Cribsheet

by Emily Oster

  23. Type 1 diabetes, also known as juvenile diabetes, is the type that develops in childhood and requires insulin injections. In 2017 researchers in northern Europe using a rich trove of data from two countries published a paper arguing that babies who are not breastfed are more likely to develop this disease (Lund-Blix NA, Dydensborg Sander S, Størdal K, et al. Infant feeding and risk of type 1 diabetes in two large Scandinavian birth cohorts. Diabetes Care 2017;40[7]:920–27). This study was motivated by a set of small case-control studies that showed similar effects (see references in this paper). To be more precise, the authors showed that the babies of mothers who never try to breastfeed at all are more likely to develop type 1 diabetes than those who breastfeed even a bit.

  I am skeptical of these conclusions, despite the quality of the data and large sample size. The main issue is that in this population, not breastfeeding at all is very unusual—only 1 to 2 percent of women make this choice. These women differ in many ways from those who breastfeed (including being more likely to be diabetic themselves), and even with good data we cannot hope to see all these ways. When a choice is so unusual, we really worry about what drives it.

  The researchers’ conclusions may be correct, but we simply need more data (ideally from a setting where not breastfeeding at all is more common) to be confident.

  Leukemia is the most common type of childhood cancer, and it has been hypothesized that it is linked to not breastfeeding. Like SIDS, this is rare, and researchers studying it typically use a case-control design: recruiting families with children with leukemia and a comparison group of children without a cancer diagnosis. In 2015 a large review article combined a number of small studies of this, and argued that together they show a significant reduction in the risk of cancer for children who are breastfed (Amitay EL, Keinan-Boker L. Breastfeeding and childhood leukemia incidence: A meta-analysis and systematic review. JAMA Pediatr 2015;169[6]:e151025).

  However, as other authors note, this conclusion is fragile (Ojha RP, Asdahl PH. Breastfeeding and childhood leukemia incidence duplicate data inadvertently included in the meta-analysis and consideration of possible confounders. JAMA Pediatr 2015;169[11]:1070). In the main analysis—the one on which the primary conclusions are based—researchers do not take into account any other differences between the children with leukemia and those without besides the cancer diagnosis. But many other factors differ across the two groups. Taking into account even just the differences in the ages of the mothers makes the effects much smaller and not statistically significant. The effect may well be even less compelling if we adjusted for more differences.

  24. Der G, Batty GD, Deary IJ. Effect of breast feeding on intelligence in children: Prospective study, sibling pairs analysis, and meta-analysis. BMJ 2006;333(7575):945.

  25. Specifically, when they look at the results from independent evaluators, they do not see differences in verbal IQ. These show up only in the evaluations done by the study personnel. This difference suggests evaluator bias.

  26. Der G, Batty GD, Deary IJ. Results from the PROBIT breastfeeding trial may have been overinterpreted. Arch Gen Psychiatry 2008;65(12):1456–57.

  27. Krause KM, Lovelady CA, Peterson BL, Chowdhury N, Østbye T. Effect of breast-feeding on weight retention at 3 and 6 months postpartum: Data from the North Carolina WIC Programme. Public Health Nutr 2010;13(12):2019–26.

  28. Woolhouse H, James J, Gartland D, McDonald E, Brown SJ. Maternal depressive symptoms at three months postpartum and breastfeeding rates at six months postpartum: Implications for primary care in a prospective cohort study of primiparous women in Australia. Women Birth 2016;29(4): 381–87.

  29. Crandall CJ, Liu J, Cauley J, et al. Associations of parity, breastfeeding, and fractures in the Women’s Health Observational Study. Obstet Gynecol 2017;130(1):171–80.

  CHAPTER 5: BREASTFEEDING: A HOW-TO GUIDE

  1. Sharma A. Efficacy of early skin-to-skin contact on the rate of exclusive breastfeeding in term neonates: A randomized controlled trial. Afr Health Sci 2016;16(3):790–97.

