From the Research Summaries Archives: Breastfeeding

Lamaze International launched Science & Sensibility to bring updates and analysis on new research to childbirth educators and other birth professionals as early as possible. We know you are on the front lines, answering questions about newsworthy research and bringing the latest evidence-based information to expectant women every week. The decision to launch Science & Sensibility meant that we would retire Lamaze’s quarterly e-newsletter, Research Summaries for Normal Birth. We know how much many of you appreciated Research Summaries, so over the next couple of months, we will be moving its archives to Science & Sensibility. We’re excited to have all of Lamaze’s research resources in one place. If you miss getting Research Summaries in your inbox, you can sign up to receive Science & Sensibility posts by email. Just click on “Subscribe to Science & Sensibility” on the right hand side of this page.

To kick off our From the Research Summaries Archive Series, and in honor of World Breastfeeding Week, I bring you all of our research summaries from 2004-2008 about breastfeeding. Don’t forget that you can find all breastfeeding-related Science & Sensibilityposts (including this archive) by clicking on “breastfeeding” in the tag cloud. Please also check out these other great breastfeeding resources from Lamaze International.

The articles summarized in this archive are listed here. Please click on the extended post to read the summaries.

  1. Study Challenges Conventional Breastfeeding Advice, Suggests Mothers Should Be Semi-Reclined to Nurse More Effectively
    Colson, S. D., Meek, J. H., & Hawdon, J. M. (2008). Optimal positions for the release of primitive neonatal reflexes stimulating breastfeeding. Early Human Development, doi: 10.1016/j.earlhumdev.2007.12.003.
  2. Epidural Use in Labor Appears to Disturb Newborns’ Physiologic Response to Skin-to-skin Contact
    Jonas, W., Wiklund, I., Nissen, E., Ransjo-Arvidson, A. B., & Uvnas-Moberg, K. (2007). Newborn skin temperature two days postpartum during breastfeeding related to different labour ward practices. Early Human Development, 83(1), 55-62.
  3. Updated Cochrane Systematic Review Finds Stronger Evidence of Benefit for Early Skin-to-skin Contact
    Moore, E., Anderson, G., &; Bergman, N. (2007). Early skin-to-skin contact for mothers and their healthy newborn infants. Cochrane Database of Systematic Reviews, (3)(3), CD003519.
  4. Group Prenatal Care Reduces Preterm Birth by One-Third, Improves Breastfeeding Success
    Ickovics, J. R., Kershaw, T. S., Westdahl, C., Magriples, U., Massey, Z., Reynolds, H., et al. (2007). Group prenatal care and perinatal outcomes: A randomized controlled trial. Obstetrics and Gynecology, 110(2), 330-339.
  5. Home Birth and Breastfeeding May Set the Stage for Healthy Immune Systems in Infants
    Penders, J., Thijs, C., Vink, C., Stelma, F. F., Snijders, B., Kummeling, I., et al. (2006). Factors influencing the composition of the intestinal microbiota in early infancy. Pediatrics, 118(2), 511 – 521.
  6. Cochrane Systematic Review Confirms Effectiveness of Breastfeeding for Reducing Procedural Pain in Newborns
    Shah, P. S., Aliwalas, L. L., & Shah, V. (2006). Breastfeeding or breastmilk for procedural pain in neonates. The Cochrane Library, Issue 3.
  7. New Pediatric Growth Charts Reflect Breastfeeding as the Norm
    WHO Multicentre Growth Reference Study Group (2006). “WHO Child Growth Standards.” Acta Paediatrica, Supplement 450.
  8. Longer Duration of Breastfeeding is Associated with Lower Risk of Type 2 Diabetes
    Stuebe, A. M., Rich-Edwards, J. W., Willett, W. C., Manson, J. E., Michels, K. B. (2005). Duration of lactation and incidence of type-2 diabetes. JAMA, 294(20), 2601-10.
  9. Exposure to Smell of Mother’s Milk Reduces Distress During Painful Newborn Procedures
    Rattaz, C., Goubet, N., & Bullinger, A. (2005). The calming effect of a familiar odor on full-term newborns. Journal of Developmental & Behavioral Pediatrics, 26(2), 86-92.
  10. Evidence-Based AAP Policy Emphasizes Link Between Normal Birth and Successful Breastfeeding
    American Academy of Pediatrics. (2005). Breastfeeding and the use of human milk. Pediatrics, 115 (2), 496-506.
  11. Beneficial Effects of Kangaroo Care Are Not Limited to Preterm Newborns
    Ferber, S. G. and Makhoul, I.R. (2004). “The effect of skin-to-skin contact (kangaroo care) shortly after birth on the neurobehavioral responses of the term newborn: a randomized, controlled trial.” Pediatrics. 113 (4): 858-65.

Click on the extended post to read the summaries.

