Research
Wendy Oddy, PhD and her Australian colleagues examined the relationship between the duration of breastfeeding and children’s educational performance at 10 years of age. A total of 2,900 pregnant women were enrolled in the study. Their children were assessed at 1, 2, 3, 5, 8, and 10 years of age using a questionnaire and physical examination. When 1,749 of the children were 10 years old, their parents gave the researchers permission to link their child’s study data to government databases containing test scores, specifically the results of the Western Australian Literacy and Numeracy Assessment (WALNA), which is administered annually to students in grades 3, 5, and 7 and measures achievement in mathematics, reading, writing, and spelling.

Results
Factors associated with greater academic achievement at age 10 included predominant breastfeeding, higher maternal education, higher family income, and reading to children ages 3 to 5 years. Predominant breastfeeding as defined by the World Health Organization (WHO), “The infant’s predominant source of nourishment has been breast milk. However the infant may also have received water or water-based drinks (sweetened or flavored water, teas, infusions, etc.); fruit juice; oral rehydration salts (ORS); drop and syrup forms of vitamins, minerals, and medicines; and folk fluids (in limited quantities. With the exception of fruit juice and sugar-water, no food-based fluid is allowed under this definition.”

• Predominant breastfeeding for six months or longer was associated with significant improvements in academic scores for mathematics, reading, and spelling, and approached significance for writing. But the results were gender specific: predominant breastfeeding for six months was associated with improved scores in mathematics, reading, writing, and spelling for boys, but not girls.
• Maternal education of 12 years or less and family income of $35,999 or less was associated with lower scores in mathematics, reading, writing, and spelling for boys and girls.
• Reading to children ages 3 to 5 years was associated with greater scores in reading, writing, and spelling for girls and mathematics for boys.

Why the discrepancy between boys and girls as it relates to breastfeeding? No one knows for sure, but sex hormones, particularly estrogen, with its neuroprotective effect may play a role. Both boys and girls have estrogen, but the level in girls is much greater, so neurologically, girls are already protected. If human milk also has a neuroprotective effect, the impact will be greater in boys, since they do not have the hormonal protection that girls have. Another possible explanation is that breast milk may affect boys and girls differently. For example, in nonhuman primates, unborn baby boys and girls (fetuses) respond differently to maternal stress. In boys, the corpus callosum (the part of the brain that allows the right brain to communicate with the left) shrinks, but in girls the opposite occurs. Perhaps the brains of boys and girls respond differently to breast milk as well. Lastly, it has been postulated that the maternal-infant interaction that comes from breastfeeding may have a greater affect on boys, who rely more than girls on interaction with their mothers to acquire language and cognitive skills. In other words, it’s possible that boys may need more attention and encouragement from their mothers in order to achieve on the same level as girls and breastfeeding facilitates this interaction.

Recommendations
Traditionally, girls have scored higher than boys on achievement tests, although the differences were not statistically significant, until now. Given that predominant breastfeeding for at least six months may help boys mature faster, for reasons not clearly understood, mothers of boys should be urged to breastfeed. At that same time, girls may benefit from predominant breastfeeding in other ways not yet known, so the take home message for all mothers is to breastfeed for at least six months and beyond, as recommended by the American Academy of Pediatrics and WHO.

I was stunned. My son didn’t sleep seven hours at night until he was nearly 7 months old. But then I recalled having given my daughter a bottle of formula the evening before, when no amount of breastfeeding would satisfy her. I had tried everything I could think of to calm her, but nothing worked. So with tears streaming down my face, I did the dastardly deed and gave her a bottle of formula.  She calmed immediately. And she slept. Seven straight hours.

Was the myth not a myth after all? Do babies who drink formula sleep longer stretches at night than babies who exclusively breastfeed? Do mothers of formula-fed babies sleep more soundly than mothers of breastfed babies? After just one bottle I was almost convinced, until I came across a recent study in the journal Pediatrics titled, “Infant Feeding Methods and Maternal Sleep and Daytime Functioning.”

Researchers wanted to know if mothers of formula-fed babies slept better than mothers who exclusively or partially breastfed. Eighty women participated in the study. They were divided into two groups. The first group was first- and second/third-time mothers from 9–16 weeks postpartum. The second group was first-time mothers from 2–13 weeks postpartum. Mothers were categorized as breastfeeding exclusively; formula feeding exclusively; or combo-feeding.

Mothers kept a daily log of their total nighttime sleep, how often they got up to feed their babies, and how long the were up each night. Each mother wore an actigraph, a wrist device that monitors body movement. Actigraphs give researchers an objective record of total sleep time, sleep efficiency, and sleep fragmentation. Mothers self-scored their level of “sleepiness” throughout the day using three standardized scales.

There was no difference in objective sleep, subjective sleep, or sleepiness between breastfeeding and formula-feeding moms. All moms were getting the same amount of sleep, were awake similar amounts of time at night, and were feeling equally tired during the day. (Welcome to the wonderful world of parenting.)

One interesting difference reported at postpartum week 10 was that breastfeeding moms had greater sleep efficiency compared to formula-feeding moms.

