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Breast Pump Suction Patterns that Mimic the Human Infant during Breastfeeding: Greater Milk Output in Less Time Spent Pumping For Breast Pump-Dependent Mothers with Premature infants

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  • Rush University, Chicago, IL, USA

Abstract and Figures

The objective of this study was to compare the effectiveness, efficiency, comfort and convenience of newly designed breast pump suction patterns (BPSPs) that mimic sucking patterns of the breastfeeding human infant during the initiation and maintenance of lactation. In total, 105 mothers of premature infants ≤34 weeks of gestation were randomly assigned to 1 of 3 groups within 24 h post-birth. Each group tested two BPSPs; an initiation BPSP was used until the onset of lactogenesis II (OOL-II) and a maintenance BPSP was used thereafter. Mothers who used the experimental initiation and the standard 2.0 maintenance BPSPs (EXP-STD group) demonstrated significantly greater daily and cumulative milk output, and greater milk output per minute spent pumping. BPSPs that mimic the unique sucking patterns used by healthy-term breastfeeding infants during the initiation and maintenance of lactation are more effective, efficient, comfortable and convenient than other BPSPs.
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ORIGINAL ARTICLE
Breast pump suction patterns that mimic the human infant
during breastfeeding: greater milk output in less time
spent pumping for breast pump-dependent mothers with
premature infants
PP Meier
1,2,3
, JL Engstrom
1,4
, JE Janes
3
, BJ Jegier
1
and F Loera
1
1
Department of Women, Children and Family Nursing, Rush University Medical Center, Chicago, IL, USA;
2
Department of
Pediatrics, Rush University Medical Center, Chicago, IL, USA;
3
Department of Women and Children’s Nursing, Rush University
Medical Center, Chicago, IL, USA;
4
Frontier School of Midwifery and Family Nursing, Hyden, KY, USA
Objective: The objective of this study was to compare the effectiveness,
efficiency, comfort and convenience of newly designed breast pump suction
patterns (BPSPs) that mimic sucking patterns of the breastfeeding human
infant during the initiation and maintenance of lactation.
Study Design: In total, 105 mothers of premature infants p34 weeks of
gestation were randomly assigned to 1 of 3 groups within 24h post-birth.
Each group tested two BPSPs; an initiation BPSP was used until the onset
of lactogenesis II (OOL-II) and a maintenance BPSP was used thereafter.
Result: Mothers who used the experimental initiation and the standard
2.0 maintenance BPSPs (EXP-STD group) demonstrated significantly
greater daily and cumulative milk output, and greater milk output per
minute spent pumping.
Conclusion: BPSPs that mimic the unique sucking patterns used by
healthy-term breastfeeding infants during the initiation and maintenance
of lactation are more effective, efficient, comfortable and convenient than
other BPSPs.
Journal of Perinatology advance online publication, 4 August 2011;
doi:10.1038/jp.2011.64
Keywords: lactation; premature infants; breast pump-dependent
women; breast pump suction patterns; human milk feedings
Introduction
Human milk from the infant’s own mother reduces the risk of
costly and handicapping morbidities in premature infants in a
dose-response manner, with higher doses of human milk providing
the greatest protection.
1,2
High doses of human milk are especially
important during the first 28 days post-birth when feedings are
introduced and advanced.
2,3
However, mothers of premature infants
are dependent on a breast pump for the initiation and
maintenance of lactation, and many of these women experience
problems with providing sufficient amounts of milk during this
time.
2,4,5
Despite the frequency of this problem, very few studies
have examined features of breast pumps or breast pump suction
patterns (BPSPs) in this population.
6
This lack of research is
especially concerning because mothers of premature infants are
often breast pump-dependent for weeks or months before their
infants can feed at breast and pumping is no longer necessary.
In mothers of healthy-term infants, effective sucking and milk
removal by the infant have a major role in regulating milk
volume.
7–11
Thus, it seems logical that BPSPs for mothers of
premature infants should mimic the sucking rates (number of
sucks per minute) and rhythms (organization of burstpause
patterning) used by healthy-term infants during the initiation
and maintenance of lactation. One BPSP (Standard 2.0; Medela,
McHenry, IL, USA) has been developed based on extensive research
of sucking patterns of infants during established breastfeeding
(e.g., after the completion of lactogenesis II).
12,13
This BPSP has
two phases, based on sucking patterns used by breastfeeding infants
during a single feeding. The first (stimulation) phase mimics the
rapid sucking rate used by the infant before milk ejection, whereas
the second (expression) phase simulates the slower sucking rate
that occurs after milk ejection.
14
This two-phase BPSP was also
demonstrated to be effective, efficient, comfortable and convenient
in a randomized clinical trial of breast pump-dependent mothers
of premature infants who had initiated lactation and established
an adequate milk volume.
6
However, in the first days post-birth, the healthy-term infant
does not suck in a biphasic pattern, because only minimal
amounts of milk are available for removal before the onset of
lactogenesis II.
15,16
The infant responds to the limited availability
Received 26 September 2010; revised 16 March 2011; accepted 27 March 2011
Correspondence: Dr PP Meier, Department of Women, Children and Family Nursing, Rush
University Medical Center, Chicago, IL 60612, USA.
