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ORIGINAL ARTICLE
Combining hand techniques with electric pumping increases
milk production in mothers of preterm infants
J Morton, JY Hall, RJ Wong, L Thairu, WE Benitz and WD Rhine
Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA
Objective: Pump-dependent mothers of preterm infants commonly
experience insufficient production. We observed additional milk could be
expressed following pumping using hand techniques. We explored the effect
on production of hand expression of colostrum and hands-on pumping
(HOP) of mature milk.
Study Design: A total of 67 mothers of infants <31 weeks gestation were
enrolled and instructed on pumping, hand expression of colostrum and
HOP. Expression records for 8 weeks and medical records were used to
assess production variables.
Result: Seventy-eight percent of the mothers completed the study. Mean
daily volumes (MDV) rose to 820 ml per day by week 8 and 955 ml per
day in mothers who hand expressed >5 per day in the first 3 days. Week 2
and/or week 8 MDV related to hand expression (P<0.005), maternal age,
gestational age, pumping frequency, duration, longest interval between
pumpings and HOP (P<0.003). Mothers taught HOP increased MDV
(48%) despite pumping less.
Conclusion: Mothers of preterm infants may avoid insufficient
production by combining hand techniques with pumping.
Journal of Perinatology (2009) 29, 757–764; doi:10.1038/jp.2009.87;
published online 2 July 2009
Keywords: hand expression; insufficient milk production; breastmilk;
breastfeeding; lactation; preterm infants
Introduction
Many immediate and long-term benefits of breastfeeding for the
preterm infant and mother depend on exclusivity and duration,
1
with the strongest determinant of both being milk production.
2–4
Insufficient production in the first 6 weeks postpartum is the most
common reason for discontinuing lactation, 2.8 times more
frequent in mothers of preterm than those of term infants.
5–7
Also,
average milk output in mothers of preterm infants has been shown
to falter after 2 to 3 weeks, decline over the next 3 weeks and
consistently remain below that of mothers of term infants.
6
Mothers
of preterm infants are pump dependent for months before
establishing non-pump-dependent breastfeeding, making the
sustained, upward trajectory of milk production over months the
critical factor.
5,8
If nutrition from breastfeeding is inadequate for the preterm
infant, mothers must ‘triple feed’ (that is, breastfeed, bottle-feed
and pump) to maintain production. This regimen likely causes the
high breastfeeding attrition rates seen in mothers with low
production. Volumes <500 ml per day by postpartum week 6
predict early weaning.
3
In contrast, higher volumes facilitate the
transition from bottle (or tube) feeding to breastfeeding
4
by
reducing the effort required for milk transfer. Thus, maximizing
milk production is essential for prolonged breastfeeding.
For decades, efforts to improve production have focused
primarily on pumping schedules and pump design (that is,
electrical vs manual, single vs double, and vacuum patterns).
9–12
Other factors that can potentially affect establishment and
maintenance of lactation include ‘predetermined’ and ‘modifiable’
variables. Predetermined variables are maternal demographics,
perinatal issues and other variables inconsistently reported to affect
lactation. The influence of these variables in mothers of term vs
preterm infants may differ. For example, race and socioeconomic
factors influence initiation rates for term infant mothers, but not
for mothers who deliver prematurely and learn the protective
benefits of their milk.
7
Modifiable variables are pumping initiation
(time between birth and first expression), frequency and duration,
and the longest interval between two pumping sessions (potential
sleeping time). However, few studies have evaluated the use of
manual techniques to increase milk yield and/or milk quality.
13– 16
We have observed that pump suction alone often fails to remove
a significant fraction of milk as more can be expressed using
manual techniques. Before mature milk ‘comes in’, hand
expression may more effectively remove colostrum. Once volume
increases, a combination of pump suction, breast compression and,
if needed, hand expressionFcollectively referred to as ‘hands-on
pumping’ (HOP)Fmay remove a greater fraction of milk than
Received 10 December 2008; revised 5 April 2009; accepted 12 April 2009; published online
2 July 2009
Correspondence: Dr J Morton, Department of Pediatrics, Stanford University School of
Medicine, 401 Burgess Drive, Suite C, Menlo Park, CA 94025, USA.
