Coffee and other caffeinated beverages are commonly consumed in pregnancy. In adults, caffeine may interfere with sleep onset and have a dose-response effect similar to those seen during insomnia. In infancy, nighttime waking is a common event. With this study, we aimed to investigate if maternal caffeine consumption during pregnancy and lactation leads to frequent nocturnal awakening among infants at 3 months of age.
All children born in the city of Pelotas, Brazil, during 2004 were enrolled on a cohort study. Mothers were interviewed at delivery and after 3 months to obtain information on caffeine drinking consumption, sociodemographic, reproductive, and behavioral characteristics. Infant sleeping pattern in the previous 15 days was obtained from a subsample. Night waking was defined as an episode of infant arousal that woke the parents during nighttime. Multivariable analysis was performed by using Poisson regression.
The subsample included 885 of the 4231 infants born in 2004. All but 1 mother consumed caffeine in pregnancy. Nearly 20% were heavy consumers (≥300 mg/day) during pregnancy and 14.3% at 3 months postpartum. Prevalence of frequent nighttime awakeners (>3 episodes per night) was 13.8% (95% confidence interval: 11.5%–16.0%). The highest prevalence ratio was observed among breastfed infants from mothers consuming ≥300 mg/day during the whole pregnancy and in the postpartum period (1.65; 95% confidence interval: 0.86–3.17) but at a nonsignificant level.
Caffeine consumption during pregnancy and by nursing mothers seems not to have consequences on sleep of infants at the age of 3 months.
Comments
Evidence no longer supports caffeine avoidance for human milk donors
To the Editor,
National milk bank guidelines from USA, UK or Germany among others do not mention caffeine consumption in their sections on Donors selection. They stick to the elegant proposition: "whereof one cannot speak, thereof one must be silent". On the other hand, many local milk banks adopt a more cautious approach when selecting donors, therefore making their supplies run low. There is now ample proof that caffeine is safe. Hopefully it will help milk banks keep up with the demand for human milk.
There was paucity of evidence on the safety of caffeine consumption among pregnant or nursing women, but recent studies by Santos et al. (1) and by Loomans et al. (2) have shed light on this important issue within neonatal care. Fortunately, both studies are large enough to fully assess the safety of caffeine.
Both papers underline that caffeine consumption is almost universal during pregnancy and lactation. At 16 weeks of gestation, prevalence of heavy consumption (>255 mg/day) was 35.3% according to Loomans. Only 1 of the 885 Santos' women reported no caffeine consumption.
Santos et al. report that maternal caffeine consumption, even in large amounts during lactation, had no consequences on sleep of the infant at 3 or 12 months of age, as well as on child crying at 3 months of age. Loomans et al. show that prenatal caffeine intake was not associated with a higher risk for fetal growth restriction, prematurity, hyperactivity, emotional symptoms or overall problem behaviour.
A Cochrane review has suggested that the use of prophylactic caffeine for preterm infants reduces the duration of need for positive pressure ventilation and the rate of patent ductus arteriosus ligation, as well as demonstrates an improved rate of survival without developmental disability (3). The studies included in this review used a loading dose of 20 mg/kg of caffeine citrate and 10 or 5 mg/kg/day as maintenance dose.
The pharmacokinetics of caffeine in breast milk after oral administration of caffeine to lactating mothers has been extensively studied. It is already known that caffeine concentration in breast milk remains low (4). The intake of caffeine by the infants whose nursing mothers intake was 500 mg. per day has been estimated to be 0.3-1.0 mg/kg/day (5).
The findings on caffeine in preterm neonates combined with the evidence from nursing mothers' research support the conclusion that in the neonatal unit caffeine is not only effective but safe. Premature infants are the most frequent recipients of donor breast milk. Yet, many milk banks discard life-saving milk from women willing to donate, who drink coffee. After reading Santos' and Loomans' papers, we think it is time to update local milk banks restriction policies considering mothers who are breastfeeding and drinking caffeine. Otherwise, shortage of donors is expected given the high prevalence of caffeine consumption during lactation.
REFERENCES
1. Santos IS, Matijasevich A, Domingues MR. Maternal caffeine consumption and infant nighttime waking: prospective cohort study. Pediatrics. 2012;129(5):860-8.
2. Loomans EM, Hofland L, van der Stelt O, van der Wal MF, Koot HM, Van den Bergh BR, Vrijkotte TG. Caffeine Intake During Pregnancy and Risk of Problem Behavior in 5- to 6-Year-Old Children. Pediatrics. 2012 Jul 9. [Epub ahead of print]
3. Henderson-Smart DJ, De Paoli AG. Prophylactic methylxanthine for prevention of apnoea in preterm infants. Cochrane Database Syst Rev. 2010(12):CD000432.
4. Blanchard J, Weber CW, Shearer LE. Methylxanthine levels in breast milk of lactating women of different ethnic and socioeconomic classes. Biopharm Drug Dispos. 1992;13(3):187-96.
5. Ryu JE. Effect of maternal caffeine consumption on heart rate and sleep time of breast-fed infants. Dev Pharmacol Ther. 1985;8(6):355-63.
Conflict of Interest:
None declared