E-mail: Paula_Meier@rush.edu
Journal of Perinatology (2011),18
r
2011 Nature America, Inc. All rights reserved. 0743-8346/11
www.nature.com/jp
and slow flow of milk with a rapid sucking rate and an irregular
sucking rhythm,
14,17– 19
however, no previous BPSP has attempted
to simulate this unique sucking pattern. We hypothesized that this
early ‘initiation’ sucking pattern does more than just ‘get the milk
out’, and that its intense application to the mammary gland in the
early days post-birth may have a role in programming the
initiation and maintenance of an adequate milk volume. The
purpose of this study was to compare the effectiveness, efficiency,
comfort and convenience of new combinations of BPSPs designed
to mimic the sucking patterns used by healthy-term infants to
initiate and maintain lactation.
Methods
Design
Development of BPSPs. We sought to design BPSPs for breast
pump-dependent mothers that mimic those used by the healthy-
term infant during the initiation and maintenance of lactation.
Thus, the BPSPs that were compared in this study were developed
based upon classic research in the physiology of lactation as well as
the physiology of non-nutritive and nutritive infant sucking. This
research demonstrates that the healthy human infant adapts the
sucking rate, rhythm and pressure to the milk flow rate.
14,18,19
Specifically, during non-nutritive sucking or when milk flows
slowly, the infant sucks rapidly, because little or no milk is
extracted. Thus, the swallow-induced airway closure is infrequent
and breathing is minimally affected.
14,18
However, as the milk flow
rate increases, the infant must swallow the extracted milk and
regulate the closure and re-opening of the airway to integrate
swallowing and breathing.
14,18
As a result, the sucking rate slows
considerably.
14,17– 19
Thus, during established lactation, a
breastfeeding infant sucks rapidly before milk ejection and more
slowly after milk ejection because of the extra time required for
swallowing and breathing once milk begins to flow regularly.
14,18
The standard BPSP. This two-phase BPSP (Standard 2.0,
Medela) consists of an initial (2-min) stimulation phase of rapid
suction events (120 per minute) that correspond to sucking at the
breast before milk ejection under low milk flow conditions. At the
end of 2 min (or sooner if overridden by the breast pump user),
this rate slows to approximately 60 events per minute to mimic
nutritive sucking with regular milk flow. Both the stimulation and
expression phases of the standard BPSP cycle continuously with no
pause events. The standard BPSP was developed before its use in
this investigation, and involved an exhaustive study of its
effectiveness, efficiency, comfort and convenience in healthy-term
infants of mothers with an established milk supply.
12,20,21
Similarly, a previously published randomized clinical trial
demonstrated that it was effective, efficient, comfortable and
convenient in breast pump-dependent mothers of premature
infants with an adequate milk supply.
6
The experimental initiation BPSP. This new BPSP (Preemie þ,
Medela) was designed to mimic the rapid sucking rate and
irregular sucking rhythm used by healthy-term infants during
breastfeeding before the onset of lactogenesis II,
17– 19
when only
small amounts of milk are available for removal.
15
The new
initiation BPSP included periods that mimic non-nutritive sucking
(120 sucks per minute), low milk flow rate sucking (90 sucks per
second) and average nutritive milk flow rate (60 sucks per second)
sucking.
19
These varying sucking rates and rhythms were
interspersed with brief, unpredictable pauses in suction similar to
those that occur during breastfeeding before the OOL-II.
The experimental maintenance BPSP. This new BPSP began
with a 2-minute stimulation phase identical to the current
Standard 2.0 (standard; STD) BPSP. However, the expression phase
of this pattern incorporated a different suction curve in which the
rate varied (3554 cycles per minute) as a function of the amount
of vacuum selected by the mother. The nadir of this vacuum curve
was reached more quickly than with the STD BPSP, mimicking the
sucking rate and rhythm of a ‘hungry’ breastfeeding infant during
conditions of rapid milk flow such as that which occurs
immediately following milk ejection in mothers with an established
milk supply.
14
When the milk flow rate is rapid, infants exert less
suction pressure and suck more slowly to swallow large boluses of
milk and to reopen the airway to breathe.
14,18
These sucking
characteristics of infants were programmed into the expression
phase of the experimental maintenance BPSP.
The experimental initiation and the new maintenance BPSPs
were developed and field-tested over the course of 18 months by
having breast pump-dependent mothers of premature infants
systematically evaluate evolving versions of the BPSPs. This process
was supervised by lactation research nurses and an engineer with
expertise in BPSP programming. Suction pressures, rates, rhythms
and other pumping characteristics were adjusted and evaluated
until mothers consistently reported that the new BPSPs were
effective, efficient, comfortable and convenient.
Research design. A randomized clinical trial design was used to
compare the effectiveness, efficiency, comfort, and convenience of
the new initiation and maintenance BPSPs with the standard BPSP
in the Symphony breast pump in breast pump-dependent mothers
of premature infants. A randomized block design was used to
assure a representative sample of mothers with infants <27 and
X27 weeks’ gestation in each study group to reduce the potential
that the degree of prematurity affected lactation outcomes.
4,22
The
randomized block design also ensured that within every block of
three infants, one infant was randomly assigned to each group so
that environmental and clinical conditions within the neonatal
intensive care unit were consistent among the groups.
Mothers were blinded to the assigned BPSPs. There were three
study groups. The mothers in EXP-EXP used the experimental
Breast pump suction patterns
PP Meier et al
2
Journal of Perinatology
initiation BPSP until the OOL-II, and then switched to the
experimental maintenance BPSP for the remainder of the study.