  2. Moore ER, Bergman N, Anderson GC, Medley N. Early skin-to-skin contact for mothers and their healthy newborn infants. Cochrane Database Syst Rev 2016;11:CD003519.

  3. Balogun OO, O’Sullivan EJ, McFadden A, et al. Interventions for promoting the initiation of breastfeeding. Cochrane Database Syst Rev 2016;11:CD001688.

  4. McKeever P, Stevens B, Miller KL, et al. Home versus hospital breastfeeding support for newborns: A randomized controlled trial. Birth 2002;29(4):258–65.

  5. Jaafar SH, Ho JJ, Lee KS. Rooming-in for new mother and infant versus separate care for increasing the duration of breastfeeding. Cochrane Database Syst Rev 2016;(8):CD006641.

  6. Chow S, Chow R, Popovic M, et al. The use of nipple shields: A review. Front Public Health 2015;3:236.

  7. Meier PP, Brown LP, Hurst NM, et al. Nipple shields for preterm infants: Effect on milk transfer and duration of breastfeeding. J Hum Lact 2000;16(2):106–14.

  8. Meier PP et al. Nipple shields for preterm infants.

  9. Walsh J, Tunkel D. Diagnosis and treatment of ankyloglossia in newborns and infants: A review. JAMA Otolaryngol Head Neck Surg 2017;143(10):1032–39.

  10. O’Shea JE, Foster JP, O’Donnell CP, et al. Frenotomy for tongue-tie in newborn infants. Cochrane Database Syst Rev 2017;3:CD011065.

  11. Dennis CL, Jackson K, Watson J. Interventions for treating painful nipples among breastfeeding women. Cochrane Database Syst Rev 2014;(12):CD007366.

  12. Mohammadzadeh A, Farhat A, Esmaeily H. The effect of breast milk and lanolin on sore nipples. Saudi Med J 2005;26(8):1231–34.

  13. Dennis CL et al. Interventions for treating painful nipples.

  14. Jaafar SH, Ho JJ, Jahanfar S, Angolkar M. Effect of restricted pacifier use in breastfeeding term infants for increasing duration of breastfeeding. Cochrane Database Syst Rev 2016;(8):CD007202.

  15. Kramer MS, Barr RG, Dagenais S, Yang H, Jones P, Ciofani L, Jané F. Pacifier use, early weaning, and cry/fuss behavior: A randomized controlled trial. JAMA 2001;286(3):322–26.

  16. Howard CR, Howard FR, Lanphear B, Eberly S, DeBlieck EA, Oakes D, Lawrence RA. Randomized clinical trial of pacifier use and bottle-feeding or cupfeeding and their effect on breastfeeding. Pediatrics 2003;111(3):511–18.

  17. This study also evaluates pacifier use on breastfeeding. For most outcomes and specifications, it found no impact of early pacifier use on breastfeeding success; for one specification researchers found some significant effects, although these effects are small and do not survive an adjustment for the multiple hypothesis testing.

  18. Brownell E, Howard CR, Lawrence RA, Dozier AM. Delayed onset lactogenesis II predicts the cessation of any or exclusive breastfeeding. J Pediatr 2012;161(4):608–14.

  19. Brownell E et al. Delayed onset lactogenesis II.

  20. Brownell E et al. Delayed onset lactogenesis II. Garcia AH, Voortman T, Baena CP, et al. Maternal weight status, diet, and supplement use as determinants of breastfeeding and complementary feeding: A systematic review and meta-analysis. Nutr Rev 2016;74(8):490–516. Zhu P, Hao J, Jiang X, Huang K, Tao F. New insight into onset of lactation: Mediating the negative effect of multiple perinatal biopsychosocial stress on breastfeeding duration. Breastfeed Med 2013;8:151–58.

  21. Ndikom CM, Fawole B, Ilesanmi RE. Extra fluids for breastfeeding mothers for increasing milk production. Cochrane Database Syst Rev 2014;(6):CD008758.