1. Study Challenges Conventional Breastfeeding Advice, Suggests Mothers Should Be Semi-Reclined to Nurse More Effectively
Colson SD, Meek JH, & Hawdon JM (2008). Optimal positions for the release of primitive neonatal reflexes stimulating breastfeeding. Early human development, 84 (7), 441-9 PMID: 18243594

Summary: In this descriptive observational study, researchers videotaped 40 healthy breastfeeding mother-infant pairs in the first month after birth to explore whether maternal posture and infant positioning affect the expression of neonatal reflexes that support effective, pain-free breastfeeding. To be eligible, women must have had low-risk pregnancies and given birth to healthy, term infants with 5-minute Apgar scores of at least 9. Effort was made to recruit an ethnically diverse sample, and data were analyzed according to the gestational maturity of the infant at the time of videotaping.

The researchers divided videotaped feeding episodes into pre-feed, latch, and ingestion and examined each period for instances of any primitive neonatal reflexes, defined as “inborn unconditioned reflex responses, spontaneous behaviours and reactions to endogenous or environmental stimuli developing during foetal life and observed in all normal healthy term neonates at birth” (p. 3).

Examples of these reflexes include hand-to-mouth movements, gaping of the mouth, cycling movements of the arm or leg, and bobbing or nodding of the head. After recording instances of reflexive behavior, the researchers interpreted the type and function of the reflexes and their relationship to effective, pain-free breastfeeding. Maternal and infant postures were characterized by whether they were consistent with “biological nurturing” (BN), a breastfeeding approach in which the mother is encouraged to lean back and the baby is held prone, facing the mother and in contact with her body contours.

Twenty primitive neonatal reflexes were described, which the researchers categorized into four types: endogenous, motor, anti-gravity, and rhythmic. Some of these reflexes seemed to function to find or latch onto the nipple while others supported milk transfer. More primitive neonatal reflexes were observed when women were in full-BN postures (mean=16 reflexes) compared with when women were in partial- or non-BN postures such as sitting upright (mean=12 reflexes).

Some reflexes such as head bobbing, rooting, and hand-to-mouth movements seemed to act as barriers to effective breastfeeding in partial- or non-BN positions while they appeared to stimulate and support breastfeeding in full-BN positions. When mothers who were experiencing breastfeeding problems assumed BN positions, the researchers observed that “gulping and gagging diminished, [and] the baby often became the active agent controlling the feed, aided by the different types of [reflexes]” (p. 5).

This study also suggests that women, too, may have innate behaviors that facilitate those of the infant. In full-BN positioning, women instinctively elicited their infant’s primitive neonatal reflexes in a sequence that promoted effective feeding, behaviors not seen with partial or non-BN positioning. Said an untutored woman in full BN position after spontaneously assisting her baby’s efforts, “Breastfeeding is so easy. I wish more of my friends were doing it” (p. 7).

Significance for Normal Birth:  “Babies are born to breastfeed.” Research demonstrates that, left undisturbed after birth, healthy term newborns perform a sequence of reflexive prefeeding behaviors culminating in self-attachment to the mother’s breast. Despite this normal behavior, many breastfeeding mother-infant pairs encounter feeding problems in the early days and weeks. These problems can cause women to discontinue exclusive breastfeeding earlier than planned.

While the phenomenon of newborn self-attachment is well documented, there is a much smaller body of literature mapping newborn reflexive behaviors to breastfeeding effectiveness after the initial feeding. This study provides evidence that an approach to breastfeeding that proponents have termed “biological nurturing” stimulates reflexive behaviors in newborn and mother alike. These synchronized reflexes seem to support both effective, pain-free latch and ingestion of milk.

In contrast to prevailing advice that breastfeeding mothers should sit upright and support the baby’s back and head, biological nurturing involves semi-reclined positioning with the baby prone and in close contact with the mother’s body. Babies in full-biological nursing positions employ anti-gravity reflexes to locate the breast and latch without dorsal support, and their mothers assist them in that task. Additional research is warranted, but the researchers offer a compelling case that breastfeeding continues to be mediated by newborn reflexive behavior well after birth, that postures and positions may either support or hinder these reflexes, and that by inhibiting or overriding instinctive maternal behaviors, typical breastfeeding instruction may be counterproductive.

2. Epidural Use in Labor Appears to Disturb Newborns’ Physiologic Response to Skin-to-skin Contact
Jonas W, Wiklund I, Nissen E, Ransjö-Arvidson AB, & Uvnäs-Moberg K (2007). Newborn skin temperature two days postpartum during breastfeeding related to different labour ward practices.Early human development, 83 (1), 55-62 PMID: 16879936

Summary: In this prospective observational study, researchers examined the normal physiologic skin temperature patterns in breastfeeding newborns held skin-to-skin two days after birth and compared findings in babies whose mothers had received epidural analgesia and oxytocin in labor or oxytocin alone with those whose mothers were not exposed to either intervention. First-time mothers giving birth on a weekday to healthy, full-term, singleton infants with a 1-minute Apgar score of at least 8 were recruited and remained eligible if they were not separated from their babies after the birth and the babies were exclusively breastfed. The study took place in Sweden, where usual care includes immediate and prolonged skin-to-skin contact after the birth and rooming-in. At the maternity hospital where the study was conducted, sufentanil (an opioid that crosses the placenta) was included in the epidural preparation. In total, 47 mother-infant pairs participated in the study, 9 of whom underwent oxytocin augmentation (oxytocin group), 20 of whom had received both epidural analgesia and oxytocin in labor (epidural group), and 18 of whom had neither intervention (control group). Clinical characteristics across the three groups were similar except with respect to the use of nitrous oxide, which was more common in the epidural group.

