Currently, either method may be recommended for newborns who latch or suck poorly to encourage them to breastfeed, say the authors.
They base their findings on 68 mums whose newborns were latching on to the nipple or sucking poorly 12 to 36 hours after birth.
The mums were randomly assigned to either 15 minutes of using a breast pump or 15 minutes of manual breast milk expression in a bid to encourage their babies to breastfeed.
Afterwards, the amount of milk produced and suckled, pain levels, and confidence in breastfeeding were assessed. Breastfeeding rates were then monitored when the babies were 1 week, 1 month, and 2 months old.
There was no difference in the volume of breast milk expressed, pain levels, or confidence in breastfeeding between the two methods.
But mothers who expressed manually said they were more comfortable being seen to do so than mothers who used a breast pump.
And by the age of 2 months, breastfeeding rates were higher among those babies whose mums first expressed their breast milk by hand than those who first used a breast pump.
Almost all the mothers (97%) assigned to manual expression were breastfeeding compared with just under 73% of those assigned to the breast pump.
Most who used a breast pump at 2 months said they did so to store milk for occasions when they would be unable to feed their child in person. Just 15% said they did so to boost their milk supply.
The authors point out that breast pumping is a fast efficient method of milk expression, once the milk supply is established. But they add: "Providers should consider teaching hand expression instead of pumping to mothers of healthy term newborns feeding poorly after birth in cases where either method of expression might be appropriate."