Mothers in EXP-STD used the experimental initiation BPSP until
the onset of the OOL-II, and then switched to the standard
maintenance BPSP for the remaining study. Mothers in STD-STD
used the standard BPSP for both the initiation and maintenance
phases and served as the control group for this study.
All BPSPs were embedded in identical appearing cards that were
coded only by number and inserted into the breast pump. All
mothers were given an initiation card at the onset of the study, and
all were switched to a maintenance card with the OOL-II.
Sample and setting. This study was conducted in a Level III
neonatal intensive care unit in the Midwestern United States.
Criteria for sample selection included infant gestational age p34
weeks, anticipated neonatal intensive care unit stay of X15 days
and maternal decision to initiate lactation. All mothers who met
the inclusion criteria were approached for the study and 128
mothers agreed to participate. No mothers were excluded on the
basis of pre-existing medical conditions, perinatal complications or
other lactation-related risk factors. Of the 128 mothers who were
enrolled, 105 (82.0%) completed the study with usable data,
defined as at least nine consecutive days from the onset of the study
of complete milk output records. Supplementary Figure 1 details
the study design, randomization and completion rates of study
subjects. The completion rate among the groups was not
significantly different (EXP-EXP ¼33/42 (78.6%); EXP-STD ¼
34/43 (79.1%); STD-STD ¼38/43 (88.4%), w
2
¼1.77, df ¼2;
P¼0.413). There were no statistically significant differences
among the groups with respect to any maternal and infant
characteristics that might have influenced the dependent variables
in this study (Supplementary Table 1). The project was approved
by the Institutional Review Board of the research setting.
Measures
Effectiveness of the BPSPs. The effectiveness of BPSPs was
evaluated by three variables: OOL-II; daily maternal milk output;
and percentage of mothers that achieved a total daily milk output
of X350 and X500 ml.
The OOL-II was defined as the time at the onset of the first of
two consecutive pumping sessions for which the total milk output
was X20 ml. Four characteristics of the OOL-II were measured:
hours from the time of birth until OOL-II; hours from the first
pumping until OOL-II; number of pumping sessions from birth
until the OOL-II; and the total number of minutes spent
pumping until OOL-II. These data were calculated from the
mothers’ daily milk output records.
Daily milk output was measured volumetrically and recorded by
mothers for each pumping session during the study period using
the ‘My Mom Pumps for Me!’ milk output records, which have
been used in other BPSP studies.
6
Daily milk outputs of X350 and X500 ml were calculated to
determine the percentage of mothers who achieved the minimum
output needed to achieve exclusive human milk feeding for
premature infants at the time of neonatal intensive care unit
discharge (350 ml per day),
23
and a milk output that approximates
that of a mother who exclusively breastfeeds a healthy-term infant
at 4 to 7 days post-birth (500 ml per day).
5,11,23– 25
Efficiency of the BPSPs
The efficiency of the BPSPs was evaluated using three variables:
number of pumping sessions; number of minutes spent
pumping; and milk output per minute spent pumping
(calculated from total milk output and total minutes spent
pumping). These variables were obtained from the maternal milk
output records for each study day.
Maternal perceptions of effectiveness, efficiency, comfort and
convenience
Maternal perceptions of effectiveness, efficiency, comfort and
convenience were measured by questionnaires that contained
Likert-type and multiple-choice items derived from previous studies
of BPSPs.
6
Each questionnaire contained 13 to 18 Likert-type and
multiple-choice items. The Time 1 questionnaire measured
mothers’ perceptions of the initiation pattern, and was completed
within 72 h after giving birth. This questionnaire contained items
such as ‘How do you rate the overall comfort of this pattern?’ and
‘How do you rate the number of times that the pattern changes
rhythm during each pumping?’. The Time 2 questionnaire
measured mothers’ perceptions of the maintenance pattern as well
as their perceptions of differences between the initiation and
maintenance patterns. This questionnaire, which was completed
within 96 h after mothers changed from the initiation to the
maintenance pattern, asked mothers how strongly they agreed with
statements such as ‘The suction or pull of this pattern is better
than the one before’ and ‘The new pattern is better than the one
before at getting my milk out quickly.’ The Time 3 questionnaire
measured mothers’ perceptions of the maintenance pattern, and
was completed at the end of the study. This questionnaire asked
mothers questions such as, ‘How easy is it to know when you have
used the pumping pattern long enough to remove your milk?’ and
‘How do you rate the length of time that your nipple is pulled into
the tunnel of the breast shield?’
Procedure
Mothers were approached for inclusion in the study within 24 h
after birth if they and their infants met the inclusion criteria.
The study was explained, and written informed consent was
obtained. At the time of enrollment, mothers began use of the
breast pump according to the randomization plan, and received
standardized pumping instructions and guidance. All mothers were
taught to use simultaneous (e.g., pumping both breasts at the
same time) milk expression. Similarly, appropriate pumping
Breast pump suction patterns
PP Meier et al
3
Journal of Perinatology
pressures and correctly fitted breast shields were individualized for
each mother at this time. Mothers were instructed to use the breast
pump eight times daily for 15 min each pumping until the milk
output was at least 20 ml from the two breasts combined.
Thereafter, they were instructed to pump until they no longer saw
milk droplets for at least two consecutive minutes, ensuring the
available milk had been removed as completely as possible.
