Caffeine and Breastfeeding

Caffeine and BreastfeedingDuring her pregnancy, my wife suffered through an absence of caffeine from her diet.

Apart from an occasional sip of my Mountain Dew or eating a small piece of chocolate, she abstained from her normal cups of coffee and eliminated soda consumption. Thus she was understandably delighted to read many great breastfeeding books which all stated she could safely drink coffee after giving birth even while breastfeeding.

None of the books provided strong references for their blanket statements about caffeine and breastfeeding. Both my wife and I were concerned about the laissez-faire approach they took regarding our daughter’s health. Many internet blogs highlight the uncertainty surrounding caffeine and breastfeeding while most pro-breastfeeding organizations seem to gloss over the controversy.

Caffeine and Breastfeeding

The American Academy of Pediatrics implies that up to three cups of coffee scattered throughout the day is fine and the La Leche League International mentions five cups of coffee as an upper bound. The National Institutes of Health concurs by recommending nursing mothers consume no more than the amount of caffeine in one cup of coffee per day. The NIH (alone among all references) does suggest that sensitive babies may react to a mother drinking even a single cup of coffee per day.

While we were in the hospital following my daughter’s birth, both lactation consultants, three nurses, and four pediatricians all confirmed that a cup of coffee a day would pose no problem for either mother or baby. The hospital even served her coffee as part of her standard mother-of-newborn meal options.

Once we returned home, it took two weeks for us to settle into a manageable routine. Armed with full confidence that she could enjoy her morning cup of coffee, my wife began the third week with her first cup of coffee in nearly one year. Since we keep good records of the timing and volume of all breast pumping, nursing, and bottle feeding, we could track when the first “tainted” breastmilk was consumed. The results on baby were unfortunately swift.

My wife drank a large cup of home-brewed dark coffee of approximately 12 ounces at 10am immediately after finishing a pumping session. She pumped again at 1pm and given the expected half-life of metabolized caffeine, we estimated an amount close to 120 mg of caffeine was physically present in her system at the time of the pumping session. At 4pm, my daughter first nursed from my wife then drank the remaining breastmilk from the 1pm pumping while my wife emptied her supply with additional pumping. We repeated a similar pattern three hours later.

From 4pm that day, our daughter refused to sleep and became noticeably agitated. We both attributed it to normal newborn fussiness. In particular, because we were both conscious of our baby’s caffeine intake, we assumed we were being hyper-vigilant to signs of caffeine. However, our daughter literally refused to sleep overnight. She alternated between annoyed crying and alert playfulness from 4pm until 10pm. She took several short one hour naps during the rest of the night and only ended up sleeping for five hours between 10pm and 10am the next morning. If my mother-in-law were not staying with us and we weren’t able to take alternating shifts of one-adult-always-awake, it would not have been a pleasant evening.

As we were still unsure of whether we were actually seeing effects of caffeine as opposed to just having observational bias, we repeated the same schedule on Sunday with my wife pumping more and nursing less as our daughter was too fussy and inpatient to nurse for much of the day. Following another 24 hours during which my daughter only slept for 12 hours (as opposed to the 18-20 hours she had been sleeping just two days before), we decided to go back to eliminating caffeine from my wife’s diet. My daughter slowly went back to her normal activity level over the next 48 hours and she is now (one full week later) on the same schedule as pre-caffeine days.

There are a host of issues preventing me from stating that caffeine intake caused my daughter’s altered sleep patterns. Major considerations include:

  • Observational Bias — Being alert to the presence of caffeine may have made us more alert to behavioral changes.
  • Observer Effect — We may have acted differently with our daughter in anticipation of behavioral changes and thus we may have caused the changes.
  • Data Entry Errors — With three different people recording data on feeding, pumping, sleeping, and activity, it is possible that we were more or less accurate than normal due to our interest in the results.
  • Non-caffeine Related Diet Changes — We have a varied diet and my wife ate different foods every day since we came home from the hospital. One or more of the foods not related to caffeine may have caused the changes in my daughter.
  • Illness– My daughter may have simply been exposed to a minor pathogen which manifested during the days she had trouble sleeping. Recovery from the illness may have mimicked what we attributed to weaning from caffeine.
  • Normal Baby Behavior — The most likely alternative explanation is that my daughter was three weeks old and reading too much into her schedule is foolish.

During the two nights when I stayed up the entire evening (and was lucky enough to sleep during the day thanks to my mother-in-law being here), I decided to do a comprehensive search for research related to the effects of caffeine while breastfeeding. I considered my questions to be basic:

1) Is it safe to consume caffeine while breastfeeding?
2) What amount of coffee can I drink during breastfeeding?
3) How much caffeine is transmitted through breastmilk?
4) Will small amounts of caffeine from breastmilk harm my baby?