E-mail: janemorton@sbcglobal.net
Journal of Perinatology (2009) 29, 757– 764
r
2009 Nature Publishing Group All rights reserved. 0743-8346/09 $32
www.nature.com/jp
pump suction alone. Hypothesizing that more milk is removed
using manual techniques, our objective was to use a prospective
observational cohort study to determine whether the use of two
manual techniques, hand expression of colostrum and HOP of
mature milk, could promote establishment and sustainability of a
sufficient milk supply. In addition, variables that may affect
lactation in preterm infant mothers were examined.
Methods
Study population
From 2004 to 2006, a convenience sample of eligible mothers of
preterm infants (< 1500 g infants, <31 weeks gestation) were
invited to participate in this observational study. Exclusion criteria
included a moribund infant, breast surgery, substance abuse,
severe maternal illness and known plans to transfer the infant to
another facility. Written informed consent was obtained from all
participants. The study was approved by the Stanford University
Institutional Review Board.
Study design
Mothers were given a Symphony pump (Medela Inc., McHenry, IL,
USA) for the duration of the study or the hospitalization of the
infantFwhichever was longer. Maternal perinatal information
and histories were obtained through chart review, questionnaires
and interviews. Mothers recorded their own milk expression
information, including date, time, duration and volume removed
from each breast for 8 weeks.
Hand expression and electric pumping
Participants were instructed to begin pumping within the first 6 h
postpartum. During lactogenesis phase I (before the onset of
copious milk production), they were instructed to ‘double pump’
(pump both breast simultaneously) 8 times per day for 15 min,
and to hand express colostrum as frequently as possible in
the first 3 postpartum days (Figure 1a). After lactogenesis II
(once mature milk ‘came in’), mothers were advised to pump
X8 times per day until they could express only drops. One
investigator (JM) gave the same instruction to each participant.
2.0000
1.8000
1.6000
1.4000
1.2000
1.0000
0.8000
0.6000
0.4000
0.2000
0.0000
120
100
80
60
40
20
0
derivative [g/s]
weight[g]
time [min]
0.00 30.0025.0020.0015.0010.005.00
Figure 1 Manual techniques. (a) Hand expression of colostrum; (b) Hands-on pumping (HOP); (c) Monitored, instructional pumping sessions and (d) Computerized
pictorial of milk expression from one breast as mother is taught HOP. Gradual ascending line represents cumulative volume; saw-toothed line depicts rate of
expression over 30 min.
Hand techniques and milk production
J Morton et al
758
Journal of Perinatology
As the capability of the mothers varied, partners and family
members were invited to learn the techniques to help with hand
expression.
HOP
Once discharged mothers were capable and available for
monitored, instructional pumping sessions (Figure 1b), they were
invited to return to the hospital and were observed for entire
pumping sessions utilizing a setup described by Ramsay et al.
17
Milk was collected via two tubes connecting the breast shields to
bottles placed on two electric scales, which were linked to computer
to record milk removal every 5 s over the entire (unlimited)
expression period (Figure 1c).
During each session, mothers were advised to use the maximum
comfortable vacuum and to accept only comfortable techniques.
They began each session by double pumping (both breasts at the
same time) with the electric pump, while simultaneously
compressing their breasts and massaging firmer areas.
Recommendations were given to support the breast shields to free
their hands for HOP. Sprays of milk from the nipple would be
observed in the tunnel of the breast shield, guiding mothers’
assessment as to where and how to use their hands. Additionally,
they could watch the computer screen demonstrating milk removal
from each breast (Figure 1d). When milk flow stopped,
double pumping was stopped and breasts were massaged briefly
(1 to 2 min). Following the massage, mothers were then instructed
to attempt removal of remaining available milk using whatever
techniques they chose. Some mothers resumed double pumping,
whereas others elected to single pump, using both hands and the
pump on one breast and then the other. A few chose to complete
the session using only hand expression. At home, all mothers
initiated expression by double pumping as described above and
then experimented with postmassage expression to find the most
effective, acceptable technique(s).
