LATCH Scores and Milk Intake in Preterm and Term Infants: A Prospective Comparative Study

Abstract

Objectives:

We aimed to detect the breastmilk intake in preterm and term infants and to determine if the LATCH scoring system (latch; audible swallowing; type of nipple; comfort [breast/nipple]; hold [positioning]) could be helpful to denote that infants have taken enough breastmilk according to their postnatal age and weight.

Materials and Methods:

Sixty-six breastfeeding sessions were monitored and scored simultaneously by using the LATCH scoring system. The weight of the 66 infants (33 preterm, 33 term) was measured before and after a breastfeeding session, and thereby milk intake by breastfeeding was determined. The expected amount of milk volume that infants should receive for each feeding session was calculated according to the postnatal age and weight. The breastmilk intake by breastfeeding was compared with LATCH scores and the expected milk volume for each feeding.

Results:

We observed that 25 term infants (75.8%) took 100% of the expected milk volume for each feeding session, compared with two preterm infants (2.1%) (p=0.009). The median LATCH scores were 7.0 (minimum–maximum=5–9) in preterm babies and 9 (minimum–maximum=7–10) in term babies (p<0.0001). Term babies could consume 95.4% of the expected milk volume for each feeding session, whereas this ratio was only 45% in preterm babies. In each group, babies receiving a score of ≥7 took at least 50% of the expected milk volume for each feeding session. In each group, higher LATCH scores were associated with higher median intake, but the minimum and maximum intake for each LATCH score revealed marked variability.

Conclusions:

High LATCH scores (7–10) may be helpful to determine that infants take at least 50% of the expected breastmilk volume for each feeding in both preterm and term infants. However, LATCH scores cannot substitute for test weights in premature infants because of variability in minimum and maximum milk intake per LATCH score.

Introduction

Previous studies have shown that breastfeeding can be initiated when the infant is physiologically stable and reach sufficient maturity, irrespective of gestational age (GA) or gestational weight.¹ Compared with full-term neonates, preterm infants generally need a period of full gavage feeding because of an immature and disorganized sucking pattern and then initiate oral feeding between 32 and 35 weeks of age.^2,3 Nonetheles, it is not clear when preterm infants can be breastfed exclusively. Nursing mothers who have preterm or term babies are concerned about the amount of milk that their infant is receiving and are not sure whether it is sufficient to promote growth.⁴ Furthermore, healthcare staff need objective methods to evaluate breastfeeding effectiveness before discharging babies.

For this purpose, several breastfeeding assessment tools have been developed.^5–7 None of these tools has been used in preterm babies and measured against how much milk the infant did in fact consumed. The most widely used method to measure the amount of milk consumed is test-weighing, in which the infant is weighed before and after feeding.^1,8,9 The weighing-test procedure provides an extremely accurate measure of milk intake in both preterm and term babies,^10–14 whereas some authors put forward that it is stressful for the mothers and that it is not beneficial for maternal role development or mother–infant interaction.^9,15 We aimed to investigate the benefit of the LATCH scoring system (latch; audible swallowing; type of nipple; comfort [breast/nipple]; hold [positioning]), which is easy to use, as to whether it could be useful to measure the amount of milk intake in both preterm and term infants. Taking this fact into account, we tried to integrate the information from both LATCH scores and test weighing.

The primary outcome of this study was to detect the breastmilk intake in preterm and term infants, and the secondary outcome was to determine if the LATCH scoring system could be helpful to determine whether infants were taking enough breastmilk according to their postnatal age and weight.

Materials and Methods

This prospective study was conducted in the neonatal intensive care unit of a tertiary hospital between August and December 2013. The research was approved by the local ethics committee, and informed consent was obtained from the legal caregiver of each child before enrollment. Preterm (GA=34–37 weeks, or GA <34 weeks and corrected GA=34–37 weeks) and term (GA >37 weeks) infants who had been admitted to the neonatal intensive care unit for any reason were enrolled in the study. The babies had to be fed via oral intake completely (exclusively or complementary breastfeeding), and mothers had to have enough milk for breastfeeding to be eligible for the study. Both of the mother's breasts were expressed by an electric pump to evaluate whether they had enough milk volume that the baby would need for each breastfeeding. Expressed milk volume was assessed by a nurse (RN 1).

Mothers who did not have enough milk for each feeding or who had nipple problems (plain or inverted nipple) and infants who had a congenital abnormality that prevent sucking were excluded from the study. Blood samples were taken to analyze the hemoglobin levels in order to exclude anemia.

