Paediatrica Indonesiana p-ISSN 0030-9311.
e-ISSN 2338-476X.
Vol.
No.
DOI: https://doi.
org/10.
14238/pi62.
Original Article Non-nutritive sucking milestones of preterm infants in Indonesia: a descriptive study Luh Karunia Wahyuni1.
Irawan Mangunatmadja2.
Risma Kerina Kaban2.
Elvie Zulka Kautzia Rachmawati3.
Melinda Harini1.
Budiati Laksmitasari1.
Agatha Geraldyne1.
Inez Ayuwibowo Sangwidjojo1.
Dini Prima Utami1.
Victor Prasetyo Poernomo1.
Adrian Prasetya Sudjono1.
Noveria Susita Ginting1 Abstract Background Non-nutritive sucking (NNS) maturity has been used as one of the markers of oral feeding readiness in infants.
Prematurity may hinder the attainment of NNS milestones.
Depending on gestational age (GA) at birth, preterm infants may display various degrees of immaturity, potentially affecting the strength, coordination, and efficiency of skills required for NNS.
Objective To identify the progression of NNS patterns across gestational age groups of preterm infants in Indonesia by comparing NNS parameters between moderate-to-late preterm and very preterm infants.
Methods NNS evaluation was conducted in 120 preterm infants born at 28-34 weeks gestational age in five tertiary hospitals in Jakarta.
Indonesia.
Three aspects of NNS .
uction pressure, number of suctions per burst, and time between burst.
were documented and arranged to present a descriptive overview.
A suction pressure measurement device was used to record, identify, and analyze NNS We hypothesize that maturity, as determined by GA, positively affected the attainment of NNS milestones.
Results Moderate-to-late preterm infants (GA 32 to <37 week.
, compared to very preterm infants (GA 28 to <32 week.
, had higher mean NNS pressure (-79.
8 vs.
7 mmHg, respectively.
P=0.
and shorter mean time between bursts .
63 vs.
36 s, respectively.
P=0.
Mean number of suctions per burst were also significantly different between the two GA groups .
90 vs.
99 sucks/burst, respectively.
P=0.
Conclusion Maturity, as reflected by GA, had a positive effect on the attainment of NNS milestones in preterm infants in Indonesia.
Significant differences in the three NNS parameters: number of suctions per burst, time between bursts, and suction pressure were found between moderate-to-late preterm and very preterm infants.
[Paediatr Indones.
62:311-7.
DOI: https://doi.
org/10.
14238/pi62.
311-7 ].
Keywords: preterm infants.
gestational age.
nonnutritive sucking milestone wo forms of sucking in infants are distinguished into nutritive sucking (NS) and non-nutritive sucking (NNS).
Nutritive sucking is an infantAos primary means to receive nutrition, while NNS is sucking in the absence of nutritional flow, with the aim of self-regulation, fulfilling the natural desire of sucking, and exploration.
2 NNS has been observed to begin as early as 15 weeks after conception during intrauterine life and become stable and well-patterned by 34 weeks gestational age.
3,4 Non-nutritive sucking consists of burst-pause patterns, in which there is a consistent pattern of NNS followed by a rest, and then a return to the pattern.
5 The maturity of NNS has been used as one of the markers of oral feeding readiness in infants.
2,6 All healthy, fullterm infants can perform a stable burst-pause NNS 7,8 Degree of prematurity at birth may hinder the attainment of NNS milestones in the preterm From the Department of Physical Medicine & Rehabilitation1.
Department of Child Health2, and Department of Ear.
Nose, and Throat Clinic3.
Universitas Indonesia Medical School/Dr.
Cipto Mangunkusumo Hospital.
Jakarta.
Indonesia.
Corresponding author: Luh Karunia Wahyuni.
Department of Physical Medicine and Rehabilitation.
Universitas Indonesia Medical School/ Dr.
Cipto Mangunkusumo Hospital.
Jl.
Pangeran Diponegoro No.
Senen.