Mothers were taught to measure their pumped milk output
volumetrically and were shown how to record these volumes in
the milk output record. Mothers were given an initiation BPSP
card to be used in the Symphony pump, according to their
randomized group assignment. This card was used for all pumping
sessions until the OOL-II.
Mothers completed the Time-1 questionnaire within 72 h after
enrollment. If mothers experienced the OOL-II before hospital
discharge, they were given the maintenance card at that time. If
mothers were discharged before the onset of lactogenesis II, they
were provided with the maintenance card at the time of hospital
discharge with specific instructions about changing from the
initiation to the maintenance card once they had experienced two
consecutive pumping sessions with a total milk output of X20 ml
for each session. Mothers completed the Time-2 questionnaire
within 96-h of switching from the initiation to the maintenance
BPSP. The Time-3 questionnaires were completed at the end
of the study.
Data analysis
Data were analyzed using Microsoft Excel (Redmond, WA, USA) and
SPSS (version 15.0, Chicago, IL, USA). The data for each variable
were examined using univariate analyses. Categorical data were
compared using w
2
-analysis. Continuous, normally distributed data
were compared using analysis of variance. A posteriori comparisons
were performed on continuous data using Bonferroni tests. Ranked
data and non-normally distributed data were compared using
Kruskal–Wallis tests. A posteriori comparisons on these data
were performed using Mann–Whitney Utests. A Type I error of
5% was used for all tests of statistical significance.
Results
Effectiveness of the BPSPs
The Onset of Lactogenesis II. Of the 105 mothers, 3
(2 EXP-EXP and 1 STD-STD) failed to achieve the OOL-II by day
14, and were excluded from analyses related to the OOL-II. None
of the four measures for the OOL-II was statistically different
among the groups (Figure 1). However, all four measures
suggested an earlier and more efficient (e.g., fewer pumpings,
fewer minutes spent pumping) OOL-II for the EXP-STD mothers.
Daily maternal milk output. Mean daily maternal milk output
is depicted in Figure 2c. During the initial 5 days of the study,
0
20
40
60
80
100
120
140
EXP-EXP
(n = 31)
EXP-STD
(n = 34)
STD-STD
(n = 37)
Hours
Study Groups
0
5
10
15
20
25
30
EXP-EXP
(n = 31)
EXP-STD
(n = 34)
STD-STD
(n = 37)
Times Pumped
Study Groups
0
20
40
60
80
100
120
140
EXP-EXP
(n = 31)
EXP-STD
(n = 34)
STD-STD
(n = 37)
Hours
Study Groups
0
100
200
300
400
500
600
EXP-EXP
(n = 31)
EXP-STD
(n = 34)
STD-STD
(n = 37)
Minutes
Study Groups
Figure 1 Measures of the onset of lactogenesis II. (a) Hours from birth until onset of lactogenesis II (mean±s.d.); (b) hours from first pumping to onset of
lactogenesis II (mean±s.d.); (c) number of pumping sessions until onset of lactogenesis II (mean±s.d.); (d) total minutes of pumping until onset of lactogenesis II
(mean±s.d.).
Breast pump suction patterns
PP Meier et al
4
Journal of Perinatology
there were no significant differences among the groups. However,
starting on day 4, mean daily milk output for EXP-STD mothers
(335.4 ml) started to trend higher than for EXP-EXP (222.2 ml)
and STD-STD mothers (268.3 ml). These differences became
statistically significant starting on day 6, and remained
significantly higher through day 13. A posteriori comparisons,
when significant, demonstrated that milk output for EXP-STD
mothers was higher than for the other groups.
Mean cumulative maternal milk output for the study period is
depicted in Figure 3c. Starting on day 4, mean cumulative milk
output began to trend higher for EXP-STD mothers (575.8 ml),
when compared with EXP-EXP (413.3 ml) and STD-STD
(488.8 ml) mothers. Starting on day 8, EXP-STD mothers
demonstrated significantly greater cumulative milk output, and
this difference continued through the remainder of the study.
Percentage of mothers in each group with daily maternal milk
output X350 and X500 ml per day. Figures 2e and f depict
the percentage of mothers in each group with daily milk outputs
X350 and X500 ml, respectively. A greater percentage of
EXP-STD mothers achieved both the 350 ml and 500 ml
thresholds when compared with EXP-EXP and STD-STD mothers.
These differences were statistically significant for the X350 ml
threshold on day 7, and for the X500 ml threshold on days 11,
12 and 14.