  22. Bazzano AN, Hofer R, Thibeau S, Gillispie V, Jacobs M, Theall KP. A review of herbal and pharmaceutical galactagogues for breast-feeding. Ochsner J 2016;16(4):511–24.

  23. Bazzano AN et al. A review of herbal and pharmaceutical galactagogues for breast-feeding. Donovan TJ, Buchanan K. Medications for increasing milk supply in mothers expressing breastmilk for their preterm hospitalised infants. Cochrane Database Syst Rev 2012;(3):CD005544.

  24. Spencer J. Common problem
s of breastfeeding and weaning. UpToDate. Accessed 2017. Available at https://www.uptodate.com/contents/common-problems-of-breastfeeding-and-weaning.

  25. Mangesi L, Zakarija-Grkovic I. Treatments for breast engorgement during lactation. Cochrane Database Syst Rev 2016;(6):CD006946.

  26. Butte N, Stuebe A. Maternal nutrition during lactation. UpToDate. Accessed 2018. Available at https://www.uptodate.com/contents/maternal-nutrition-during-lactation.

  27. Lust KD, Brown J, Thomas W. Maternal intake of cruciferous vegetables and other foods and colic symptoms in exclusively breast-fed infants. J Acad Nutr Diet 1996;96(1):46–48.

  28. Haastrup MB, Pottegård A, Damkier P. Alcohol and breastfeeding. Basic Clin Pharmacol Toxicol 2014;114(2):168–73.

  29. Haastrup MB et al. Alcohol and breastfeeding.

  30. https://www.beststart.org/resources/alc_reduction/pdf/brstfd_alc_deskref_eng.pdf.

  31. Haastrup MB et al. Alcohol and breastfeeding.

  32. Be Safe: Have an Alcohol Free Pregnancy. Revised 2012. https://www.toxnet.nlm.nih.gov/newtoxnet/lactmed.htm.

  33. Lazaryan M, Shasha Zigelman C, Dagan Z, Berkovitch M. Codeine should not be prescribed for breastfeeding mothers or children under the age of 12. Acta paediatrica 2015;104(6):550–56.

  34. Lam J, Kelly L, Ciszkowski C, Landsmeer ML, Nauta M, Carleton BC, et al. Central nervous system depression of neonates breastfed by mothers receiving oxycodone for postpartum analgesia. J Pediatr 2012;160(1):33–37.

  35. Kimmel M, Meltzer-Brody S. Safety of infant exposure to antidepressants and benzodiazepines through breastfeeding. UpToDate. Accessed 2018. Available at https://www.uptodate.com/contents/safety-of-infant-exposure-to-antidepressants-and-benzodiazepines-through-breastfeeding.

  36. Acuña-Muga J, Ureta-Velasco N, De la Cruz-Bértolo J, et al. Volume of milk obtained in relation to location and circumstances of expression in mothers of very low birth weight infants. J Hum Lact 2014;30(1):41–46.

  CHAPTER 6: SLEEP POSITION AND LOCATION

  1. Horne RS, Ferens D, Watts AM, et al. The prone sleeping position impairs arousability in term infants. J Pediatr 2001;138(6):811–16.

  2. Dwyer T, Ponsonby AL. Sudden infant death syndrome and prone sleeping position. Ann Epidemiol 2009;19(4):245–49.

  3. Spock B, Rothenberg M. Dr. Spock’s Baby and Child Care. New York: Simon and Schuster, 1977.

  4. There is a good example in a study from the 1990s (Dwyer T, Ponsonby AL, Newman NM, Gibbons LE. Prospective cohort study of prone sleeping position and sudden infant death syndrome. Lancet 1991; 337[8752]:1244–47). In this study, researchers attempted to follow a cohort over time and study what determines SIDS deaths. They enrolled 3,110 people, and in that population, there were 23 SIDS deaths. The researchers were able to obtain information on sleep position for 15 of these deaths, which wasn’t enough to draw statistical conclusions.