Jakarta Pusat 10430.
Indonesia.
Email: luhkwahyuni@gmail.
Submitted January 14, 2022.
Accepted October 28, 2022.
Paediatr Indones.
Vol.
No.
September 2022 A 311 Luh Karunia Wahyuni et al.
: Non-nutritive sucking milestones of preterm infants in Indonesia: a descriptive study 9 Depending on their gestational age (GA) at birth, preterm infants may display various degrees of immaturity of their nervous, anatomical, and physiological control systems, potentially affecting the strength, coordination, and efficiency of the skills required for NNS.
9-12 Assisted oral feeding is required for most preterm infants until they are able to achieve full oral feeding ability.
Preterm infants must achieve early feeding milestones described by three aspects of NNS .
uction pressure, number of suctions per burst, and time between burst.
Establishing consistent and well-patterned NNS is critical, because NNS is a precursor to oral feeding development.
Standardized methods to measure NNS have not been established.
A commonly used approach to assess NNS is to place oneAos little finger into the infantAos mouth halfway covering the tongue.
1 However, this approach provides only a subjective and descriptive evaluation, is highly dependent upon the clinicianAos experience and tactile sensitivity, as well as how long the infant sucks on the finger.
14 This study used a suction pressure measurement device to objectively quantify NNS parameters in preterm infants .
umber of suctions per burst, time between bursts, and suction Previous studies have been done to quantify NNS in preterm infants.
5,7,16,17 However, to date.
NNS milestones of preterm infants in Indonesia have not been documented.
Such information is critical, as it can aid health care professionals working with this population to get a better understanding of NNS, since NNS is one of the markers of oral feeding readiness in 13 Hence, we aimed to identify the progression of NNS patterns across gestational age (GA) groups of preterm infants in Indonesia by comparing NNS parameters between moderate-to-late preterm and very preterm infants.
We hypothesized that maturity .
etermined by gestational ag.
would have a positive effect on the attainment of NNS milestones.
Methods This descriptive, cross-sectional study was performed from August to November 2021 in five tertiary hospitals in Jakarta.
Indonesia.
A consecutive sample of 120 preterm infants born between 28-34 weeks of gestation were included.
Exclusion criteria were 312 A Paediatr Indones.
Vol.
No.
September 2022 craniomaxillofacial malformation, neonatal asphyxia with an initial Apgar score of <7, grade 3 and 4 intraventricular hemorrhage (IVH), and the use of an endotracheal tube at the time of assessment.
NNS measurement was performed by general practitioners who had been trained to use a suction pressure measurement device in preterm infants.
Written informed consent was obtained from the infantsAo mothers prior to examination.
This study was approved by the Health Research Ethics Committee of the Universitas Indonesia Medical School.
The suction pressure measurement device was assembled (Figure .
and evaluations were performed according to the method described by Wahyuni et 15 Measurement was carried out for 1 minute with the infant in a quiet-alert state and performed 30 minutes before the infantAos feeding schedule.
Subjects were classified by GA based on the World Health Organization (WHO) sub-category of prematurity.
According to the guideline, our subjects could be classified into two of the three sub-categories, namely very preterm .
to <32 weeks GA) and moderateto-late preterm infants .
to <37 weeks GA).
Since the highest GA in our inclusion criteria was 34 weeks, the cut-off GA for moderate-to-late preterm infants in our study was 34 weeks.
Birth weight (BW) was categorized as follows: extremely low birth weight (ELBW) when BW was <1,000g, very low birth weight (VLBW) when BW was <1,000-1,499g, and low birth weight (LBW) when BW was 1,500 to <2,500g.
Collected data were analyzed using Microsoft Excel software (Microsoft Inc.
Redmond.
Washingto.
The NNS parameters examined were: .
number of suctions per burst, .
time between bursts, and .
suction pressure.
A burst was defined as the period of sucking between pauses, with one burst consisting of several suctions.
Time between bursts is the sucking rest period (Figure .