The expected milk volume that infants should take for each feeding session within 3-hour intervals was calculated according to the postnatal age and weight (60 mL/kg for the first postnatal day, increased by 10 mL/kg for each day and reaching 150 mL/kg/day on postnatal Day 10 and thereafter in term infants; 70 mL/kg for the first postnatal day, increased by 10 mL/kg for each day and reaching 160 mL/kg/day on postnatal Day 10 in preterm infants). After Day 10, the milk volume was able to provide a daily weight gain of 20–30 g in preterm babies (160–200 mL/kg/day). Each infant who had not breastfed within the preceding 3 hours was assessed only one time and by only one nurse. Mother–baby dyads eligible for the study were examined during each breastfeeding session (40 minutes for all infants) at any feeding time suitable to the mother and the nurses.

Before feeding, each infant was weighed on an electronic scale by a nurse (RN 2). Then, infants were breastfed by their mothers. Another nurse (RN 3) assessed breastfeeding sessions by the LATCH scoring system. After feeding, another nurse (RN 4) weighed each infant on the same electronic scale. RN 2 was blinded to the LATCH scores and postfeeding test-weighing, RN 3 was blinded to the pre- and postfeeding test-weighing, and RN 4 was blinded to the LATCH scores and prefeeding test-weighing. Infants were weighed before and after breastfeeding with the same articles of clothing. One gram of weight gain represented 1 mL of milk intake uncorrected for insensible water loss (1 g=1 mL). Breastmilk intake determined with test-weighing was compared with the expected milk volume that the baby should take in each feeding and with LATCH scores.

Instruments

The LATCH breastfeeding assessment tool was developed by Jensen et al.⁵ in 1994 to assist healthcare professionals in evaluating the breastfeeding techniques of mother/infant dyads validity. The tool provides a systematic documentation and standardization with an algorithm, as each letter in the acronym describes a different area of assessment: L describes the ability of the infant to latch onto the breast, A describes audible swallowing noted at the breast, T describes the type of the nipples, C describes the comfort level of the mother regarding her breasts, and H measures the amount of help the mother requires to position her baby at the breast. A numerical score (0, 1, or 2) is assigned to each measure for a possible total score of 10.

Test-weighing

Test-weighing is used to measure how much breastmilk has been consumed by the infant from his or her mother's breast during a feeding session. For test-weighing, a digital electronic infant weight scale is used that shows weight in grams. The scale has to be on a flat surface. The baby is weighed twice: right before and right after a feeding session, with the same clothes on. The diaper or any clothes is not changed until after the baby has been weighed the second time after feeding. The first, lower, weight is subtracted from the second, higher, weight. The difference between these two weights is the amount of milk the baby received. One gram of weight is equal to 1 mL or 1 cm³ of milk.

Statistical analysis

Statistical analysis was performed using SPSS version 15 software (SPSS, Inc., Chicago, IL). The normality of continuous variables was investigated by the Shapiro–Wilk test. Descriptive statistics were presented using mean and SD for normally distributed variables and median (and minimum–maximum) for non-normally distributed variables. For comparison of two normally distributed groups, Student's t test was used. Nonparametric statistical methods were used for values with skewed distribution. For comparison of two non-normally distributed groups, the Mann–Whitney U test was used. The χ² test was used for categorical variables and expressed as observation counts (and percentages). Statistical significance was accepted when the two-sided p value was <0.05.

Results

Seventy-one patients hospitalized for any reason between August and December 2013 were eligible for the study after the treatment. Five mothers rejected participating to the study, which resulted in 66 mother–baby dyads. Clinical features of the infants (33 preterm and 33 term infants) and results are given in Table 1. Although all mothers had enough milk for their babies, the exclusive breastfeeding ratio was 18.2% (n=6) among preterm infants and 51.5% (n=17) among term infants (Table 1). There was no significant difference in breastmilk volume of preterm and term babies' mothers (Table 1). Twenty-five term infants (75.8%) received 100% of the expected milk volume that they should take in each feeding session according to postnatal age and weight. This ratio in the preterm babies was only 2.1% (n=2), and the difference was significant (Table 1). Term babies received 95.4% of the expected milk volume that they should take in each breastfeeding, whereas preterm babies could receive only 45% (Table 1). The difference between the groups was statistically significant.

Table 1.