On the second postpartum day, after exhibiting signs of hunger (e.g., rooting), each infant was undressed, weighed, placed skin-to-skin on the mother, and covered with a light blanket. The researchers documented interscapular (between the shoulder blades) temperatures immediately after the mother and infant established skin-to-skin contact, and at 5, 10, 20, and 30 minutes after the first reading. They also documented the time of onset and duration of breastfeeding as well as the environmental temperature in the maternity rooms. The temperature at the moment breastfeeding began was not documented, so the interval reading preceding onset of suckling was used as a proxy.

At the moment skin-to-skin contact commenced, babies in the epidural group had significantly higher temperatures than those in the control group. Epidural-exposed babies also exhibited a significant negative correlation between their age (in hours) and their temperature, such that the younger the baby, the higher the temperature at the first reading. This finding correlates with the well-documented finding that epidural analgesia raises maternal and newborn temperatures. In both the control group and the oxytocin group, temperatures rose significantly over the first 10 minutes of skin-to-skin contact and then remained stable, with the plateau level among control group babies slightly lower than that exhibited by oxytocin-exposed babies (35 vs 36 degrees Celsius). In contrast, temperatures in the epidural-exposed babies decreased significantly during the first 10 minutes, and then remained relatively stable around 34.5 degrees Celsius. In the control group, the temperature rise occurred after the onset of suckling and continued beyond five minutes. In contrast, temperatures rose in the oxytocin group immediately upon skin-to-skin contact and did not continue to rise after several minutes of suckling. In the epidural group, no temperature rise was noted after the onset of suckling.

Significance for Normal Birth: This small study does not provide strong evidence of any particular harm from epidurals or oxytocin augmentation. Rather, it serves as a cautionary tale of the wide-ranging and unpredictable disturbances caused by intervening in the normal process. For the first time, researchers have demonstrated the normal temperature patterns in babies on the second day of life who have not been separated from their mothers and who are held skin-to-skin. They have further demonstrated that interventions that took place in labor are associated with disturbances in this normal physiologic response many hours later. The complex hormonal changes that occur during skin-to-skin contact in the postpartum period are just beginning to be understood. However, evidence suggests that these hormonal shifts modulate newborns’ feeding and bonding behavior, temperature stability, and how much they cry as well as the mother’s mood. It is possible that some babies will not be able to reap the full benefits of skin-to-skin contact if they are not able to respond to this stimulus as nature intended. More research is needed to determine the clinical significance of the temperature pattern disturbances observed in this study. Given the evidence that epidurals containing fentanyl (a drug closely related to sufentanil) increase the risk of early breastfeeding cessation (Beilin, Bodian, Weiser, Hossain, Arnold, Feierman, et al., 2005), it is possible that such disturbances represent a pathway by which that labor interventions may impact newborn feeding behavior.

References
Beilin, Y., Bodian, C. A., Weiser, J., Hossain, S., Arnold, I., Feierman, D. E., et al. (2005). Effect of labor epidural analgesia with and without fentanyl on infant breast-feeding: A prospective, randomized, double-blind study. Anesthesiology, 103(6), 1211-1217

3. Updated Cochrane Systematic Review Finds Stronger Evidence of Benefit for Early Skin-to-skin Contact
Moore ER, Anderson GC, & Bergman N (2007). Early skin-to-skin contact for mothers and their healthy newborn infants. Cochrane database of systematic reviews (Online) (3) PMID: 17636727

Summary: In this systematic review, researchers evaluated the effects of early skin-to-skin contact (SSC) between the mothers and healthy newborns on breastfeeding, behavior, and physiologic adaptation. The review was restricted to mothers and their healthy full term (>37 weeks) or late-preterm (34-37 weeks) babies and only trials where SSC commenced within the first 24 hours were included. This Cochrane review updates a 2003 review with data from trials published since that time.

Thirty trials involving 1925 mother-baby pairs were included, about twice as many as were included in the 2003 review. SSC was found to have a statistically significant effect on breastfeeding initiation, duration, and exclusivity. Infants who were held skin-to-skin were more than twice as likely to breastfeed successfully during their first feed, established effective breastfeeding sooner, were more likely to be breastfeeding at 1-4 months of age, and breastfed longer. Babies who underwent SSC were also more likely to maintain temperatures in the neutral thermal range (neither too cold nor too hot) and showed less variability in their temperatures. Infants exposed to SSC had blood glucose levels that were higher than those in the control groups by an average of nearly 11 mg/dl, which is highly clinically significant. A large difference, favoring SSC, was also found in infant crying. Late preterm babies undergoing SSC demonstrated better cardio-pulmonary and metabolic stabilization compared with similar babies placed in incubators. No statistically significant differences were found in other outcomes such as admission to the neonatal ICU or infant weight loss. The review yielded no evidence of any harm from SSC in term or healthy preterm babies.