Suction pressure was the strength and compression of the tongue against the palate as well as the ability to form intraoral pressure.
20 The NNS ability was interpreted as adequate if the infant was able to perform a strong and rhythmic NNS characterized by an average of 5-10 suctions/burst, an average time between bursts of 4-9 seconds, and an average suction pressure of -16.
7 to -87mmHg.
2,21,22 Figure 2 illustrates a graph of suction pressure measurement results.
In the first burst, 19 Luh Karunia Wahyuni et al.
: Non-nutritive sucking milestones of preterm infants in Indonesia: a descriptive study Figure 1.
Assembly steps of sucking mechanism evaluation system tool: 1.
The amplifier cable is connected to the adapter.
The other side of the same cable is connected to the amplifier, connecting the wires following the pattern on the amplifier.
The data logger adapter cable is connected to the data logger.
The black and red wires attached to the data logger are connected to the amplifier according to the color of the Press the on button.
The sucking sensor cable is connected to the amplifier according to the pattern on the amplifier.
The sucking sensor cover is opened and connected to the pacifier.
Gain on the amplifier is adjusted at 100.
Connect all tools to mains.
The data logger is calibrated by adjusting the amplifier using a screwdriver (-).
The magnitude of the voltage is adjusted at 0.
Figure 2.
Suction pressure measurement results graph.
The blue bar represents bursts, the yellow bar represents time between bursts, and the orange line represents suctions.
suctions were recorded, as shown by the number of peaks on the graph (Figure .
The infant's suction pressure was determined by the average amplitude of the graph peaks in the bursts.
Sucking pressure was presented in negative values to correspond to the negative sucking pressure.
All data were saved under participantsAo ID numbers in an effort to avoid researcher bias during data analysis.
Data analysis was performed using SPSS for Mac version 20.
0 software (IBM.
Armonk.
New Yor.
Descriptive analysis was performed for all the We compared gender and birth weight distribution in the two GA groups .
ery preterm and moderate-to-late preter.
Independent t-test was used to analyze differences in characteristics of NNS parameters .
uction pressure, number of suctions per burst, and time between burst.
between the two GA A P value of <0.
05 was considered statistically significant, and we incorporated 95% confidence Paediatr Indones.
Vol.
No.
September 2022 A 313 Luh Karunia Wahyuni et al.
: Non-nutritive sucking milestones of preterm infants in Indonesia: a descriptive study Figure 3.
Burst description of the suction pressure measurement device.
The X-axis represents time in milliseconds .
the Y-axis represents amplitude in mmHg.
In this burst, 19 suctions were recorded, as shown by the number of peaks on the graph.
Results Subjects were 120 preterm infants classified into either the moderate-to-late preterm .
or very preterm .
Characteristics of subjects are described in Table 1.
The very preterm group had more females than males .
16, respectivel.
, while the moderate-to-late preterm group had more males than females .
34, respectivel.
Out of five ELBW infants, four were categorized as very preterm, and one was in the moderate-to-late preterm group.
Among VLBW infants, the number of very preterm infants was higher compared to the number of moderate-to-late preterm infants .
16, respectivel.
On the other hand, the number of LBW infants was higher in the moderate-to-late preterm group than in the very preterm group .
14, respectivel.
Parameters of NNS .
uction pressure, number of suctions per burst, and time between burst.
were expressed as mean and standard deviation (SD).
Mean suction pressure was higher in moderate-to-late preterm infants [-79.
8 (SD 31.
compared to very preterm infants [-72.
7 (SD 31.
(P=0.
However, no significant difference was found in the number of suctions per burst between very preterm infants .
99 (SD 2.
compared to moderate-to-late preterm infants .
Table 1.
Characteristics of subjects Gestational age Characteristics Gender, n (%) Male Female Birth weight (BW), n (%) Extremely low BW .
Very low BW .
Low BW.
Very preterm .
- < 32 week.
Moderate-to-late preterm .
- < 37 week.