General Characteristics of the Study Population and Results

	GA <37 weeks (n=33)	GA ≥37 weeks (n=33)	p
Gestational week [median (minimum–maximum)]	33 (28–35.6)	38 (37–42)	<0.0001^a
Birth weight (g) (mean±SD)	1,984±450	3,227±513	<0.0001^b
Actual weight (g) [median (minimum–maximum)]	2,150 (1,660–3,380)	3,580 (2,170–5,190)	<0.0001^a
Gender [n (%)]			0.80^c
Male	18 (54.5%)	19 (57.6%)
Female	15 (45.5%)	14 (42.4%)
Delivery type [n (%)]			0.001^c
NSVD	10 (30.3%)	23 (69.7%)
C/D	23 (69.7%)	10 (30.3%)
Postnatal day [median (minimum–maximum)	17 (4–45)	9 (4–28)	0.059^a
Exclusive breastfeeding [n (%)]	6 (18.2%)	17 (51.5%)	0.004^a
Hemoglobin (g/dL) (mean±SD)	14.47±3.11	16.36±3.06	0.016^b
Milk intake (mL) [median (minimum–maximum)]	15 (2.5–60)	65 (15–50)	<0.001^a
Percentage of milk intake according to calculated milk volume (mL) [median (minimum–maximum)]	45 (5–100)	95.4 (50–100)	<0.001^a
Babies who consumed 100% of calculated milk volume [n (%)]	2 (6.1%)	25 (75.8%)	0.009^c
LATCH scores [median (minimum–maximum)]	7 (5–9)	9 (7–10)	<0.001^a
Mothers' milk volume by pump (mL) [median (minimum–maximum)]	90 (25–200)	100 (40–150)	0.133^a

By Mann–Whitney U test.

By Student's t test.

By χ² test.

C/D, Cesarean delivery; GA, gestational age; NSVD, normal spontaneous vaginal delivery.

LATCH scores of 60.6% of the preterm babies were 7 and higher; however, this rate was 100% for term babies (Table 2). Preterm and term babies with higher LATCH scores took more breastmilk. In each group, higher LATCH scores were associated with higher median intake (Table 3 and Fig. 1), but the minimum and maximum intake for each LATCH score revealed marked variability. This variability was more pronounced in the preterm group.

FIG. 1.

Preterm and term babies with higher LATCH scores consume more breastmilk.

Table 2.

LATCH Scores of Term and Preterm Infants

LATCH score	GA <37 weeks	GA ≥37 weeks
5	4 (12.1)	0
6	9 (27.3)	0
7	14 (42.4)	2 (6.1)
8	1 (3)	3 (9.1)
9	5 (15.2)	14 (42.4)
10	0	14 (100)
Total	33 (100)	33 (100)
7+	20 (60.6)	33 (100)

Data are number (%).

GA, gestational age.

Table 3.

Milk Intake According to LATCH Scores

	Milk intake (mL)
LATCH score	GA <37 weeks	GA ≥37 weeks	Total
5	10 (5–20) (n=4)	0	10 (5–20) (n=4)
6	10 (2.5–15) (n=9)	0	10 (2.5–15) (n=9)
7	20 (5–45) (n=14)	22.5 (15–30) (n=2)	20 (5–45) (n=16)
8	20 (20–20) (n=1)	35 (25–45) (n=3)	30 (20–45) (n=4)
9	35 (15–60) (n=5)	70 (30–115) (n=14)	60 (15–115) (n=19)
10	0	75 (35–150) (n=14)	75 (35–150) (n=14)
Total	15 (2.5–60) (n=33)	65 (15–150) (n=33)	35 (2.5–150) (n=66)

Data are median (minimum–maximum).

GA, gestational age.

Likewise, both term and preterm babies' percentage of milk intake volume according to expected milk volume increased correspondingly with the LATCH scores (Table 4 and Fig. 2). In both groups, the range of minimum and maximum percentages for each LATCH score was very wide. In both groups (term and preterm) of babies, an increase of LATCH scores provides a higher percentage of babies whose percentage of milk intake volume was at least 50% (Fig. 3).

FIG. 2.

Percentages of breastmilk intake by term and preterm babies according to expected milk volume correlated with the LATCH scores.

FIG. 3.

In both term and preterm babies, an increase in LATCH score suggests a higher rate of success in breastfeeding.

Table 4.

Percentages of Milk Intake According to LATCH Scores

LATCH score	GA <37 weeks	GA ≥37 weeks
5	22.9% (11.1–45%) (n=4)	0
6	22.2% (5–60%) (n=9)	0
7	66.7% (11.1–100%) (n=14)	72.5% (50–95%) (n=2)
8	57.1% (57.1–57.1%) (n=1)	100% (87.5–100%) (n=3)
9	87.5% (33.3–100%) (n=5)	100% (70–100%) (n=14)
10	0	100% (83.3–100%) (n=14)
Total	45% (5–100%) (n=33)	100% (50–100%) (n=33)

Data are median (minimum–maximum).