  5. Fleming PJ, Gilbert R, Azaz Y, et al. Interaction between bedding and sleeping position in the sudden infant death syndrome: A population based case-control study. BMJ 1990;301(6743):85–89.

  6. Ponsonby AL, Dwyer T, Gibbons LE, Cochrane JA, Wang YG. Factors potentiating the risk of sudden infant death syndrome associated with the prone position. N Engl J Med 1993;329(6):377–82. Dwyer T et al. Prospective cohort study of prone sleeping position.

  7. Engelberts AC, De Jonge GA, Kostense PJ. An analysis of trends in the incidence of sudden infant death in the Netherlands 1969–89. J Paediatr Child Health 1991;27(6):329–33.

  8. Guntheroth WG, Spiers PS. Sleeping prone and the risk of sudden infant death syndrome. JAMA 1992;267(17):2359–62.

  9. Willinger M, Hoffman HJ, Wu K, Hou J, Kessler RC, Ward SL, Keens TG, Corwin MJ. Factors associated with the transition to nonprone sleep positions of infants in the United States: The National Infant Sleep Position Study. JAMA 1998;280(4):329–35.

  10. Branch LG, Kesty K, Krebs E, Wright L, Leger S, David LR. Deformational plagiocephaly and craniosynostosis: Trends in diagnosis and treatment after the “Back to Sleep” campaign. J Craniofac Surg 2015;26(1):147–50. Peitsch WK, Keefer CH, Labrie RA, Mulliken JB. Incidence of cranial asymmetry in healthy newborns. Pediatrics 2002;110(6):e72.

  11. Peitsch WK et al. Incidence of cranial asymmetry in healthy newborns. Pediatrics 2002;110(6):e72.

  12. Van Wijk RM, Van Vlimmeren LA, Groothuis-Oudshoorn CG, Van der Ploeg CP, Ijzerman MJ, Boere-Boonekamp MM. Helmet therapy in infants with positional skull deformation: Randomised controlled trial. BMJ 2014;348:g2741.

  13. Carpenter R et al. Bed sharing when parents do not smoke.

  14. Vennemann MM, Hense HW, Bajanowski T, et al. Bed sharing and the risk of sudden infant death syndrome: Can we resolve the debate? J Pediatr 2012;160(1):44–48.e2.

  15. CDC Fact Sheets, “Health Effects of Secondhand Smoke.” Updated January 2017. https://www.cdc.gov/tobacco/data_statistics/fact_sheets/secondhand_smoke/health_effects/index.htm.

  16. Scragg R, Mitchell EA, Taylor BJ, et al. Bed sharing, smoking, and alcohol in the sudden infant death syndrome. New Zealand Cot Death Study Group. BMJ 1993;307(6915):1312–18.

  17. Horsley T, Clifford T, Barrowman N, Bennett S, Yazdi F, Sampson M, Moher D, Dingwall O, Schachter H, Côté A. Benefits and harms associated with the practice of bed sharing: A systematic review. Arch Pediatr Adolesc Med 2007;161(3):237–45. doi:10.1001/archpedi.161.3.237.

  18. Ball HL, Howel D, Bryant A, Best E, Russell C, Ward-Platt M. Bed-sharing by breastfeeding mothers: Who bed-shares and what is the relationship with breastfeeding duration?. Acta Paediatr 2016;105(6):628–34.

  19. Ball HL, Ward-Platt MP, Howel D, Russell C. Randomised trial of sidecar crib use on breastfeeding duration (NECOT). Arch Dis Child 2011;96(7):630–34.

  20. Blair PS, Fleming PJ, Smith IJ, et al. Babies sleeping with parents: Case-control study of factors influencing the risk of the sudden infant death syndrome. BMJ 1999;319(7223):1457–62.

  21. Carpenter RG, Irgens LM, Blair PS, et al. Sudden unexplained infant death in 20 regions in Europe: Case control study. Lancet 2004;363(9404):185–91.