Mothers who underwent SSC displayed more affectionate behavior toward their babies, such as kissing, smiling and holding and scored better on measures of maternal attachment in the first few days after birth. Some included studies found statistically significant differences in these behaviors persisting as long as one year. The reviewers did not identify any evidence that SSC was harmful to mothers. Studies that measured women’s satisfaction with their care found increased satisfaction with SSC.

Significance for Normal Birth: Separation of mothers from their babies after birth does not occur in any mammals other than humans and has only occurred in humans during the last century. In order for a mammalian species to survive, newborns must learn to nurse and their mothers must learn to protect and care for them. Researchers have described a “sensitive period” in the first hour after birth where hormonal changes and innate behaviors coincide to produce optimal outcomes. They have also have identified care practices that disrupt these processes with detrimental effects. Even apparently benign practices such as weighing, bathing or swaddling babies can disrupt their innate behaviors if they occur in the first 1-2 hours after birth (1, 2).

This review provides incontrovertible evidence that denying skin-to-skin contact between healthy babies and their mothers after birth is harmful. Although the Cochrane systematic review published in 2003 provided strong evidence that SSC is beneficial, in this update researchers reviewed a much larger body of research with findings related to many more clinical and psychosocial outcomes. They also gave special attention to the effects of skin-to-skin contact on babies born between 34-36 weeks of gestation, a population that unfortunately represents a growing proportion of newborns and who are at increased risk for morbidity and mortality (3). With such compelling evidence, it is unethical to continue to deny healthy babies and their mothers skin-to-skin contact after birth. The principles of beneficence (doing good) and nonmaleficence (avoiding doing harm) demand that uninterrupted time for mothers and babies after birth take priority over labor ward routines intended for staff convenience and hospital efficiency and that postpartum and newborn interventions either be delayed or, when necessary, be carried out with the baby and mother skin-to-skin.

References

1. Jansson, U. M., Mustafa, T., Khan, M. A., Lindblad, B. S., & Widstrom, A. M. (1995). The effects of medically-orientated labour ward routines on prefeeding behaviour and body temperature in newborn infants. Journal of Tropical Medicine, 41(6), 360-363.

2. Righard, L., & Alade, M. O. (1990). Effect of delivery room routines on success of first breast-feed. Lancet, 336(8723), 1105-1107.

3. March of Dimes. (2006). Late preterm birth: Every week matters. Retrieved August 15, 2007, from www.marchofdimes.com/files/MP_Late_Preterm_Birth-Every_Week_Matters_3-24-06.pdf.

4. Group Prenatal Care Reduces Preterm Birth by One-Third, Improves Breastfeeding Success
Ickovics JR, Kershaw TS, Westdahl C, Magriples U, Massey Z, Reynolds H, & Rising SS (2007). Group prenatal care and perinatal outcomes: a randomized controlled trial. Obstetrics and gynecology, 110 (2 Pt 1), 330-9 PMID: 17666608

Summary: In this multi-center randomized, controlled trial, investigators evaluated the effect of the CenteringPregnancy model of group prenatal care on perinatal outcomes, including preterm birth, birth weight, psychosocial outcomes, breastfeeding success, women’s satisfaction, and health care costs. Eligible women were randomized to group prenatal care (intervention group, n=653) or traditional care (control group, n=394). All women attended their first prenatal visit in the traditional one-to-one setting. For their subsequent care, women in the intervention group attended 10 prenatal sessions with approximately 7 other pregnant women due in the same month. The facilitating obstetrician or midwife had a brief one-to-one encounter with each pregnant woman in the group space to evaluate fetal and maternal wellbeing and address individual concerns. While they waited for their individual assessments, women conducted self-care activities such as weight checks and blood pressure monitoring and recorded the results in their own charts. The remainder of the 2-hour sessions was dedicated to facilitated group discussion and education based on CenteringPregnancy program materials and client self assessments. Women in the control group continued to attend prenatal visits at the clinic according to the traditional schedule or as otherwise clinically indicated. In the settings where the trial took place, traditional prenatal visits lasted about 10-15 minutes each for a total of 2 hours of prenatal care over the course of a woman’s pregnancy. The group care model, on the other hand, yielded about 20 hours of prenatal care over the course of the pregnancy.

After controlling for confounding factors, women assigned to group prenatal care were 33% less likely to give birth preterm (10% in the intervention group versus 14% among controls). When the investigators limited the analysis to African American women, who represented 80% of all participants, the protective effect of the group care model was even stronger – there was a 10% preterm birth rate in the intervention group compared with 16% of controls, for a 41% reduction in risk. Statistical analysis revealed that the group model was most effective at preventing late preterm births (35-37 weeks), however a significant reduction in risk of preterm birth was observed at every week of gestation from 26 weeks forward. Although there was no significant difference in the overall risk of low birth weight (defined as less than 2,500 g), the researchers demonstrated a statistically significant “dose response” effect, where increased exposure to the group care model resulted in both longer gestation and higher birth weight.