Variables affecting milk production
As the variables that affect establishment of lactation may differ
from those affecting maintenance, we examined predetermined and
modifiable variables at both 2 and 8 weeks postpartum. Only
participants who completed X6 days of records for weeks 2 and 8
were included in these assessments, because of day-to-day
differences in pumping variables and the inherent hazards of
estimations.
Predetermined variables were (1) maternal demographics
(age, education, marital status),
18
(2) perinatal issues (in vitro
fertilization (IVF), length of gestation,
19,20
route of delivery,
21
singleton vs multiples;
3,22
and infant birthweight
23
) and (3) other
variables inconsistently reported to affect lactation (maternal body
mass index (BMI),
24
and previous history of breastfeeding
18
).
Modifiable variables were pumping initiation (elapse between
birth and first expression), pumping frequency, pumping duration
and the longest interval between two pumping sessions (potential
sleeping time).
Statistical analyses
Statistical analyses were performed using SAS v9.2 Software
(SAS Institute Inc., Cary, NC, USA). The factors affecting changes
in milk production for an individual mother were analyzed using
ANOVA and with Student’s paired t-tests. Comparisons of milk
production volumes for any given timeframe were done using
unpaired t-tests. Pearson’s correlations were used to detect potential
differences in demographic status among compared groups. The
level of significance was set at a Pp0.05. All data are expressed as
mean±s.d.
Results
Demographics
A total of 71 mothers were recruited. Three refused and one was
ineligible due to breast implants. Of the 67 enrolled mothers,
52 remained in the study for the entire 8 weeks. Complete records
(X6 day of records for weeks 2 and 8) were available for 55 and
48 participants, respectively. Records of 19 participants were
incomplete for both weeks 2 and 8. Of these, nine participants
withdrew early (five infants expired, four mothers became too ill or
found the study too complicated). Six withdrew later because their
infants were either transferred (n¼3) or they discontinued
pumping (n¼3). The remaining four mothers recorded
inconsistently. To investigate whether pump-dependent mothers
using HOP could reach and sustain sufficient milk production over
the 8-week study, mean daily volumes (MDV) over the 3 days
before HOP instruction were compared to week 8 MDV for each
mother with complete pre- and postrecords. Of the 48 who
participated in the monitored instructional sessions, 42 had
complete records. No significant demographic differences were
noted between HOP participants and participants with complete
records (Supplementary Table 1).
Supplementary Table 1 shows the sample demographics for all
participants (Composite Group, n¼67), participants with
complete records for both weeks 2 and 8 (n¼48) and those with
incomplete records (n¼19). Mothers with complete records were
significantly older (P<0.001), had more formal education
(P<0.02) and were more likely to have undergone IVF (P<0.03).
Effect of hand expression of colostrum
Figure 2 shows the MDV for all 67 mothers (Composite Group) over
the 8-week study. All mothers were taught hand expression on the
first postpartum day and were instructed to use it as frequently as
possible. Forty-nine reported their frequency of use in days 1 to 3.
Based on the frequency of hand expression, these participants were
stratified into three self-selected groups: Group I (no/low, <2 times
per day, n¼15); Group II (medium, 2 to 5 times per day,
Hand techniques and milk production
J Morton et al
759
Journal of Perinatology
n¼18) and Group III (high, >5 times per day, n¼16; Table 1).
Group III MDV at week 1 through week 7 were statistically different
from Group I. Group II MDV at week 7 were also statistically
different from Group I. Week 2 and day 14 MDV were significantly
different between Group III and Groups I (P¼0.017) and II
(P¼0.029). By week 8, the difference in MDV of Group I
compared to Groups II and III was not significant (P¼0.060 and
0.058, respectively). No significant demographic differences among
the three groups were found. No statistical differences in mean
pumping frequency in Groups I, II and III over the first 3 days
postpartum or over days 1 to 14 were found (P¼0.113 and 0.538,
respectively).