P value <0.
314 A Paediatr Indones.
Vol.
No.
September 2022 Luh Karunia Wahyuni et al.
: Non-nutritive sucking milestones of preterm infants in Indonesia: a descriptive study (SD 2.
(P=0.
Moderate-to-late preterm infants had shorter time between bursts .
(SD 1.
than very preterm infants .
(SD 2.
(P=0.
(Table .
Discussion Maturity of NNS reflects central nervous system integrity and has been used as a marker of oral feeding readiness and orofacial motor development in preterm 23,24 Non-nutritive sucking is a precursor skill to oral feeding.
however, oral feeding skills are far more complex as it requires the coordination between sucking, swallowing, and breathing.
22 Although NNS ability is not necessarily predictive of feeding success, stable cardiorespiratory function .
reathing pattern, oxygen saturatio.
during NNS may indicate the infant's ability to manage oral feeding and represent hunger cues.
25 Quantitative measures of the NNS pattern can provide information related to the preterm infants' developmental status and progression of oromotor control systems.
26 It is often assumed that infants possess the skills necessary to feed by 34 weeks GA and will be able to maintain feeding before 37 weeks GA.
However, to date, only a few studies have systematically investigated the age at which preterm infants attain essential early feeding milestones, or the factors that influence this important aspect of neonatal development.
In our study, preterm infants in both gestational age groups demonstrated strong and rhythmic NNS pattern, characterized by an average of 5-10 suctions/ burst, an average of 4-9 seconds of time between bursts, and an average suction pressure of -16.
7 to -87 mmHg.
These objective NNS characteristics represent the NNS ability in infants aged 32-36 weeks post-menstrual age.
2,21,22 However, moderate-to-late preterm infants showed higher NNS pressure, shorter time between bursts, and slightly higher number of suctions per burst compared to very preterm infants (Table .
With increased maturation, we saw a significant gradual change towards a more intense sucking pressure (P=0.
and shorter intervals (P=0.
Previous studies of NNS measurement in preterm infants have been reported.
5,16,21,22 Measurements showed improved sucking ability with maturation and age, and consistent sucking ability by 32-34 weeks post-menstrual age.
25 Medoff-Cooper found longer sucking episodes or bursts as infants mature.
Hafstrym and Kjellmer have also shown a more stable rhythm, faster pace and more intense sucking activity with longer bursts and shorter intervals with increased 5 These studies were consistent with our A more stable rhythm of NNS is associated with maturity of general cerebral development as synaptogenesis and myelinization increase.
There were several limitations that must be acknowledged in this study.
First, infants may already have previous NNS experience on pacifiers prior the start of this study, and the exact amount has not been Therefore, future studies should control for prior pacifier use.
Another limitation of this study was the small sample size and the study being conducted only in Jakarta, thus the results may not have been representative of other areas in Indonesia.
Furthermore, suction pressure measurement devices are currently very limited in availability even in the capital region of Jakarta, and has not been widely used in Indonesia.
In conclusion, this study showed that maturity, as represented by GA, had a positive effect on the attainment of NNS milestones in preterm infants in Indonesia.
Significant differences of the three NNS parameters of number of suctions per burst, time between bursts, and suction pressure were found between very preterm and moderate-to-late preterm Table 2.
Gestational age and NNS parameters Variables Very preterm .
Moderate-to-late preterm .
P value Mean suction pressure (SD), mmHg 7 .
Mean number of suctions /burst (SD) 99 .
Mean time between bursts (SD), sec 36 .
*P<0.
Paediatr Indones.
Vol.
No.
September 2022 A 315 Luh Karunia Wahyuni et al.
: Non-nutritive sucking milestones of preterm infants in Indonesia: a descriptive study Further studies with larger sample size are needed in order to document NNS milestones across GA groups, from very late to full-term.
Conflict of interest None declared.
Funding acknowledgment The authors received no specific grants from any funding agency in the public, commercial, or not-for-profit sectors.
References