This randomized controlled trial compared milking the umbilical cord four times versus delaying cord clamping for 30 seconds in preterm neonates. The study found no significant differences in hemoglobin levels, hematocrit, or need for blood transfusions between the two groups. While milking appeared to provide comparable placental transfusion to delayed clamping, the authors call for larger studies with more standardized techniques given the limited research on cord milking.

1. Milking Compared with Delayed Cord Clamping to
Increase Placental Transfusion in Preterm Neonates
Alondra DeSantiago, Amanda Francois, Elizabeth Villegas, and Karen Wortham
Rabe, H., Jewison, A., Alvarez, R., Crook, D., Stilton, D., Bradley, R., & Holden, D. (2011). Milking Compared With Delayed Cord
Clamping to Increase Placental Transfusion in Preterm Neonates. Obstetrics & Gynecology, 117(2), 205-211.
doi:10.1097/AOG.0b013e3181fe46ff

2. Context and Rationale for the Study
Anemia due to prematurity is a significant problem seen in infants born before
33 weeks of gestation, and preterm neonates need blood transfusions in
order to help with this condition.
The placenta is a reservoir of fetal blood containing up to 40% of the fetal
blood with as much as 15-20 mL of blood in the umbilical cord, which may
be used to stabilize the infant’s circulatory system.
Optimal circulating blood volume for preterm neonates has been shown to be
between 75-100 mL/kg of body weight.

3. Context and Rationale (cont.)
Previous studies have found that a 30 second delay in umbilical cord clamping
helps with stabilization, leading to fewer transfusions needed in the
neonate’s first few days of life.This is now routine practice in hospitals.
Blood volume has been shown to increase by 18% by delayed clamping.
Recent studies on milking techniques also show higher hemoglobin values,
higher blood pressure, and less need for blood transfusions.

4. Research Hypothesis
In this study, researchers questioned which method would be more beneficial for
preterm babies: milking the cord four times or delaying cord clamping for 30
seconds.
● Researchers hypothesized that the two methods would produce different
values of hemoglobin and hematocrit.
● Exposure: milking the cord 4 times/waiting 30 seconds before clamping cord
● Health outcome: enhanced placento-fetal blood transfusion

5. Epidemiologic Study Design
This was a randomized, comparative trial at a single tertiary care center.
The study team recruited 58 neonates over an 18-month period from 212 women who
were potentially eligible participants.
Preterm neonates between 24 0/7 and 32 6/7 completed weeks of gestation were included
if antenatal informed consent could be obtained from the parents before delivery.
Before delivery, the fetuses were randomized into two groups.
31 neonates were randomized to the clamping group and were to have the umbilical cord
clamped at 30 seconds.

6. Epidemiologic Study Design (cont.)
27 neonates in the milking group would have the cord milked towards them four
times at a speed of 20 cm/2 seconds.
Randomization was based on computer-created tables performed by a person
not involved in the trial.
The randomization was stratified by gestational age, 24 0/7 to 27 6/7 completed
weeks of gestation and 28 0/7 to 32 6/7 weeks of gestation.
Blinding of the clinicians was not possible.

7. Results of the Study
The primary outcomes analyzed were the blood hematocrit and hemoglobin of
the preterm neonates at 1 hour after birth, and these outcomes were
analyzed throughout the first 6 weeks of life (or until first blood
transfusion).
The mean hemoglobin values for each group of preterm neonates at 1
hour after birth were 17.3 g/L for the group subjected to clamping and
17.5 g/L for the group subjected to milking (P=0.71).
The only difference in mean hemoglobin values during the first 6 weeks
was on day 42, where higher values were observed in the neonate
group subjected to milking.
There were no statistically significant differences between the groups in
leukocyte or platelet counts throughout the first 6 weeks of life.

8. Results of the Study (cont.)
The two groups had similar outcomes in regard to comorbidity, mortality, and
other secondary outcomes.
There was no significant difference in the number of preterm neonates in each
group that had to undergo blood transfusion (clamping group, 15; milking
group, 17; P=0.40).

9. Issues of Interpretation for the Study
Strengths
Randomization was used in this study to help control confounding and bias.
The randomization helped control confounding by ensuring that individual
differences between neonates did not affect the outcome.
Randomization was based on computer-created tables and was conducted by an
individual not involved in the study in order to eliminate some possible biased
influence.
In addition to computer generated randomization, the results of this randomization
were kept sealed in opaque envelopes which were opened preceding delivery.
This also kept experimenter bias from interfering in the randomization process.

10. Issues of Interpretation for the Study
Strengths (cont.)
This study attempted to eliminate confounding variables through restriction of
admission criteria. Inclusion and exclusion criteria were used.
Preterm neonates were only included if antenatal informed consent of parents
could be obtained.
Preterm neonates were excluded if there were multiple pregnancies (twins or
more), fetal hydrops, Rhesus sensitization, or other known congenital
abnormalities.
During analysis, confounding was also controlled through stratification of the
neonates by gestational age. This allowed for the experimenters to eliminate
potential confounders due to the age and maturity of the infant.

11. Issues of Interpretation for the Study
Weaknesses
The inclusion of another control group of neonates randomized to immediate cord
clamping would have been useful but was not ethically acceptable in a hospital
where clamping the cord after 30 seconds is a standard procedure.
It would have been preferable to use a more accurate measure of placental
transfusion other than hemoglobin and hematocrit after birth, but other
available methods are harder to perform on a large number of babies.
39 out of the 58 newborns were delivered via Cesarean section, which could have
altered the results in the way that placento-fetal blood transfusion occurred
different than in natural deliveries.
Blinding was not possible in order to eliminate experimenter bias.

12. Author’s Conclusions
This study has shown that, in preterm neonates, the effects from milking the
cord four times are similar to the effects from waiting 30 seconds before
clamping the cord.
The study demonstrated that neonates allocated to milking had similar
hemoglobin values after birth compared with the clamping group, indicating
a similar amount of blood transfer.
For future studies, researchers suggest that a more clear definition of the
interventions (only one clearly stated mode of milking or time interval
before clamping) will result in a better interpretation of the results and
ultimately help determine the most beneficial method.

13. Group Opinion
This article’s conclusions seem useful for:
Healthcare professionals and expecting parents to be informed of options when it comes time for their newborn’s cord to
be cut, rather than immediately after delivery.
This article could be used as a conversation starter for parents to discuss and begin planning with their healthcare
provider the best method of cord cutting for their baby.
Understanding that milking the umbilical cord may be the better option in some scenarios when time is crucial, as this
was proven to be the faster method and had comparable results to delayed clamping.
Some considerations in applying the results of this study include:
Only 58 neonates were studied. Perhaps increasing the number of neonates could provide health professionals with
more accurate, generalizable results.
Standardized procedures for each of the examined methods (milking and delayed clamping) should be created. Further
research will need to be done on these two methods. The authors mention that other healthcare workers should be
careful to fully document how each technique is used in future studies to be able to accurately compare the
methods.
There is comparatively little information known about cord milking compared to clamping, as mentioned by the study.
We think that though the results from this study show consistencies with other studies done on these two methods
of increasing placental transfusion, more research should be done on milking the umbilical cord before it is
introduced as an alternative routine practice to 30 second delayed cord clamping.
The disparity between treatment groups in the number of infants delivered via cesarean section may have biased
results. Future studies should be done in order to confirm that milking and delayed clamping truly have a
comparable outcome.