Effect of HOP
The first day of HOP instruction was given at 20.6±9.6 days
postpartum. MDV decreased in 3/42 mothers (7.1%). Of these, one
developed mastitis, another failed to pump more than 4 times per
day and a third experienced a personal tragedy. Milk production
increased in 39/42 (92.9%) participants. Figure 3 demonstrates
pre- and postproduction in mothers taught HOP. MDV increased
48% (583±383 to 863±506 ml per day, P<0.003) after HOP
instruction. In addition, when comparing pre- and postinstruction
data, Table 2 demonstrates a statistically, but not clinically,
significant increase in the mean duration of pumping sessions
from 23.6 to 25.5 min per session (P¼0.035), a significant
increase of 54 min in the longest unpumped interval (P¼0.001)
and a decrease in daily pumping frequency (P¼0.003). When the
mean daily frequency is multiplied by the mean duration of each
session, the average daily pumping time remained unchanged
(153.4 to 150.4 min per day).
Effect of variables
For the 48 participants with complete records at 2 and 8 weeks, we
found that of the predetermined variables selected, maternal age
Figure 2 Mean daily volumes (MDV). MDV of expressed milk over the course of the 8-week study of three groups as defined by frequency of hand expression
during the first 3 postpartum days. Group I (<2 times per day, n¼15), Group II (2 to 5 times per day, n¼18) and Group III (>5 times per day, n¼16) volumes are
shown along with the output data of the Composite Group. Statistical comparisons using ANOVA were performed only between Groups I, II and III. P<¼0.05 *vs
Group I, wvs Groups I and II.
Table 1 Pumping variables of participants who were stratified into three groups based on frequency of hand expression use on postpartum days 1 to 3
Mean daily pumping frequency Mean daily volume; mean±s.d. (range)
Group Day 1–3 Day 1–14 Week 2 Day 14 Week 8
I(n¼15) 3.9±1.3 5.9±1.0 392±196 (120–779) 443±217 (149– 791) 658±267 (160– 1101)
II (n¼18) 4.4±1.6 5.9±1.3 448±318 (73– 1448) 488±352 (75– 1621) 859±430 (204– 2005)
III (n¼16) 5.0±1.5 6.3±1.3 710±402* (247–1711) 780±496
w
(228– 1958) 955±667
q
(445– 3160)
Group I (<2 times/day), Group II (2 to 5 times/day) and Group III (>5 times/day).
*P<0.005 compared to Group I and P¼0.023 compared to Group II, by ANOVA.
w
P<0.011 compared to Group I and P¼0.030 compared to Group II, by ANOVA.
q
Pp0.060 compared to Groups I and II, by ANOVA.
Hand techniques and milk production
J Morton et al
760
Journal of Perinatology
was inversely associated with week 2 MDV (P¼0.019, Pearson’s
correlation ¼0.316), but was no longer apparent by week 8
(P¼0.511, Pearson’s correlation ¼0.097). Gestational age was
inversely associated with week 8 MDV (R¼0.294, P¼0.043).
No other predetermined variables influenced MDV at 2 or 8 weeks.
Electric pumping frequency was the only modifiable variable
directly associated with week 2 MDV (P¼0.008). However, week 8
MDV were directly associated with electric pumping frequency
(P¼0.002), pumping session duration (P¼0.033) and longest
interval between pumping sessions (P<0.01).
High frequency pumping (X7 times per day) significantly
influenced MDV at 2 weeks (P¼0.030), but not at 8 weeks
(P¼0.170; Figure 4).
When participants with complete and incomplete records
were combined (that is, the Composite Group) at week 8,
MDV rose steadily to 820 ml with 75% of mothers having >500 ml
(Table 3). At this time point, there was also a slight increase in
pumping session duration, but no significant change in pumping
frequency or in the longest interval between any two pumping
sessions.
Discussion
The most intriguing findings in this study were the following: first
was the unfaltering and impressive breastmilk volume of preterm
infant mothers, who are considered to be at high risk for impaired
milk production; second was the finding that two practices not
routinely prescribed, hand expression of colostrum and HOP
expression of mature milk, may influence volume; and finally, the
lack of correlation between volume and variables believed to
influence production in breastfeeding mothers (type of delivery,
maternal BMI, history of previous breastfeeding, multiples, IVF)
suggests that these factors may be mitigated by techniques
supporting effective and frequent milk removal.