Women randomized to the group care model were also more likely to initiate breastfeeding (67% versus 55%). They also scored significantly better on a pregnancy knowledge questionnaire, reported increased readiness for labor and birth, and were more satisfied with their prenatal care. There were no statistically significant differences in other clinical and psychosocial outcomes measured. Costs were similar across both models of prenatal care.

Significance for Normal Birth: That CenteringPregnancy’s effect on preterm birth has not been matched by any medical or technological intervention reinforces an important lesson about what is good for mothers and babies. It is not surprising that care that builds women’s confidence, mitigates stress, and teaches wellness and self-care would yield psychosocial benefits. What a medicalized view of pregnancy and birth too often fails to recognize, however, is that these same elements contribute to optimal clinical outcomes as well. In pregnancy, as in birth, an approach that values medical intervention and constant technological surveillance for problems is unlikely to be effective at enhancing an essentially healthy process. In pregnancy, as in birth, building a circle of support for an expectant mother enhances her ability to care for herself and her baby and cope with unfamiliar but normal emotional and physical changes. Caring for women holistically is not just “nice” it is good medicine.

Pregnancy is a normal physiologic state, though vulnerable to disruptions from chronic or acute stress, unhealthy behaviors such as smoking, and harmful conditions such as malnutrition or violence in the home. In the current prevailing model of prenatal care, visits are brief and counseling for nutrition, smoking cessation, and domestic violence concerns are often provided separately, contributing to fragmentation of care and creating unnecessary barriers to access. CenteringPregnancy, like all mother-friendly care, does not demand that the woman accommodate institutional routines and navigate complex systems but arranges care around her needs instead. This study reveals a forgotten outcome of putting the woman at the center and constructing a supportive environment around her: babies benefit, too.

5. Home Birth and Breastfeeding May Set the Stage for Healthy Immune Systems in Infants
Penders J, Thijs C, Vink C, Stelma FF, Snijders B, Kummeling I, van den Brandt PA, & Stobberingh EE (2006). Factors influencing the composition of the intestinal microbiota in early infancy. Pediatrics, 118 (2), 511-21 PMID: 16882802

Summary: In this prospective cohort study, researchers examined the influence of several factors on the microbial environment of infants’ gastrointestinal tracts. Fecal samples from 1,032 infants between 3 and 6 weeks of age were collected by the parents and presence and quantity of various “beneficial” (e.g., bifidobacteria and lactobacilli) and “harmful” (e.g., C. difficile, E. coli, and B. fragilis) species of microbes were determined by polymerase chain-reaction tests. The study took place in the Netherlands where home birth and exclusive breastfeeding are common. In this study, 47.5% of the infants were born vaginally at home (n = 480), and 70% were exclusively breastfed during the first month of life (n = 700). The cesarean-section rate was 10.7% (n = 108).

After adjusting for confounding factors, infants born by cesarean section had a significantly higher rate of colonization with C. difficile and lower rates of colonization with bifidobacteria and B. fragilis than those born vaginally at home. Each day of hospitalization after birth was associated with a 13% increase in the rate of colonization with C. difficile. Exclusively breastfed infants were significantly less likely than formula-fed babies to be colonized with E. coli, C. difficile, B. fragilis, and lactobacilli. Term infants born at home and breastfed exclusively had the highest numbers of bifidobacteria and the lowest numbers of C. difficile and E. coli compared with any other group of infants.

Significance for Normal Birth: The newborn’s gut, sterile at birth, rapidly becomes colonized with millions of microbes. The number and type of gut flora have been shown to influence immune system development, the risk of allergies and asthma, and metabolic functions such as the production of vitamin K.

In normal vaginal birth, newborns encounter their own mother’s microbes during the critical first hours. Some of these microbes are beneficial and promote healthy gastrointenstinal development. Other microbes are pathologic (may cause disease), but maternal antibodies, passed to the baby via breastfeeding, help ensure that the baby tolerates their presence. When a baby is born by cesarean surgery and/or subjected to prolonged hospitalization, unfamiliar hospital-borne pathogens such as C. difficile dominate the microbial environment of the newborn’s gut. Minimizing the baby’s contact with these harmful organisms by avoiding hospitalization for normal birth while maximizing newborn’s exposure to antibodies and beneficial microbes by promoting exclusive breastfeeding may decrease the likelihood of newborn infection and optimize the baby’s developing immune system for lifelong health benefits.

6. Cochrane Systematic Review Confirms Effectiveness of Breastfeeding for Reducing Procedural Pain in Newborns
Shah PS, Aliwalas LI, & Shah V (2006). Breastfeeding or breast milk for procedural pain in neonates. Cochrane database of systematic reviews (Online), 3 PMID: 16856069

Summary: This systematic review by the Cochrane Collaboration evaluated the effectiveness of breastfeeding or supplemental breast milk on pain in newborns undergoing painful procedures. The researchers extracted data from 11 studies that met predetermined eligibility criteria for inclusion in the review. All of the studies compared the effect of breastfeeding or supplemental breast milk versus a control intervention on pain in newborns during a single procedure (heel lance or venipuncture). Pain was determined by physiologic (heart rate, respiratory rate, etc.) and/or behavioral (cry, facial actions) indicators. In some cases, validated composite pain scores were used. Both term (> 37 weeks) and preterm (< 37 weeks) babies were included in the review.