Efficiency of the BPSPs
Daily minutes spent pumping. There were no statistically
significant differences among the groups in either the mean daily
number of pumpings or in the minutes spent pumping (Figures 2a
and b) or in the mean cumulative number of pumpings or
0
1
2
3
4
5
6
1
Mean Daily Number of Pumpings
Days post-birth
0
100
200
300
400
500
600
700
800
900
Mean Daily Milk Output (mL)
Days post-birth
* p 0.05
*
**
*
** **
0
20
40
60
80
Daily Milk Output
350 mL/day (%)
Da
y
s post-birth
* p < 0.05
*
0
25
50
75
100
125
Mean Daily Time (min)
Days post-birth
EXP-EXP (n = 33)
EXP-STD (n = 34)
STD-STD (n = 38)
EXP-EXP (n = 33)
EXP-STD (n = 34)
STD-STD (n = 38)
EXP-EXP (n = 33)
EXP-STD (n = 34)
STD-STD (n = 38)
EXP-EXP (n = 33)
EXP-STD (n = 34)
STD-STD (n = 38)
EXP-EXP (n = 33)
EXP-STD (n = 34)
STD-STD (n = 38)
EXP-EXP (n = 33)
EXP-STD (n = 34)
STD-STD (n = 38)
0
1
2
3
4
5
6
7
8
9
10
Mean Daily Efficiency (mL/min)
Days post-birth
*
* p < 0.05
0
10
20
30
40
50
60
70
Daily Milk Output
500 mL/day (%)
Da
y
s post-birth
* p < 0.05
*
**
1413121110987654321141312111098765432
11413121110987
6
54321 14
13
1211
10
98
7
65432
114
13
1211
10
98
7
65432
114
13
1211
10
98
7
65432
Figure 2 Daily measures of effectiveness and efficiency. (a) Daily number of pumpings (mean±s.d.); (b) daily pumping time (mean±s.d., in min); (c) daily milk
output (mean±s.d., in ml); (d) daily efficiency (mean±s.d., in ml per min); (e) percentage of cases with daily milk output X350 ml per day; (f) percentage of
cases with daily milk output X500 ml per day.
Breast pump suction patterns
PP Meier et al
5
Journal of Perinatology
minutes spent pumping (Figures 3a and b) throughout the study.
However, the STD-STD mothers trended consistently toward
more daily and cumulative minutes spent pumping than did
the EXP-EXP or EXP-STD mothers.
Milk output per minute of pumping time. This measure was
calculated by dividing the total daily milk output by the total daily
minutes spent pumping. Milk output per minute of pumping time
was higher for EXP-STD mothers than for EXP-EXP or STD-STD
mothers, a trend that emerged on day 4 post-birth and was
significantly higher on day 13 (Figure 2d). Cumulative milk
output per minute of pumping time demonstrated a similar trend
(Figure 3d), and was significantly higher for days 8 through 14.
Mothers’ perceptions of effectiveness, efficiency, comfort and
convenience
The only statistically significant difference in the Time-1
questionnaires revealed that STD-STD mothers perceived that the
initiation BPSP they used did not have enough changes in rhythm
when compared with EXP-EXP and EXP-STD mothers. For the
Time-2 questionnaire, eight statistically significant differences were
noted, all of which indicated that EXP-EXP mothers did not
perceive the new experimental maintenance BPSP as ‘comfortable’,
especially when compared with the experimental initiation BPSP
that these mothers had used. Only one statistically significant
difference was noted in the Time-3 questionnaires, which revealed
that EXP-EXP mothers did not like the ‘suction strength’ of the
new experimental maintenance BPSP.
Discussion
Mothers who are breast pump-dependent must substitute the
sucking stimulus and milk removal functions of the healthy-term
infant with a breast pump. This is the first study to compare the
effectiveness, efficiency, comfort and convenience of combinations
of BPSPs that mimic human infant sucking patterns during the
immediate post-birth period as well as later in lactation. The
findings of this study indicate that the combination of the
EXP-STD BPSPs is superior to the other combinations of BPSPs
for breast pump-dependent mothers with premature infants. We
hypothesize that the new EXP initiation BPSP provides uniquely
human sucking stimulation to the mammary gland during the
critical post-birth period when lactation is initiated. This
stimulatory effect is optimized when followed by the STD
maintenance BPSP, which was developed and tested extensively
for its effectiveness, efficiency, comfort and convenience
after the OOL-II.
The complex transition from the initiation to the maintenance
of lactation is a critical period and its successful completion has
been linked to subsequent milk output and/or duration of lactation
in human and animal studies.
11,26– 29
The primary trigger for
lactogenesis II for all mammals is the withdrawal of circulating
0
10
20
30
40
50
60
70
80
Mean Number of Pumping Sessions
Days post-birth
EXP-EXP (n = 33)
EXP-STD (n = 34)
STD-STD (n = 38)
EXP-EXP (n = 33)
EXP-STD (n = 34)
STD-STD (n = 38)
EXP-EXP (n = 33)
EXP-STD (n = 34)
STD-STD (n = 38)
EXP-EXP (n = 33)
EXP-STD (n = 34)
STD-STD (n = 38)
0
1000
2000
3000
4000
5000
6000
7000
8000
Mean Milk Output (mL)
Days post-birth
*
*
*
*
*
*
*
* p < 0.05
0
200
400
600
800
1000
1200
1400
1600
Mean Minutes Pumped
Days post-birth
0
1
2
3
4
5
6
Mean Milliliters per Minute (mL/min)
Days post-birth
*
*
*
*
*
*
*
* p 0.05
10141312111098765432
10141312111098765432 1
014
13
1211
10
98
76
5432
10141312111098765432
Figure 3 Cumulative measures of effectiveness and efficiency. (a) Cumulative number of pumping sessions; (b) cumulative number of minutes pumped;
(c) cumulative milk output (ml); (d) cumulative efficiency (ml per min).
Breast pump suction patterns
PP Meier et al
6
Journal of Perinatology
progesterone following the birth of the placenta, because
progesterone inhibits prolactin-regulated milk synthesis.
16,26
Thereafter, prolactin release by the anterior pituitary is
suckling-induced, and prolactin concentrations are directly
related to the intensity of the suckling stimulus.