GA, gestational age.

We have observed that 93.8% of preterm babies and 100% of term babies with LATCH score of 7 and higher received more than 50% of the expected milk volume according to postnatal age and weight.

Discussion

The LATCH scoring system is a good breastfeeding assessment tool as it is short and easy to use; however, there are conflicting data regarding its reliability and validity.^16,17 In our previous study, we have demonstrated that this tool is a valid and reliable option for term infants.¹⁸ To our knowledge, the LATCH scoring system has not been used to assess milk intake of babies. The most commonly used method to measure breastfeeding volume is test-weighing, in which babies are weighed before and after feeding.^1,8–14 In the present study, we have used LATCH scoring in both preterm and term babies and also compared the total scores with milk intake determined by test-weighing. Milk intake and LATCH scores were found to be lower in preterm babies. Both term and preterm babies' percentage of milk intake volume according to expected milk volume increases correspondingly with the LATCH scores. In our study, 93.8% of preterm babies and 100% of term babies with a LATCH score of 7 and higher received more than 50% of milk intake volume according to calculated milk volume. As there was not an equal number of babies in each score subgroup, breastmilk intake for each score cannot be determined. However, we can say that babies with a LATCH score of 7 or higher can suckle at least 50% of the expected volume of milk for each feeding session. Although the LATCH score is associated with higher median milk intake, variability in the minimum and maximum values per LATCH score illustrates its limitations for practice and research. LATCH scores cannot substitute for test weights in premature infants for whom volume of intake must be known to safely management hydration, nutrition, and growth.

Previous studies have shown that audible swallowing surface is significant indicator for the amount of breastmilk that babies have consumed at any breastfeeding session.^19–21 The LATCH tool also includes audible swallowing as one of five breastfeeding indicators. In our study, the assessment was made by taking the total scores into account, but audible swallowing was not measured as a separate indicator. Although it was believed that swallowing was a difficult parameter to measure, previous studies have shown that mothers could examine the swallowing during a feeding session.²² In our study, the mother–baby dyads were evaluated by experienced nurses so there was no problem in the assessment of audible swallowing.

A series of studies have reported that preterm infants do not consume all the available milk from the breast, but instead fall asleep early during feeding, suggesting satiety.^22,23 The clinical indices of intake did not provide an accurate estimation of volume consumed in this population^8,24,25; however, mothers responded to this situation by offering extra milk as a complement (extra milk offered immediately following a breastfeeding episode) or supplements as a replacement. In this study we showed that preterm babies could receive only 45% of the calculated milk volume that they should have taken in each feeding according to postnatal age and weight. Two preterm infants (2.1%) received 100% of the calculated milk volume that they should take in each feeding according to postnatal age and weight. We found that preterm babies should be supported by extra milk as complements or supplements after breastfeeding. These results showed that preterm babies' mothers who thought that their babies were not getting enough milk by breastfeeding and wanted to give extra milk/supplements to them with a bottle or spoon were right in their attitude.

As a result, even if mothers have enough milk for their babies, the rate of exclusive breastfeeding decreases. Although more than half (56%) of the mothers in the study of Piper²⁶ planned to breastfeed exclusively following discharge, only four (9%) achieved this goal at 2 weeks, with a decrease to 5% at 10 weeks postdischarge. In this study, preterm babies had also a low percentage of exclusive breastfeeding (18.2%), as we expected. Although almost all of the term infants could receive enough milk from the breast, exclusive breastfeeding was only 51.2% in these term infants. These results showed that mothers of term infants gave additional nutrients to their babies with unnecessary anxiety.

Conclusions

Preterm babies were not able to suckle all of the expected amount of breastmilk for each feeding session from their mother's breast. LATCH scores greater than (or equal to) to 7 can predict that the baby can take in more than 50% of the expected milk volume for each feeding among both preterm and term infants. LATCH scores cannot substitute for test weights in premature infants, for whom the volume of intake must be known to safely manage hydration, nutrition, and growth, because of variability in minimum and maximum milk intake per LATCH score.

Footnotes

Acknowledgments

We thank the nurses Filiz Polat, Naciye Alkan, and Ebru Ozcan for their valuable contribution to our study.

Disclosure Statement

No competing financial interests exist.

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