sample, we evaluated the impact of oral care over a long period. Second, this study did not change the routine care in the institution (control group), whereas the intervention group received oral care with breast milk. The use of breast milk is recommended for oral care practices in NICUs due to its ease of use and cost-effectiveness. In addition, it is recommended to include more randomized controlled trials in international guidelines that will be prepared for oral care protocols in order to use breast milk in oral care.

Conclusion

Oral care in premature babies is critical in maintaining the integrity of the oral mucosa, mouth area, and oropharyngeal cavity and reducing the risk of infection by acting as a gastrointestinal barrier. This study compared the effectiveness of oral care with breast milk and sterile distilled water in preterm newborns. The results achieved in this study showed that babies who received oral care with breast milk had lower NOHAT scores and faster healing processes than those with sterile distilled water. Consistent with other studies in the literature, it was observed that oral care with breast milk preserved the oral mucosa in preterm babies. Due to breast milk’s ease of use and cost-effectiveness, its use in oral care practices in NICUs is recommended.

Footnotes

Authors’ Contributions

The research was designed by A.Ç. A.Ç. and R.Z.D. collected the data. A.Ç. and Z.Ç. conducted the analysis and interpreted the findings. A.Ç., Z.Ç., and R.Z.D. prepared the original draft of the article.

Ethical Considerations

Necessary permissions for the research were obtained from a university’s Non-Interventional Clinical Research Ethics Committee (date: 11.09.2023, protocol code: TÜTF-GOBAEK 2023/204). Subsequently, permissions for the implementation of this research were obtained from the hospital where the research will be conducted (number: E-79056779-540551, date: 26.10.2023). Parents were included after obtaining verbal and written consent. The research was conducted following the Helsinki Declaration. The clinical trial registration of the research (ID number: NCT06129266) was done prospectively.

Disclosure Statement

The authors declare that no conflict of interest exists.

Funding Information

The authors did not receive any funding from any institution or organization for this study.

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