Caffeine Transmitted Through Breastmilk

A 1979 study showed that caffeine lasts 17 times longer in newborns than in adults and only when babies are four and a half months old do they begin to eliminate caffeine at the same speed as adults. A 1995 paper in a pharmaceutical journal provides a possible explanation by showing that newborns lack the ability to metabolize a certain compound found in caffeine.However, following research showed that only 0.06 to 1.5 percent of the caffeine in a single cup of coffee consumed by a breastfeeding mother was later found in the urine of nursing babies.

A small study of 17 infants found that for infants being given caffeine as a therapy, the level of caffeine accumulated faster in breastfed infants than in infants taking formula. In addition, the breastfed infants eliminated less caffeine per day than the infants taking formula. Taken together, the results suggest that even small amounts of caffeine build up to high levels if newborns are continuously exposed to caffeine.

Caffeine and Breastfeeding Duration

The effect of caffeine consumption on breastfeeding duration is mixed. A German-language study summarized in the NIH PubMed database found that caffeine had a significantly-negative influence on breastfeeding duration for mothers in Bavaria. However, a contemporary English-language study on a large sample of babies born in Southwest Sweden found that “coffee consumption was not associated with duration of exclusive breastfeeding.” Additional studies make no mention of either coffee or caffeine on breastfeeding duration.

Caffeine and Breastmilk Composition

An older study in 1994 showed a change in the composition of breastmilk when mothers consumed more than three cups of coffee a day.

Problems With Research on Caffeine and Breastfeeding

A public health article points out that all research related to caffeine and breastfeeding is fraught with the problem that non-responders (the women who do not participate in the studies) are different than the responders. Failure to address this difference may result in studies drawing conclusions based on a biased sample of women who are healthier and more highly educated than average. Further problems occur when mothers fail to account for the presence of caffeine in cough or cold medications. An Australian survey article also points to a major issue with research on caffeine and breastfeeding: mothers in hot climates tend to drink higher amounts of soda containing caffeine. These alternative sources account for a substantial amount of caffeine for unwary nursing mothers.

My Personal Conclusion

My main conclusion following my brief survey of existing research on caffeine and breastfeeding is that there should be additional research. I accept that little caffeine is transmitted from mother to baby during a single feeding. However the data also show that the half-life of caffeine is three days for a baby my daughter’s age and that consistent, moderate amounts of caffeine may accumulate in her body faster than she can expel it. The harm of caffeine in my daughter largely stems from irritability and fussiness, but I suspect that if she misses sleep due to caffeine she will lose some of the benefits of restful sleep.

The current recommendation from the National Institutes of Health [no more than a single cup of coffee or equivalent caffeinated beverage] is the most conservative and it is obviously the advice that my wife and I will try to follow. Unfortunately, limiting caffeine to a single cup of coffee per day is difficult. The difficulty is exacerbated since drinking that morning cup of coffee will mean my wife can’t drink any caffeinated soda, can’t drink tea, can’t eat chocolate, can’t take any allergy or cold medication, and certainly can’t use any energy drinks.

The recommendation from the La Leche League International of a limit of 5 cups of coffee per day (around 400mg of caffeine) seems incredibly high. The Mayo Clinic suggests normal, healthy adults may experience harmful effects from just 4 cups of coffee per day. Given the “breastfeed at all costs” position of the LLLI, I suspect the organization is whitewashing the unknown risk of high caffeine consumption by breastfeeding mothers in favor of the known benefits of breastfeeding. If the only choices were:

A=drink 5 cups of coffee and breastfeed
B=don’t breastfeed

then I would certainly want my wife to choose A. Regrettably, that is a myopic view of the world and we (like most people) would prefer making an informed decision of an intermediate option. Thus I ignore the LLLI recommendation on this issue.

The American Academy of Pediatrics recommendation of an amount of caffeine equal to three cups of coffee, scattered throughout the day seems to be a good balance between practical use and health concerns. Of course, the AAP also notes that mothers should consider decreasing caffeine intake when their babies become more fussy or irritable.

My wife needs a morning cup of coffee to start her day and particularly to focus her attention while studying for her board examination. Since the importance of study for the board exam outweighs the likely negligible effect of one cup of coffee a day, we both agree that she should not give up caffeine entirely. If there is a specific benefit to an additional shot of caffeine during the day — late afternoon patient, extra study session, need to stay awake while driving — then I would be comfortable with another cup of coffee even though she is (admirably) forcing herself to have just one. The most difficult part of the caffeine limitation for her will likely be the emotional stress of acknowledging yet another accommodation she is forced to make for the benefit of our daughter.

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