Mothers of preterm infants may remain pump dependent for
weeks to months before they can rely on the breastfeeding infant to
maintain their supply. Yet, most reports of milk output focus only
on the first month.
15,25– 27
Ours is the first report of a steady
increase in production over 8 weeks, which surpasses reference
levels for mothers of term infants. Hill et al.
6
who compared output
of mothers of preterm infants to that of mothers of term
breastfeeding infants over a 6-week period, found a decline after
2 to 3 weeks in mothers of preterm infants with similar birth
weight, gestational age and pumping frequency to those in our
study. For illustrative purpose only, Figure 5 shows week 6 MDV of
mothers of preterm infants in Hill’s study
6
of 541±450 ml with
48% >500 ml compared to week 6 MDV of our participants of
755±400 ml with 70% > 500 ml. Adequacy of milk output
(>500 ml per day) at week 6 appears to be a predictor for extended
breastfeeding of preterm infants.
0
200
400
600
800
1000
Average Milk Volume (mL)
863±506*
N=42
*P< 0.003Post-InstructionPre-Instruction
583±383
48%
Figure 3 Mean daily volumes (MDV) pre- and postinstruction of hands-on
pumping (HOP). In 42 mothers, MDV increased by 48%, comparing each
mother’s MDV 3 days before her first monitored pumping session (preinstruction)
to week 8 (postinstruction) MDV. Data are shown as mean±s.d. ml.
Table 2 Pre- and postinstruction of hands-on pumping (HOP): four pumping variables
Variable 3 Days before instruction Days 50 to 56 Pvalue
Daily pumping frequency; mean±s.d. (n) 6.5±1.4 (42) 5.9±1.4 (42) 0.003
Duration of each session (minute); mean±s.d. (n) 23.6±10.1 (38) 25.5±10.0 (36) 0.035
Daily longest interval (minute); mean±s.d. (n) 373±126 (42) 427±124 (42) 0.001
Mean daily volumes (MDV); ml per day (n) 583±383 (42) 863±506 (42) <0.003
Figure 4 The effect of pumping frequency on early (2 weeks) and late (8 weeks)
output. Mothers who pumped with a low frequency (<7 times per day) were
compared to those who pumped with a high frequency (X7 times per day). Data
are shown as mean±s.d. ml. High frequency pumping significantly influenced
mean daily volumes (MDV) at 2 weeks (P¼0.030), but not at 8 weeks
(P¼0.170).
Hand techniques and milk production
J Morton et al
761
Journal of Perinatology
In the first 3 postpartum days, mothers who used hand
expression >5 times per day (Group III) had MDV of 860±490
and 955±667 ml at 6 and 8 weeks, respectively. These volumes
exceeded the average intake (812 ml per day) reported for healthy
3-month-old breastfed term babies.
28
Our post hoc analysis of
expressed volumes suggests that hand expression of colostrum
increases milk production in the first 2 weeks and longer,
depending on the frequency of use on days 1 to 3. The robust MDV
in Group III mothers may reflect more frequent colostrum removal
(the combination of hand expression and pumping), or,
alternatively, more effective removal of colostrum with hand
expression may stimulate subsequent production.
Other interventions to improve effective removal of colostrum
have generally been reported to be unsuccessful. Oxytocin nasal
spray administered with each pumping in the first 5 days, increased
milk removal in primiparous mothers in one study,
29
but was
subsequently shown to have no significant effect.
30
Primiparous
mothers delivered by C-section who combine breastfeeding with
pumping do not improve colostrum removal during the first 72 h,
and they breastfeed for a shorter duration than mothers who only
breastfeed.
31
Yet, it remains common practice to provide newly
delivered breastfeeding mothers with pumps and instruction to
pump frequently to augment their production.
In mothers with established production, the degree rather than
the frequency of breast emptying is directly associated with
short-term control of milk synthesis.