Why no significant differences? One theory is that even though breastfeeding mothers awaken more often during the night to feed their babies, they return to sleep more quickly. In other words, they sleep more efficiently. This could be due to the fact that preparing and then feeding a baby formula requires more activity than breastfeeding and creates a more wakeful environment for those mothers and their babies. Another possible explanation is that breastfeeding mothers are more likely to sleep during feedings. And another theory focuses on the milk-producing hormone, prolactin, which facilitates falling asleep and sleeping soundly by having a calming effect on both mom and baby.

Regardless of the reason, these results clearly show that concerns over lack of sleep are not a valid reason for choosing to bottle-feed rather than breastfeed.

As for my breastfeeding journey? After making some minor lifestyle changes (and taking a bit of Fenugreek—an herb used to increase milk production), my daughter and I are once again exclusively breastfeeding. And, funny thing, she is continuing to sleep seven hours at night!

No matter how you choose to feed your baby, rest assured that all babies will “sleep through the night” when the time is right.

Surprisingly, no mention is made of the role of breastfeeding as prevention.

Described by Kinney and Thach as, “[O]ne of the most mysterious disorders in medicine,” no single definition of SIDS is universally accepted. Currently SIDS is recognized as the sudden and unexplained death of an infant between 1 month and 1 year of age. Since the discovery that the prone sleeping position more than triples the risk for SIDS, the American Academy of Pediatrics (AAP) in 1992 recommended that all U.S. infants be placed on their backs to sleep. As a result, the incidence of SIDS among U.S. infants has decreased by nearly 50 percent from 1990 to 2005. Despite these reductions, SIDS remains the leading cause of postneonatal death in U.S. children and the third leading cause of infant mortality overall.

Not surprising, given that only 11 percent of U.S. babies are breastfed exclusively for six months.

The cause of SIDS remains unclear. Recent theoretical models include the Triple-Risk Model proposed in 1994. It focuses on the interaction between three factors—an underlying vulnerability, a critical developmental period, and an exogenous stressor. According to the Triple-Risk Model, “[S]IDS does not cause death in normal infants but, rather, only in vulnerable infants with an underlying abnormality.”

Notably absent among the “Recommendations for Risk Reduction and Counseling” is any mention of breastfeeding. Despite the fact that breastfeeding has been shown to reduce the risk of SIDS by nearly 50 percent at all ages throughout infancy. Moreover, research shows that 13 percent of all infant and young child deaths, the equivalent of 1.3 million lives, could be saved each year if 90 percent of children were breastfed exclusively for six months.

I am not suggesting that we discount the importance of placing babies on their back to sleep, or using a lightweight blanket or sleep sack to prevent overheating, or choosing a bed with a firm mattress that fits tight against the bed frame, or keeping babies within arms’ reach day and night. But we shouldn’t underestimate the role of breastfeeding—a strategy that has been shown to be the most cost effective of all child survival strategies.

The cause of SIDS is unclear as are the mechanisms for why breastfeeding decreases the risk of SIDS. Some data suggest that breast milk contains immunologic components that prevent infection and inhibits the release of pro-inflammatory cytokines, which are proteins that cause respiratory and cardiac dysfunction. In other words, breast milk may help prevent the defective cardio-respiratory state that Kinney and Thach theorize may play a role in SIDS.

Obviously more data is needed, but in the meantime, the protective effects of breastfeeding should not be ignored but rather recognized as a (S)trategy for preventing (I)nfant (D)eath and (S)aving babies.

Research
Nina R. O’Connor and colleagues conducted a systematic review to assess the link between pacifier use and breastfeeding. Twenty-nine studies were identified: four randomized controlled trials, 20 cohort studies, and five cross-sectional studies were evaluated.

The studies varied in terms of their definitions of pacifier use. Some studies classified pacifier use as only while the infants were in the hospital; however, most studies looked at pacifier use at 2 weeks, 1 month, 2 months, or 6 months of age. In addition, the classification of infants as “pacifier users” varied between any pacifier use, frequent use, and occasional use.

Breastfeeding outcome measures varied as well and included overall duration of breastfeeding, breastfeeding at set time points ranging from hospital discharge to 12 months of age, exclusive breastfeeding, predominant breastfeeding, and any breastfeeding (not specified as exclusive or predominant breastfeeding).

Results
Of the four randomized controlled trials that were evaluated, none found significant differences in breastfeeding outcomes based on pacifier use. Of the observational studies, 17 found that pacifier use was linked with an odds ratio, relative risk, or hazard ratio of shortened breastfeeding duration or shortened period of exclusivity. However, unlike randomized controlled trials, observational studies cannot prove causality, therefore no conclusions can be reached as to which came first—pacifier use leading to decreased breastfeeding or decreased breastfeeding leading to increased pacifier use. The remaining eight observational studies did not find statistically significant associations between pacifier use and breastfeeding outcomes.

In short, this review article highlights the need for more research on the relationship between pacifier use and breastfeeding. However, based on the strongest existing evidence, there is no indication that pacifier use has a detrimental effect on breastfeeding.