26
The mammary gland is extremely sensitive to the effects
of prolactin in the early post-birth period.
26,29,30
During this
critical window, prolactin upregulates genes that promote rapid
proliferation and differentiation of the secretory cells in the
mammary gland, prevents apoptosis of secretory cells and
stimulates closure of the tight junctions in the mammary
epithelium.
16,26,29– 31
Although these processes are known to be
essential for the transition from the initiation to the maintenance
of lactation, recent evidence suggests that they also have a
programming role with respect to long-term milk output.
29– 32
Several studies in dairy cows have clearly demonstrated this
programming mechanism by randomly assigning animals to either
frequent (four times daily) or control (two times daily) milking
during the first 3 weeks post-birth. After the 3-week period, both
groups of cows were milked twice daily. Results revealed that
animals in the early frequent milking group produced significantly
greater milk throughout lactation.
29– 31
Laboratory findings
demonstrated that frequent milking during this critical period
resulted in higher concentrations of prolactin and greater secretory
cell number and differentiation, optimizing milk yield throughout
lactation.
29– 31
In our blinded, randomized clinical trial, the three groups of
mothers and infants did not differ significantly on any of the
characteristics that might potentially influence maternal milk
output, such as parity, delivery mode, infant gestational age,
previous breastfeeding experience or presence of maternal medical
complications. Similarly, the three groups of mothers received
identical pumping instructions, lactation care and access to
nonpharmacological interventions, such as skin-to-skin care, from
the same set of clinicians. The findings also reveal that the three
groups of women pumped a similar number of times and minutes
daily. Thus, common extraneous variables cannot explain the
greater maternal milk output noted in the EXP-STD mothers.
We conclude that the mechanism for the greater effectiveness,
efficiency, comfort and convenience in the EXP-STD mothers is the
combination of the two BPSPs used by these women. Specifically,
the EXP initiation BPSP provided an intensive rapid-rate stimulus
and burstpause pattern that is uniquely human, as other infant
mammals do not demonstrate this rapid non-nutritive sucking
pattern.
33
Additionally, the EXP initiation BPSP mimics sucking
that occurs during early breastfeeding, but not bottle-feeding in
healthy term infants.
18,19
Once the ‘milk comes in’, infants change
the sucking pattern to reflect the availability of milk. Specifically,
they suck rapidly until milk ejection occurs, and then switch to a
slower, more rhythmic suck in order to accommodate swallowing
and breathing after milk ejection.
14,18,19
This biphasic pattern is
replicated in the standard BPSP, and was used by EXP-STD
mothers in our study after the OOL-II.
By 4 to 7 days post-birth, exclusively breast-fed infants consume
approximately 500 to 600 ml of milk daily.
11,24,25,28
In our study,
EXP-STD mothers achieved a comparable mean daily milk output
by day 6 and maintained it through day 14, whereas mean milk
output for EXP-EXP and STD-STD mothers did not reach 500 ml
per day during the entire 14-day study period. Additionally, the
EXP-STD mothers achieved a mean daily milk output that was
considerably higher than that previously reported for breast pump-
dependent mothers of premature infants in early lactation.
4,28
In summary, this research suggests that the use of BPSPs that
mimic the sucking patterns of healthy-term infants during the
initiation and maintenance of lactation are more effective,
efficient, comfortable and convenient in breast pump-dependent
mothers with premature infants. Additionally, these findings add to
the anatomical and biochemical evidence that the initial post-birth
sucking patterns may serve a function beyond extracting milk, and
appear to have a role in the programming of critical processes
during the transition from the initiation to the maintenance of
lactation.
Conflict of interest
Dr Meier and Dr Engstrom have received research funding and
honoraria for projects from Medela. The other authors declare
no conflict of interest.
Acknowledgments
This study was partially supported by Medela (McHenry, IL, USA) and by
NIH Grant NR0100009.
References
1 Patel AL, Meier PP, Engstrom JL. The evidence for use of human milk in very
low-birthweight preterm infants. NeoReviews 2007; 8(11): e459– e466.
2 Meier PP, Engstrom JL, Patel AL, Jegier BJ, Bruns N. Improving the use of human
milk during and after the NICU stay. Clin Perinatol 2010; 37(1): 217–245.
3 Taylor SN, Basile LA, Ebeling M, Wagner CL. Intestinal permeability in preterm
infants by feeding type: mother’s milk versus formula. Breastfeed Med 2009; 4(1):
11– 15.
4 Cregan MD, De Mello TR, Kershaw D, McDougall K, Hartmann PE. Initiation of
lactation in women after preterm delivery. Acta Obstet Gynecol Scand 2002; 81(9):
870– 877.
5 Hill PD, Aldag JC, Chatterton RT, Zinaman M. Comparison of milk output between
mothers of preterm and term infants: the first 6 weeks after birth. J Hum Lact 2005;
21(1): 22– 30.
6 Meier PP, Engstrom JL, Hurst NM, Ackerman B, Allen M, Motykowski JE et al.
A comparison of the efficiency, efficacy, comfort, and convenience of two hospital-
grade electric breast pumps for mothers of very low birthweight infants. Breastfeed
Med 2008; 3(3): 141– 150.
7 Cregan MD, Mitoulas LR, Hartmann PE. Milk prolactin, feed volume and duration
between feeds in women breastfeeding their full-term infants over a 24 h period. Exp
Physiol 2002; 87(2): 207– 214.