For all indicators studied, breastfed infants demonstrated less pain or no significant difference compared with infants who were swaddled, provided a pacifier, positioned in the mother’s arms, or given glucose. Babies who were provided supplemental breast milk also demonstrated better or equivalent pain tolerance compared with babies who received other interventions, with one exception: Babies given glucose/sucrose had significantly lower increases in heart rate and duration of crying versus babies fed supplemental breast milk.

Significance for Normal Birth: A well-designed systematic review represents the gold standard of evidence. In this case, strong evidence emphasizes the role of breastfeeding in alleviating pain in newborns undergoing venipuncture or heel-stick procedures. Whether the mechanism of pain relief is the comfort of being close to the mother, the sweetness of her milk, the hormonal composition of breast milk, or a combination of these factors remains to be determined.

Although many different interventions were compared with breastfeeding in the 11 studies included in this review, breastfeeding was consistently beneficial. The evidence is compelling enough to command a change in the practices of all birth settings where infants are denied breastfeeding during painful procedures. Nonseparation of mothers and infants and unlimited opportunities to breastfeed in the newborn period are the culmination of normal birth and optimize mother-infant bonding and the breastfeeding relationship. When painful procedures are necessary, these care practices also optimize pain relief, potentially decreasing trauma to the newborn and reducing anxiety in the mother.

7. New Pediatric Growth Charts Reflect Breastfeeding as the Norm
WHO Multicentre Growth Reference Study Group (2006). WHO Child Growth Standards based on length/height, weight and age. Acta paediatrica (Oslo, Norway : 1992). Supplement, 450, 76-85 PMID: 16817681 [Full Text]

Summary: The first of a series of new pediatric growth charts have been released by the World Health Organization (WHO). The new growth standards were developed to replace existing pediatric growth charts based on growth patterns in predominantly formula-fed populations. Beginning almost a decade ago, the WHO undertook a detailed and elaborate statistical study, sampling thousands of infants from eight ethnically diverse, economically stable nations where at least 20% of women had access to breastfeeding support and followed WHO infant feeding guidelines. The healthy, term infants who participated were followed by trained researchers biweekly for 2 months, monthly up to 12 months, and bimonthly up to 24 months. An additional sample of children was followed up to 71 months. Breastfeeding support was provided as needed. Data were collected on infant growth patterns and achievement of motor skills.

The resulting infant growth standards offer pediatric providers and parents the first evidence-based information on how children should grow under optimal conditions. The researchers found that there was very little ethnic variability in average growth or achievement of motor skills, suggesting that poverty and sub-optimal nutrition are responsible for previously observed regional variability in infant growth.

Significance for Normal Birth: The WHO infant growth charts are an important step in positioning breastfeeding as the norm and reversing decades of erroneous advice to parents of breastfed infants who were told that their infants were failing to thrive because they gained weight more slowly than formula fed infants. Now, more formula fed babies will be seen to “fall off the curve” by gaining weight too rapidly, an important predictor of childhood obesity.

The results of the WHO Multicentre Growth Reference Study provide solid evidence that breastfeeding contributes to the optimal growth and motor development of infants. Interventions in normal birth, including cesarean surgery and unnecessary separation of mothers and babies impede women’s ability to initiate successful breastfeeding with their newborns thereby contributing to less than optimal infant growth and development.

8. Longer Duration of Breastfeeding is Associated with Lower Risk of Type 2 Diabetes
Stuebe, A. (2005). Duration of Lactation and Incidence of Type 2 Diabetes JAMA: The Journal of the American Medical Association, 294 (20), 2601-2610 DOI: 10.1001/jama.294.20.2601

Summary: In this analysis of two large observational study cohorts, researchers evaluated the impact of duration of breastfeeding on the likelihood of developing type-2 diabetes later in life. A total of 83,585 parous women in the Nurses Health Study (NHS) cohort and 73,418 in the Nurses Health Study-II (NHS-II) cohort reported lactation history. Data on body-mass index (BMI), diet, exercise, smoking status, history of gestational diabetes, and other risk factors were also collected and multiple analyses were conducted to determine and control for the influence of these potential confounders.

Among women who had given birth within the previous 15 years, the risk of developing type-2 diabetes was decreased by 15% for each year of lactation in the NHS cohort and 14% in the NHS-II cohort, after controlling for diabetes risk factors. The association was much more modest in women who had given birth more than 15 years previously, and no association was observed among postmenopausal women. No decreased risk was observed in women with a history of gestational diabetes, who are at markedly higher risk of developing type-2 diabetes later in life.