  22. Tappin D, Ecob R, Brooke H. Bedsharing, roomsharing, and sudden infant death syndrome in Scotland: A case-control study. J Pediatr 2005;147(1):32–37. Scragg RK, Mitchell EA, Stewart AW, et al. Infant room-sharing and prone sleep position in sudden infant death syndrome. New Zealand Cot Death Study Group. Lancet 1996;347(8993):7–12.

  23. Tappin D et al. Bedsharing, roomsharing, and sudden infant death syndrome in Scotland.

  24. Tappin D et al. Bedsharing, roomsharing, and sudden infant death syndrome in Scotland. Carpenter RG et al. Sudden unexplained infant death in 20 regions in Europe.

  25. Scheers NJ, Woodard DW, Thach BT. Crib bumpers continue to cause infant deaths: A need for a new preventive approach. J Pediatr 2016;169:93–97.e1.

  CHAPTER 7: ORGANIZE YOUR BABY

  1. Weissbluth M. Healthy Sleep Habits, Happy Child. New York: Ballantine Books, 2015.

  2. Galland BC, Taylor BJ, Elder DE, Herbison P. Normal sleep patterns in infants and children: A systematic review of observational studies. Sleep Med Rev 2012;16(3):213–22.

  3. Mindell JA, Leichman ES, Composto J, Lee C, Bhullar B, Walters RM. Development of infant and toddler sleep patterns: Real-world data from a mobile application. J Sleep Res 2016;25(5):508–16.

  CHAPTER 8: VACCINATION: YES, PLEASE

  1. CDC. Measles (Rubeola). Available at https://www.cdc.gov/measles/about/history.html.

  2. Oster E. Does disease cause vaccination? Disease outbreaks and vaccination response. J Health Econ 2017;57:90–101.

  3. The story of Wakefield and his impact on vaccine rates is told in much more detail in Seth Mnookin’s wonderful book Panic Virus. New York: Simon & Schuster, 2012. Brian Deer also has an excellent set of articles summarizing the issues in the British Medical Journal (Deer B. Secrets of the MMR scare: How the vaccine crisis was meant
to make money. BMJ 2011;342:c5258).

  4. Wakefield AJ, Murch SH, Anthony A, Linnell J, Casson DM, Malik M, Berelowitz M, Dhillon AP, Thomson MA, Harvey P, Valentine A, Davies SE, Walker-Smith JA. Retracted: Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. Lancet 1998;351(9103):637–41.

  5. Committee to Review Adverse Effects of Vaccines. Adverse effects of vaccines: Evidence and causality. National Academies Press, 2012.

  6. The report includes the flu vaccine, but many of those links focus on adults, and I will focus here on childhood vaccinations.

  7. Verity CM, Butler NR, Golding J. Febrile convulsions in a national cohort followed up from birth. I—Prevalence and recurrence in the first five years of life. Br Med J (Clin Res Ed) 1985;290(6478): 1307–10.

  8. Chen RT, Glasser JW, Rhodes PH, et al. Vaccine Safety Datalink project: A new tool for improving vaccine safety monitoring in the United States. The Vaccine Safety Datalink Team. Pediatrics 1997;99(6):765–73.

  9. Madsen KM, Hviid A, Vestergaard M, et al. A population-based study of measles, mumps, and rubella vaccination and autism. N Engl J Med 2002;347(19):1477–82.

  10. Jain A, Marshall J, Buikema A, Bancroft T, Kelly JP, Newschaffer CJ. Autism occurrence by MMR vaccine status among US children with older siblings with and without autism. JAMA 2015;313(15): 1534–40.

  11. Gadad BS, Li W, Yazdani U, et al. Administration of thimerosal-containing vaccines to infant rhesus macaques does not result in autism-like behavior or neuropathology. Proc Natl Acad Sci USA 2015;112(40):12498–503.