Breast pump suction patterns
PP Meier et al
7
Journal of Perinatology
8 Ramsay DT, Hartmann PE. Milk removal from the breast. Breastfeed Rev 2005;
13(1): 5– 7.
9 Daly SE, Kent JC, Owens RA, Hartmann PE. Frequency and degree of milk removal
and the short-term control of human milk synthesis. Exp Physiol 1996; 81(5):
861– 875.
10 Daly SE, Owens RA, Hartmann PE. The short-term synthesis and infant-regulated
removal of milk in lactating women. Exp Physiol 1993; 78(2): 209–220.
11 Neville M, Keller R, Seacat J, Lutes V, Neifert M, Casey C et al. Studies in human
lactation: milk volumes in lactating women during the onset of lactation and full
lactation. Am J Clin Nutr 1988; 48: 1375– 1386.
12 Kent JC, Ramsay DT, Doherty D, Larsson M, Hartmann PE. Response of breasts to
different stimulation patterns of an electric breast pump. J Hum Lact 2003; 19(2):
179– 186.
13 Kent JC, Mitoulas LR, Cregan MD, Geddes DT, Larsson M, Doherty DA et al. Importance
of vacuum for breastmilk expression. Breastfeed Med 2008; 3(1): 11–19.
14 Mizuno K, Ueda A. Changes in sucking performance from nonnutritive sucking
to nutritive sucking during breast- and bottle-feeding. Pediatr Res 2006; 59(5):
728– 731.
15 Santoro Jr W, Martinez FE, Ricco RG, Jorge SM. Colostrum ingested during the first day of
life by exclusively breastfed healthy newborn infants. JPediatr2010; 156(1): 29–32.
16 Neville MC, Morton J, Umemura S. Lactogenesis: the transition from pregnancy to
lactation. Pediatr Clin North Am 2001; 48(1): 35– 52.
17 Drewett RF, Woolridge M. Sucking patterns of human babies on the breast. Early Hum
Dev 1979; 3(4): 315– 321.
18 Mathew OP, Bhatia J. Sucking and breathing patterns during breast- and bottle-feeding
in term neonates. Effects of nutrient delivery and composition. Am J Dis Child 1989;
143(5): 588– 592.
19 Bowen-Jones A, Thompson C, Drewett RF. Milk flow and sucking rates during breast-
feeding. Dev Med Child Neurol 1982; 24(5): 626–633.
20 Mitoulas LR, Lai CT, Gurrin LC, Larsson M, Hartmann PE. Effect of vacuum profile on
breast milk expression using an electric breast pump. JHumLact2002; 18(4): 353 360.
21 Mitoulas LR, Lai CT, Gurrin LC, Larsson M, Hartmann PE. Efficacy of breast milk
expression using an electric breast pump. J Hum Lact 2002; 18(4): 344–352.
22 Henderson JJ, Hartmann PE, Newnham JP, Simmer K. Effect of preterm birth and
antenatal corticosteroid treatment on lactogenesis II in women. Pediatrics 2008;
121(1): e92– e100.
23 Meier PP, Engstrom JL. Evidence-based practices to promote exclusive feeding of
human milk in very low-birthweight infants. NeoReviews 2007; 8(11): e467–e477.
24 Ingram JC, Woolridge MW, Greenwood RJ, McGrath L. Maternal predictors of early
breast milk output. Acta Paediatr 1999; 88(5): 493– 499.
25 Chen DC, Nommsen-Rivers L, Dewey KG, Lonnerdal B. Stress during labor and delivery
and early lactation performance. Am J Clin Nutr 1998; 68(2): 335–344.
26 Neville MC, Morton J. Physiology and endocrine changes underlying human
lactogenesis II. J Nutr 2001; 131(11): 3005S– 3008S.
27 Hurst NM. Recognizing and treating delayed or failed lactogenesis II. J Midwifery
Womens Health 2007; 52(6): 588– 594.
28 Hill PD, Aldag JC. Milk volume on day 4 and income predictive of lactation adequacy at
6 weeks of mothers of nonnursing preterm infants. J Perinat Neonatal Nurs 2005;
19(3): 273– 282.
29 Wall EH, Crawford HM, Ellis SE, Dahl GE, McFadden TB. Mammary response to
exogenous prolactin or frequent milking during early lactation in dairy cows. J Dairy
Sci 2006; 89(12): 4640– 4648.
30 Wall EH, McFadden TB. The milk yield response to frequent milking in early lactation
of dairy cows is locally regulated. J Dairy Sci 2007; 90(2): 716–720.
31 Hale SA, Capuco AV, Erdman RA. Milk yield and mammary growth effects due to
increased milking frequency during early lactation. J Dairy Sci 2003; 86(6):
2061– 2071.
32 Morton J, Hall JY, Wong RJ, Thairu L, Benitz WE, Rhine WD. Combining hand
techniques with electric pumping increases milk production in mothers of preterm
infants. J Perinatol 2009; 29(11): 757– 764.
33 Wolff PH. Sucking patterns of infant mammals. Brain Behav Evol 1968; 1:
354– 367.