32
Previous research suggests
the presence of an autocrine regulation of production with a
feedback inhibitor of lactation, which appears to act locally on the
apical portion of the alveolar cell to inhibit production.
33,34
Frequency of breastfeeding does not correlate with production, and
by one method of calculation, infants remove an average of 63 to
72% of available breastmilk per feed.
35
In Hill’s study,
6
exclusively
breastfed infants between 1 and 6 weeks of age fed more frequently
Table 3 Pumping variables of composite group
Postpartum week Daily frequency Pvalue Session duration
(min)
Pvalue Daily longest
interval (min)
Pvalue Mothers
(< 500 ml per day)
Volume
(ml per day)
Pvalue
Day 6–7 (n) 6.4±1.6 (59) F21.3±8.0 (43) F390±148 (59) F84% (48/57) 314±219 (57) F
2 6.4±1.4 (58) 0.85 22.3±8.7 (45) 0.61 389±128 (57) 0.97 62% (36/58) 489±338 (58) 0.001
3 6.5±1.4 (57) 0.62 23.0±9.4 (53) 0.36 383±120 (55) 0.76 47% (27/57) 591±358 (57) <0.001
4 6.4±1.3 (55) 0.81 23.8±8.1 (52) 0.14 395±122 (54) 0.85 26% (14/54) 659±332 (54) <0.001
5 6.3±1.3 (56) 0.78 25.5±9.5 (50) 0.025 401±119 (56) 0.67 30% (17/56) 711±386 (56) <0.001
6 6.4±2.1 (54) 0.97 25.0±8.8 (46) 0.046 398±118 (53) 0.75 30% (16/54) 755±400 (54) <0.001
7 6.0±1.5 (53) 0.23 25.2±9.3 (46) 0.037 414±136 (53) 0.38 28% (15/53) 776±432 (53) <0.001
8 6.0±1.5 (52) 0.20 24.9±9.6 (45) 0.06 427±143 (52) 0.18 25% (13/52) 820±480 (52) <0.001
All comparisons were made to postpartum days 6 to 7 using Student’s paired t-tests.
All data are shown as mean±s.d.
Data in parentheses indicate number of participants.
Figure 5 Comparison between milk output of mothers of term and preterm
infants. Milk outputs reported by Hill et al.
6
were compared to those of mothers
from our study (Composite Group only). The top line shows output of mothers
who used hand expression >5 times per day in the first 3 postpartum days
(Group III). (Adapted with permission from the J Hum Lact.)
Hand techniques and milk production
J Morton et al
762
Journal of Perinatology
than our study mothers expressed (8 vs 6 times per day). Once
mature milk ‘came in’, by using HOP, our participants may have
removed a greater percentage of milk per expression than
breastfeeding mothers, permitting them to maintain higher
production levels with less frequent expression. If study mothers
were dependent solely on pump suction, stopping when the flow
ended, available milk would have remained unexpressed.
The triple combination of external breast compression, pump
suction and the milk ejection reflex possibly removes a greater
fraction of milk from individual alveoli, and/or from a greater
percentage of alveoli, than ‘hands-off’ pumping. In support of this
theory, an experimental pump combining suction with a tactile
compression feature increased the rate of flow and the volume of
expressed milk compared to suction alone when the compression
was stopped.
36
Using ultrasonography of mammary ducts during
electric pumping, milk flow reversed with the abatement of the
milk ejection reflex in the nonexpressed breast.
17
Breast
compression during HOP may increase intramammary and
intraductile pressure, thereby enhancing milk removal. The effect
of seeing one’s own milk output increase with HOP is reassuring
and may be important, but its exact contribution to an increase in
milk production was not investigated.
Of the modifiable factors we studied, the pumping frequency
was important to the establishment and maintenance of lactation.
Our data support the importance of frequent colostrum removal in
the first 3 days.
5,20
The need to establish a lower threshold limit of
pumping frequency has long been recognized.
9
Yet, a precise
frequency more than five times per day has not been defined.
