New breast pumping technique helps preemies’ moms to improve milk supply

Jul 16 2009

Mothers of premature infants shouldn't rely solely on breast pumps to establish and maintain their breast milk supply, researchers at Lucile Packard Children's hospital and the Stanford University School of Medicine have found. Moms already have a simple, safe and free tool for assisting breast milk production: their own hands.

In the study, 67 new mothers of premature infants learned how to combine an electric breast pump with hand-expression techniques to extract milk. Unlike prior research showing poor milk production in preemies' moms, the subjects who used both hands and pump established plentiful milk supplies. By the end of the eight-week study, their average milk production exceeded the amount needed to feed a healthy 3-month-old, even though none of the women studied could nurse when their babies were born. The findings could have implications for women who have full-term infants, too.

"When I saw the data, I realized, oh, my gosh, this is impressive," said Jane Morton, MD, who led the study. Morton was the director of the breast-feeding medicine program at Packard Children's when the study, which appeared online July 2 in the Journal of Perinatology, was conducted.

"We were worried about mothers of preterm babies establishing any milk supply, much less an average-or-better supply," said William Rhine, MD, a neonatologist at Packard Children's and the study's senior author. The findings contradict widely held assumptions that premature delivery lessens the hormone signals needed to establish breast-feeding.

The women in the study had given birth at least 10 weeks early. Their fragile infants could not nurse for several weeks, so the mothers initially faced the challenge of establishing milk flow using only the suction of a pump. Although the women were given top-of-the-line electric breast pumps and lots of instruction and encouragement, Morton soon noticed that the first few subjects enrolled in the study were expressing only a fraction of their colostrum (the body's precursor to milk).

That's when she decided to break out the hand-expression expertise she'd garnered early in her 37-year career, before breast pumps were widely available. She began showing the subjects how to supplement electric pumping with hand expression, directing them to use this technique as often as possible until their milk came in. Once milk came in, mothers came to Packard Children's for regular, monitored pumping sessions. They were instructed how to use their hands, while pumping, to massage and compress areas of the breasts that felt firm. (The study techniques are demonstrated online at http://newborns.stanford.edu/Breastfeeding/index.html.)

The women tracked how often they pumped and used hand expression, and recorded how much milk they produced.

The study's most important finding was that women who expressed colostrum using hand expression at least six times daily during their infants' first three days of life had the most milk later on. By the end of the study, these women were producing 45 percent more milk than women who used hand expression fewer than twice a day during the first three postpartum days. Both groups used the electric pump with the same frequency.

"What you do in those first three days makes an enormous difference," Morton said, explaining that immediately after birth, the body is looking for signals about how much milk to produce. "Early on, it's not just how frequently you nurse but also how effectively you nurse." Hand expression helped women empty their breasts, sending a strong stimulus for future milk production.

Surprisingly, the hand-expression technique worked well even in women at risk for breast-feeding problems. Earlier studies showed that women who are overweight or obese, deliver by cesarean, have no prior breast-feeding experience, deliver twins or conceive via in vitro fertilization are at greater risk for under-production. However, in the current study, these risk factors did not predispose women to low milk volume. Fifteen women did not complete the study for reasons including death of their infant, transfer of the infant to another hospital, maternal health problems or decision to discontinue pumping.

The study will have implications not just for preemies' moms but also for women who give birth to full-term infants, Morton said. "If you have a baby who doesn't latch on and nurse effectively at first, this is a risk-free, cost-free, simple-to-learn way to express your colostrum, which can be fed to your baby," she said. Hand expression without a pump may be sufficient to help some women with slightly preterm infants ensure they produce enough milk in the future, she added.

And for mothers who notice a decrease in their milk supply after returning to work, hands-on pumping could make electric pumping more effective. A low milk supply is the most common reason moms discontinue breast-feeding in the first year, according to recent studies. "There's no reason to think that these same principles of milk production and pumping physiology shouldn't also apply to full-term mothers," said Rhine, who is also a professor of pediatrics at the School of Medicine. "They'll probably be able to get more milk sooner and in higher volumes by using these same tricks of the trade."

The study was funded by grants from the National Institutes of Health and by Medela, Inc. Medical Research in Switzerland, a manufacturer of breast pumps.