Supplementary Information accompanies the paper on the Journal of Perinatology website (http://www.nature.com/jp)
Breast pump suction patterns
PP Meier et al
8
Journal of Perinatology

Supplementary resource (1)

... Most evidence for pumping-dependent mothers generally recommends pumping 6-8 times a day (27). According to one study, mothers are recommended to pump at least eight times every day for at least 15 min, with a significant increase in daily and cumulative milk yield (28). In our study, the majority of mothers met this standard for daily pumping frequency except for the first day (probably because the pumping time on the first day was less than 24 h, and milk volume actually starts to increase substantially earlier; first-day time = 24 hneonatal birth time). ...
... Feeling-related OOL II is the most commonly used indicator in research and clinical practice (33). However, since this method is subjective, a study proposed two consecutive milk production sessions ≥20 ml as a more practical definition (28). In the present study, the median time of OOL II-F or OOL II-Q in EP and LP was never >72 h (delayed lactogenesis II onset), indicating a better milk increase. ...
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... In our study, mothers were discharged from hospital earlier than their infants and they expressed milk at home during their infant hospital stay. Thus, we defined the day when mothers were able to express 20 mL milk (the total amount from both sides) for three consecutive times as the day of lactogenesis II onset [41]. ...
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... Interestingly, sodium appeared to most predictive of low milk volumes [42]. In this connection, small ion-selective probes are readily available to measure sodium in milk and have been validated against bench biochemical methods providing the potential for a point-of-care instrument [43] to monitor the initiation of lactation. This ability to measure markers early in lactation provides the clinician an opportunity to increase support and care of those mothers with known risk factors to maximise their likelihood of successfully establishing a milk production. ...
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Researchers have recently called for human lactation research to be conceptualized as a biological framework where maternal and infant factors impacting human milk, in terms of composition, volume and energy content are studied along with relationships to infant growth, development and health. This approach allows for the development of evidence-based interventions that are more likely to support breastfeeding and lactation in pursuit of global breastfeeding goals. Here we summarize the seminal findings of our research programme using a biological systems approach traversing breast anatomy, milk secretion, physiology of milk removal with respect to breastfeeding and expression, milk composition and infant intake, and infant gastric emptying, culminating in the exploration of relationships with infant growth, development of body composition, and health. This approach has allowed the translation of the findings with respect to education, and clinical practice. It also sets a foundation for improved study design for future investigations in human lactation.
... Secretory activation is associated with a significant increase in milk volume, and attainment of 20 ml in two consecutive expression sessions has been utilized as an indicator of the onset of secretory activation in mothers of preterm infants (Meier et al., 2012). Because mothers of VLBW infants bring their expressed milk to the NICU where the volume can be reliably measured, it is possible that volume attainment may be a simple and reliable indicator of secretory activation in this population of women. ...
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Objectives After completing this article, readers should be able to: 1. Identify obstacles to providing human milk for very low-birthweight infants. 2. Delineate components of human milk and mechanisms of protection. 3. Describe short-and long-term benefits of human milk. Abstract Many small and recently larger studies demonstrate the protective effects of human milk feedings for very low-birthweight (VLBW) infants, resulting in decreased mor-bidities. These benefits are due to the many unique properties of human milk that function synergistically to protect the infant from infectious, inflammatory, and oxidant injury. However, few VLBW infants in the United States receive maternal milk due to significant economic and social barriers. Additionally, the current research has not identified accurately the amount and timing of human milk feedings that provide maximal protection, which would enable optimal use of this scarce resource. Although the benefits of human milk feedings in VLBW infants have been demonstrated clearly, issues that remain unclear include dosing considerations and the economic implications of providing human milk feedings.
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The feeding of human milk (milk from the infant's own mother; excluding donor milk) during the newborn intensive care unit (NICU) stay reduces the risk of costly and handicapping morbidities in premature infants. The mechanisms by which human milk provides this protection are varied and synergistic, and appear to change over the course of the NICU stay. The fact that these mechanisms include specific human milk components that are not present in the milk of other mammals means that human milk from the infant's mother cannot be replaced by commercial infant or donor human milk, and the feeding of human milk should be a NICU priority. Recent evidence suggests that the impact of human milk on improving infant health outcomes and reducing the risk of prematurity-specific morbidities is linked to specific critical exposure periods in the post-birth period during which the exclusive use of human milk and the avoidance of commercial formula may be most important. Similarly, there are other periods when high doses, but not necessarily exclusive use of human milk, may be important. This article reviews the concept of "dose and exposure period" for human milk feeding in the NICU to precisely measure and benchmark the amount and timing of human milk use in the NICU. The critical exposure periods when exclusive or high doses of human milk appear to have the greatest impact on specific morbidities are reviewed. Finally, the current best practices for the use of human milk during and after the NICU stay for premature infants are summarized.
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To determine the mass of colostrum ingested by exclusively breastfed newborn infants during the first 24 hours of extrauterine life. Milk ingested during the first 24 hours of life by 90 healthy newborn infants was evaluated by use of a scale with high sensitivity. The masses were measured during 8-hour periods. Associations of the mass measured with prenatal and postnatal variables were tested. The mass of colostrum ingested was evaluated in 307 feedings, with 3.4+/-1 feedings recorded per 8-hour period of observation. Mean gain per feeding was 1.5+/-1.1 g. The daily mass of milk ingested by newborn infants was estimated at 15+/-11 g. This volume did not show a tendency to increase during the first 24 postnatal hours, nor was it related to perinatal or postnatal factors or to breastfeeding time. During the first 24 hours of life newborns ingested 15+/-11 g of milk.