5,27
We found that the use of high-frequency pumping (X7 times per
day) was more important for establishment rather than for
maintenance of lactation (Figure 4). Some mothers, once HOP was
introduced, were able to maintain and increase volume despite
pumping less frequently. Beyond a variable maternal threshold,
increased frequency or duration of pumping may be less effective
than improved emptying.
Finally, our results suggest that predetermined variables do not
account for compromised production, although a larger sample
size is needed to confirm this finding. The inverse correlation
between gestational age and 8-week MDV may be spurious. Mothers
of larger vs smaller neonatal intensive care unit infants may have
failed to accurately record all the milk consumed by their
breastfeeding infants as measured by pre- and post-feed weights, a
potentially inaccurate method for assessing milk transfer.
37
Acceptability of combining manual techniques with electric
pumping was noted by Jones et al.
14
in a crossover study
measuring expressed milk with and without breast massage. They
found that output increased using massage and mothers initially
assigned to pump with massage voiced reluctance to pump without
it. In our study, when invited to comment on any aspect of
participation, most participants focused on the importance of
manual techniques. It was evident to participants who spoke with
nonparticipant mothers of preterm babies that they had an
advantage, and most attributed the difference to their use of
manual techniques. Impressed by the value of hand techniques,
participants volunteered to participate in educational videos to
comment on their experience and demonstrate these techniques to
other mothers and care providers.
The two hand techniques are demonstrated at: http://
newborns.stanford.edu/Breastfeeding/ (See ‘Hand Expressing
Milk’ and ‘Maximizing Milk Production’).
Limitations
Interpretation of our date may be limited due to several factors: our
expertise in HOP instruction, the lack of a control group, a single
hospital-based population with a high level of education and lack
of ethnic diversity. At our institution, it was not feasible to
randomize instruction because hand expression is commonly
practiced. The beneficial influence of two manual techniques,
hand expression of colostrum and HOP in mothers with established
production, requires confirmation in larger, appropriately
controlled studies. Additionally, the attention our participants
received make it questionable whether similar results could be
achieved in non-study mothers. A randomized study would
eliminate this concern with intent-to-treat analysis.
We surmise that HOP may be more advantageous if initiated
earlier, as soon as a mother can visualize sprays of milk in the
collecting system to guide her hand usage. Additionally, the wide
range of duration of expression in this study from 15 to 45 min,
averaging 25 min, suggests that specifying a time frame for
pumping duration for any mother, as mentioned by Kent et al.,
38
could negatively impact volume.
Conclusion
Although a larger, prospective, randomized, controlled trial is
needed to validate the observed benefits of manual techniques in
mothers of preterm infants, other pump-dependent mothers and
mothers otherwise at risk for insufficient milk production, our
results clearly suggest that mothers of preterm infants can attain
and sustain high production levels by combining the use of
electrical pumps with manual techniques, such as hand expression
and HOP. We propose that increased milk production may result
from more effective breast emptying rather than increasing the
frequency or duration of pumping sessions. Although the
availability and use of high quality pumps are important, we
speculate that reliance on electrical pumping alone may
compromise milk production potential in pump-dependent
mothers. Studies measuring the effectiveness of pumps in milk
removal should factor in the use of manual techniques.
Conflict of interest
The authors declare no conflict of interest.
Hand techniques and milk production
J Morton et al
763
Journal of Perinatology
Acknowledgments
We thank Birt Harvey, MD for his critical review of the article and Medela for
project facilitation. Also, we acknowledge Sarah Nomanbhoy, Ranee Bhutani,
Stewart Carlson and Ian Rhine for assistance with data entry and analyses, and
the Stanford GCRC nurses: Patricia Hartsell, Barbara Piane, Elizabeth Kogut and
Dorothy Inguillo for their hard work. This work was supported, in part, by Grant
M01 RR-000070 from the National Center for Research Resources, National
Institutes of Health, and in part by Medela Inc. Medical Research, Switzerland.
References
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Supplementary Information accompanies the paper on the Journal of Perinatology website (http://www.nature.com/jp)
Hand techniques and milk production
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