Recommendations
Ever since recent case-control studies suggested that pacifiers may provide a protective benefit for infants against SIDS (Sudden Infant Death Syndrome), the American Academy of Pediatrics (AAP) has recommended the use of pacifiers throughout the first year of life according to the following guidelines:

1. Pacifiers should be used only at naptime or bedtime and if the baby refuses the pacifier, he or she should not be forced to take it.
2. Pacifiers should not be coated with anything sweet.
3. Pacifiers should be cleaned often and replaced regularly.
4. For breastfed babies, pacifier use should be delayed until 1 month of age to ensure breastfeeding is firmly established.

None of the studies performed to date have directly assessed the effect of the AAP’s SIDS prevention recommendations on breastfeeding. Until such a study is conducted, we must rely on current evidence which shows that pacifier use does not directly cause adverse breastfeeding outcomes but may actually foretell breastfeeding difficulties. For now, pacifiers remain innocent until proven guilty.

This statement by Chief Justice Oliver Wendell Holmes in the late 19th century still holds true today. Breastfeeding offers countless advantages. Breast milk is composed primarily of whey proteins, which consist of secretory IgA antibodies, lactoferrin, lysozyme, and a plethora of other nutrients that are involved in host defense. Whey proteins are digested more easily by infants, promote gastric emptying, and also provide local gastrointestinal immunity against organisms entering the body via this route. Studies suggest that children who are breastfed have a decreased incidence of gastrointestinal infections, including necrotizing enterocolitis, as well as respiratory tract infections and otitis media. Breast milk also contains arachidonic acid (AA) and docohexaenoic acid (DHA) that are important in the formation of neuronal and retinal tissues in infants. In addition to all these important advantages, breast milk has recently been identified as having a protective effect on infants against sudden infant death syndrome (SIDS).

What is SIDS?
As the name implies, SIDS is the sudden and unexplained death of an infant less than one year of age. Most SIDS deaths are associated with sleep which is why the American Academy of Pediatrics recommended in 1992 and reaffirmed in 2009 that all infants be placed on their backs to sleep. Since that recommendation, the frequency of prone (face down) sleeping has decreased from 70 percent to 20 percent among United States (U.S.) infants and the SIDS rate has decreased by over 40 percent during that time period. Nevertheless, SIDS remains the leading cause of infant death beyond the neonatal period. Why? Although the answer is unknown, there are several other risk factors that may be involved. These factors include, but are not limited to tobacco exposure in the home, maternal smoking during pregnancy, excess bedding and clothing on the infant, and “co-sleeping” practices in which an infant shares a sleep surface with an adult.

Although an association between breastfeeding and SIDS has long been suggested, a recent study in the journal Pediatrics revealed that breastfeeding reduced the risk of sudden infant death syndrome by nearly 50 percent at all ages throughout infancy.

Research
Conducted in Germany from 1998 to 2001, the study included 333 infants who died from SIDS and 998 age-matched “control” subjects who were not affected by SIDS. Of the infants who died from SIDS, 59 percent were between the ages of 2 and 5 months demonstrating that the incidence is greatest in children less than 6 months of age.

Parents were asked to describe their infant’s feeding pattern as “breastfeeding only,” “partial breastfeeding” (defined as any formula or solids given in addition to breast milk), and “no breastfeeding.”  The infant’s feeding regimen was examined at 2 weeks of age, 1 month of age, and in the last month of life or in the month prior to the interview for the “control group” of infants. Researchers controlled for variables that are thought to contribute to an infant’s SIDS risk including maternal smoking in pregnancy, maternal family status, maternal age at delivery, socioeconomic status of the family, previous live births, birth weight of the infant, co-sleeping practices, pillow in the infant’s bed, temperature of the child’s room, pacifier use, and sleep position.

Results
Study results revealed that 83 percent of the controls and 53 percent of the SIDS infants were breastfed at 2 weeks of age. The corresponding percentages at one month of age were 72 percent and 40 percent. In the last month of life or for those in the control group, at one month prior to the interview, 40 percent of infants in the control group were breastfed compared to only 10 percent of the SIDS infants. Partial breastfeeding was associated with a reduced risk of SIDS as well. However, this result was not statistically significant which suggests that this finding could have been due to chance.

Recommendations
Breastfeeding reduced the risk of SIDS by at least 50 percent at all ages. Fifty-nine percent of the infants who died were 2 to 5 months of age; 73 percent of those who died were less than 6 months of age. These results suggest that the benefit of breastfeeding, especially exclusive breastfeeding for infants is significant at an early age and that every effort should be made to encourage breastfeeding at least until the infant reaches 6 months of age when the risk of SIDS becomes substantially lower.

It is not fully understood why breastfeeding decreases the risk of SIDS. Some data suggest that the immunologic components in breast milk prevent infection and inhibit the release of pro-inflammatory cytokines, proteins that cause respiratory and cardiac dysfunction.

We may not have all the answers, but we can be sure of one thing: breast milk is the best nutrition for babies, and this study highlights one more reason why breast milk is the way to go.