Caffeine consumption among expectant or new mothers does not appear to affect the nighttime sleeping habits of their newborns, new Brazilian research indicates.
The conclusion is based on an analysis of sleeping patterns among more than 4,200 infants until the age of three months, in light of the caffeine-consumption habits of their mothers both before and after delivery.
Researchers looked at two beverages: coffee and mate, a hot tea-like beverage popular in their area.
The team, led by study author Dr Ina Santos of the postgraduate programme in epidemiology at the Federal University of Pelotas in Brazil, reports its observations online and in the journal Pediatrics.
The authors note that it is very common for newborns to experience nighttime awakenings, and that caffeine consumption has long been linked to sleep disruption and insomnia among adult drinkers.
How the study was done
To see whether caffeine consumption among pregnant women and nursing mothers affects their child's sleep, Santos' team tracked more than 4,200 infants who were born in 2004 in the city of Pelotas, with a specific focus on 885 infants within that group.
All the new mothers were interviewed at the hospital immediately after delivery and then three months later to gauge their caffeine-drinking habits. Heavy coffee drinkers were defined as those who consumed 300 milligrams or more of caffeine per day, either via coffee or some other caffeinated beverage.
According to the Mayo Clinic, two to four cups of brewed coffee contain between 200 and 300 milligrams of caffeine.
All the newborns were examined at birth, with follow-up exams conducted at three months. At that point, the mothers provided details on their child's sleep habits during the prior 15 days, including total day and night sleep hours and bed-sharing practises.
Defining night awakenings as being any time parents were awakened by a child's arousal, the researchers also asked parents to tally the frequency of their child's nighttime waking episodes and indicate any apparent causes for such awakenings. Frequent awakening was defined as a child waking up three or more times per night.
Mothers also made an overall assessment of the quality of their baby's sleep habits.
Heavy coffee drinking did affect babies
All but one of the mothers regularly consumed some caffeine. About one in five was considered a heavy caffeine drinker during pregnancy, and more than 14% continued to drink caffeine heavily as their newborns reached three months of age.
As for the babies, nearly 14% were frequent nighttime wakers.
Although there was some indication that nighttime wakening was more prevalent among babies whose mothers were heavy caffeine consumers during pregnancy and nursing, the connection was not statistically significant.
The researchers concluded that there was no evidence that caffeine consumption, at any particular level, could be linked to sleep-pattern disruptions among the infants.
Lona Sandon, a registered dietitian and assistant professor of clinical nutrition at the University of Texas Southwestern in Dallas, said although caffeine consumption among pregnant women and new mothers has long been a concern among paediatricians, it has certainly never risen to the level of alarm over alcohol consumption or cigarette use.
Still good idea to limit coffee during pregnancy
"Coffee drinking in that situation has never been perceived as evil or bad," she said. "But, depending on the paediatrician, oftentimes mothers are encouraged to limit caffeine intake during pregnancy, often to just one cup of coffee a day - or to stop drinking it altogether. And that's because it's a central nervous system stimulant that can increase the baby's heart rate in utero, and can cause some distress. And then, after delivery, the baby might be getting the caffeine through the breast milk."
"But it should be pointed out that the 300 milligrams of coffee they're talking about here is really not such an outlandish amount," Sandon said. "It's really about three cups of a standard six- to eight-ounce cup of coffee. And that's just one grande Starbucks, really."
"At that amount, it could be that coffee drinking is more likely a problem for the mother than for the infant," she added. "The child's sleep patterns might not be disrupted. But it could actually be disrupting the mother's sleep patterns at a time when it's already difficult for the mother to get adequate rest."
Dr Aparajitha Verma, medical director of the Methodist Hospital Sleep Disorder Center in Houston and an assistant professor in the neurology department at Methodist Neurological Institute, cautioned that nailing down maternal caffeine consumption's specific impact on newborns is an extremely tricky endeavour.
"Nighttime wakening among babies that age can be due to so many different things," she said. "So to tease out caffeine's role is going to be very difficult. I think it's a valid concern, and there certainly might be a connection. Caffeine's half-life is typically five to seven hours, and it's well known to cause sleep disruption among adults. But whether that translates into trouble among these women's infants is something that clearly we just don't know yet."
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For more about caffeine's impact on sleep, visit the National Sleep Foundation.
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