Duration of exclusive (versus total) breastfeeding was even more strongly associated with decreased risk, as was longer duration of breastfeeding per pregnancy. For instance, 1 year of lactation for 1 child resulted in a 44% reduction in age-adjusted risk, whereas 1 year of lactation between 2 children resulting in a 24% reduction in age-adjusted risk. The researchers also found evidence that the beneficial association begins to develop after 6 months of lactation. Use of medications to artificially suppress lactation was associated with a 46% increase in the risk of developing type-2 diabetes.

Significance for Normal Birth: Breastfeeding is the natural culmination of a normal birth and is associated with a long list of health benefits for both the baby and the mother. Evidence suggests that many of the care practices that undermine normal birth also undermine women’s ability to successfully initiate exclusive breastfeeding (Kroeger, 2004). This study points to a novel long-term effect of interrupting the breastfeeding relationship. Type-2 diabetes is associated with many adverse health outcomes, poor quality of life, and a rapidly growing burden on the health care system. Working to help women initiate and continue breastfeeding, with exclusive breastfeeding for at least the first six months, may help prevent or delay the onset of type-2 diabetes. Furthermore, prevention of diabetes may be a powerful incentive for women to choose breastfeeding and to continue breastfeeding beyond the child’s infancy.

Reference
Kroeger, M. (2004) The impact of birthing practices on breastfeeding: protecting the mother and baby continuum. Jones and Bartlett, Sudbury, MA.

9. Exposure to Smell of Mother’s Milk Reduces Distress During Painful Newborn Procedures
Rattaz C, Goubet N, & Bullinger A (2005). The calming effect of a familiar odor on full-term newborns. Journal of developmental and behavioral pediatrics : JDBP, 26 (2), 86-92 PMID:15827459

Summary: In this randomized controlled trial (RCT), researchers evaluated the effect of exposure to familiar odors on newborns experiencing painful procedures. Forty-four healthy, full-term, exclusively-breastfed newborns underwent routine heel-stick blood sampling at 3 days of age. Eleven were exposed to a sample of their mother’s milk during the procedure, 11 were exposed to a vanilla scent to which they had been familiarized over the previous 24 hours, 11 were exposed to a vanilla scent to which they had not previously been exposed and a control group of 11 were exposed to no scent during the procedure.

Babies smelling a familiar odor (either maternal milk or vanilla) cried and grimaced significantly less during the period immediately following the heel-stick than those smelling an unfamiliar odor or no odor at all. Both groups of babies smelling a familiar odor reduced crying between the heel-stick and the recovery period, demonstrating that they settled themselves more easily. Infants smelling their mother’s milk displayed fewer head movements (a measure of motor agitation or stress) during the heel-stick. No other significant differences were found between the group smelling maternal milk and that smelling familiar vanilla nor between the groups smelling a familiar odor and the group smelling an unfamiliar odor or no odor at all. No differences were found between the babies smelling an unfamiliar odor and those smelling no odor.

Significance for Normal Birth: Research has shown that it is best for mothers and babies to stay together after birth. Unfortunately, in many hospitals separation of the mother and her baby takes place routinely, and these separations often occur to accommodate painful or stressful procedures such as blood draws, administration of medications or circumcision. Previous research has found that close contact and/or breastfeeding during painful procedures provides significant analgesia (pain relief) for the newborn. This study suggests that the newborn’s keen inborn sense of smell contributes to the analgesic effect. It provides further evidence that newborns are physiologically designed to feel secure and comforted when they are in close contact with their mothers.

10. Evidence-Based AAP Policy Emphasizes Link Between Normal Birth and Successful Breastfeeding
Gartner LM, Morton J, Lawrence RA, Naylor AJ, O’Hare D, Schanler RJ, Eidelman AI, & American Academy of Pediatrics Section on Breastfeeding (2005). Breastfeeding and the use of human milk. Pediatrics, 115 (2), 496-506 PMID: 15687461 [Full Text]

Summary: This policy statement, prepared by the American Academy of Pediatrics Section on Breastfeeding, provides evidence-based information to help pediatric health care professionals promote, protect and support breastfeeding. It replaces the 1997 AAP policy statement, providing an update of the literature on the benefits of human milk and recommendations for the promotion and clinical management of breastfeeding for both healthy term infants and high-risk infants.

The AAP’s recommendations reflect a strong stance in favor of normal birth. Routine or unnecessary use of interventions that have been shown to interfere with breastfeeding, such as suctioning of the infant’s nose and mouth, are discouraged. The authors recommend minimizing the use of maternal medications that affect feeding behavior. They also advise delaying newborn routines such as the first bath and administration of medications until after the first successful feeding, with skin-to-skin contact maintained from the time of birth whenever possible.

Significance for Normal Birth: The new policy statement definitively positions exclusive breastfeeding as the “normative model against which all alternative feeding methods must be measured.” (p. 496). Similarly, normal birth should be the reference model for maternity care, with interventions and deviations only occurring with sound medical rationale and after consideration of potential risks and adverse outcomes. When birth and breastfeeding are seen as a continuum, it is easier to understand how promoting normalcy in maternity care improves the likelihood of successful lactation. Conversely, care practices that disturb the normal physiologic events of labor and birth may have the effect of disrupting the breastfeeding relationship.

