Mothers hoping to get a little more shut-eye by formula-feeding should put that notion to bed. It's just not true, according to a new study in the December issue of Pediatrics published online Monday.
No matter whether moms breast-fed, formula-fed or did a combination
of both, they got the same amount of sleep and considered themselves
equally exhausted. This study gives women on the fence another reason to commit to
breastfeeding, conveying well-documented health benefits for baby -
and mother. The American Academy of Pediatrics recommends babies be
exclusively breast-fed for six months and continue to receive breast
milk for at least a year.
The research, from West Virginia University (WVU), also turns another
new motherhood truism on its head — that annoying and completely
unrealistic admonition to “nap when baby naps.”
“When a woman has a baby, she is given a whole Welcome to Motherhood
basket of advice,” says Hawley Montgomery-Downs, an assistant professor
of psychology and coordinator of WVU's behavioral neuroscience program.
“A lot is anecdotal and very little is supported by empirical evidence.”
Most new mothers have likely heard that formula-feeding — and maybe a
touch of rice cereal, as my grandma insisted — will help their babies
sleep longer. It's true that formula takes babies longer to digest,
while breast milk is processed more fully and quickly because of its
composition. But even if bottle-fed babies are sleeping longer, their
moms are not, say the researchers.
Miriam Labbok, director of the Carolina Global Breastfeeding
Institute at the University of North Carolina at Chapel Hill calls the
results a “helpful finding for the field.”
“The perception is that the breast-feeding mom is up day and night,
always breast-feeding,” says Labbok. “But when you're bottle-feeding,
you're up day and night always bottle-feeding, too.”
That was borne out by the data collected from the new mothers, who
were tracked from the beginning of the second week after their baby was
born until the end of the twelfth week. The women — divided into groups
who breast-fed, formula-fed and alternated back and forth — wore wrist
actigraphs, a watch-like device that records movement to determine when
sleep occurs. Each morning, they used a PDA to rank their sleep quality
from 0 to 100. They also shared how many times they thought they awoke
during the night and how long they thought they stayed awake. To top it
off, whenever they fed their baby during the day, they would use the PDA
to enter how sleepy they felt right then.
This wealth of postpartum data yielded a surprising conclusion: there was no difference among the groups.
That, of course, raised other questions. “If it's true that
breast-feeding infants wake up more often but their mothers don't, there
has to be something going on,” says Montgomery-Downs.
Maybe breast-feeding moms wake only to latch their babies on, then
return to dreamland. I can certainly vouch for that happening. Or maybe
formula-feeding moms catapult themselves into a more alert state as they
pad downstairs, flip on the light to prepare a bottle and move around
more than a breast-feeding mom.
Yet even though these new moms are certifiably wiped out, they're not
sleep-deprived: the 80 mothers surveyed reported getting 7.2 hours of
sleep a night.
Yet even if they're not technically deprived of sleep, they are
legitimately being deprived of good sleep. The moms tell of sleeping in
bursts, a phenomenon the researchers refer to as “sleep fragmentation.”
“This is not a sleep disorder,” says Montgomery-Downs. “This is what new
Since sleep fragmentation is the main issue with new moms' sleep, it
makes little sense to nap alongside your baby — unless you know your
baby is likely to snooze for at least 90 minutes, which is how long an
adult's sleep cycle lasts. It's better to just go to bed early and take
advantage of the longer chunks of sleep an infant typically experiences
For those breast-feeding moms who crave the occasional night off that
formula-feeding provides (since anyone can give a baby a bottle, while
only Mom, obviously, can breast-feed), Montgomery-Downs suggests pumping
in between sleep cycles, then handing off a bottle of breast milk to
Montgomery-Downs called the study's results “good, objective
research” to fend off well-intentioned naysayers such as “practitioners
and friends and mothers-in-law who say, 'We know it's hard, we know
“It ought to be reassuring to breast-feeding moms,” she says. “Stopping breastfeeding is not going to be the answer.”
Read more: http://healthland.time.com/2010/11/08/breast-feed-or-formula-feed-in-terms-of-sleep-its-a-wash/#ixzz14ihmBNSK