This revised policy statement from the American Academy of Pediatrics, which cites more than 200 scientific articles, is an important evidence-based resource for all maternity care professionals, as well as those working exclusively with pediatric populations.

11. Beneficial Effects of Kangaroo Care Are Not Limited to Preterm Newborns
Ferber SG, & Makhoul IR (2004). The effect of skin-to-skin contact (kangaroo care) shortly after birth on the neurobehavioral responses of the term newborn: a randomized, controlled trial.Pediatrics, 113 (4), 858-65 PMID: 15060238

Summary: This randomized controlled trial compared the self-regulation and neurobehavioral patterns of term newborns who received “kangaroo-care” (prolonged skin-to-skin contact) soon after birth with those of term newborns who were separated from their mothers after birth. Immediate postnatal care was identical in both groups and involved being dried placed on the mother’s chest for 5-10 minutes then being removed from the delivery room to be weighed and dressed. Newborns in the experimental group (n=25) were returned to the delivery room where they were undressed and placed between their mothers’ breasts with a blanket over their backs for an additional hour. Control group infants (n=22) remained in the nursery during the first hour of the mother’s postpartum recovery. A 60-minute behavioral observation was conducted four hours after delivery. During the observation, researchers measured neurobehavioral adaptation using standard definitions and instruments previously described in the relevant literature.

Infants who received kangaroo care spent significantly more time in sleep states, especially in quiet sleep, and less time in transitional, fussy, crying, or alert states, than infants who were separated from their mothers. Infants in the experimental group also exhibited more motor control, evidenced by more flexed and fewer extended movements. Other elements of neurobehavioral adaptation were studied, but no statistically significant differences were found in these characteristics. The results indicate that kangaroo care may be beneficial in helping term infants self-regulate with respect to motor systems balance and sleep organization during the transition out of the womb. The authors conclude that healthy term infants who receive kangaroo care shortly after birth may be better equipped to make “biologically cost-effective use of internal resources.”

Significance for Normal Birth: This study shows that hospital routines that separate mother and baby have an adverse effect on normal newborn adaptation to extrauterine life. Even after a normal labor and birth, the newborn has many complex tasks to undertake in order to make a smooth transition out of the womb and remain healthy. Extended skin-to-skin contact is the healthy norm among mammals. This study provides evidence that this “intervention” helps babies minimize time and energy spent regulating sleep states and motor activity, potentially freeing internal resources for use in regulating other essential systems such as the cardiovascular and respiratory systems.

While there is copious research that supports the use of kangaroo care for preterm infants, this is one of the few studies that address the effects of kangaroo care for the healthy term infant. The study was conducted in an institution in northern Israel where the standard postpartum routine calls for extended separation of mother and baby with no opportunity to feed the baby (at the breast or with formula) before six hours of life. It is likely that neurobehavioral adaptations could be further enhanced if the mother-infant pairs were provided unlimited opportunity to breastfeed in addition to extended skin-to-skin contact.

5 Comments

From the Research Summaries Archives: Breastfeeding

August 1, 2009 07:00 AM by Jill Arnold
This is awesome. I will read it later while NAK. (nursing at keyboard)

From the Research Summaries Archives: Breastfeeding

August 1, 2009 07:00 AM by Amy M. Romano, RN,CNM
Well, that seems appropriate! :)

From the Research Summaries Archives: Breastfeeding

August 2, 2009 07:00 AM by World Breastfeeding Week « Woman to Woman Childbirth Education
[...] Science and Sensibility blog has research summaries about breastfeeding for 2004-2008. It’s lengthy, so I’ll just let you go read over there. It’s very [...]

From the Research Summaries Archives: Breastfeeding

August 3, 2009 07:00 AM by Reality Rounds
Amy, Great articles. I am always interested in the SSC right after birth. You, like me, have probably witnessed hospital births where the staff treat the birth of a baby like a five alarm fire. It drives me crazy! Nurses yell "We need a baby nurse!" like they need a policeman. Promoting SSC at birth would help reduce some of this crazy anxiety some L&D nurses have about the immediate care of a newborn. "As God as my witness I will change this practice at my hospital" Nurse Scarlett O'Harried.

From the Research Summaries Archives: Breastfeeding

April 7, 2010 07:00 AM by Ann H. Shopoff, BSN, CD(DONA)
The study on kangaroo care seemed slightly flawed to me in that there was no group where babies remained with the mother, but wrapped in a blanket (which is the standard in our area). This begs the question -- was it the skin-to-skin contact or the remaining in the mother's arms that made the difference.

To leave a comment, click on the Comment icon on the left side of the screen.  You must login to submit a comment.  

Recent Stories
Research Review: Waterbirth Continues to be an Appropriate Option for Low-Risk Families

Series: Building Your Birth Business - Five Reasons to Consider an Early Pregnancy Class

Causal Inference - A Better Research Method for Studying Labor & Birth?