This section covers a range of recent studies related to feeding, relationship building and infant health.
January – March 2019 research round up
Infant Feeding expert and blogger Analytical Armadillo has produced a round up of 45 infant feeding-related studies, published between January and March 2019. Ranging from a meta-analysis of the effects of kangaroo care on preterm infants, to racial inequalities in breastfeeding, the document provides a concise summary of each study.
Stroking modulates noxious-evoked brain activity in human infants
This study of 32 infants explored whether touch can reduce noxious-evoked brain activity, following previous studies of adults showing that touch of C fibre sensory neurons is pleasant and can reduce pain perception. Researchers found that stroking prior to an experimental noxious stimulus or clinical heel lance can attenuate noxious-evoked brain activity in infants. They conclude that C-tactile fibres may represent a biological target for non-pharmacological interventions that modulate pain in early life, and said that further research is needed to ascertain whether this simple tactile intervention is effective in modulating pain in the context of other clinical procedures and in preterm infants.
Comparison of breast milk compositions among mothers delivering small-for-gestational age, appropriate-for-gestational age, and large-for-gestational age infants
This study of 75 milk samples found that the carbohydrate (CHO) composition of breastmilk in mothers of infants who were small-for-gestational age (SGA) was significantly lower than that in mothers of appropriate-for-gestational age (AGA) infants – but this was not found to have any clinical significance. In addition, no significant correlation was found between maternal BMI, gestational age, and CHO.
Phattraprayoon, N, Kraisonsin, N, and Kanjanapattanakul, W, (2018). Comparison of breast milk compositions among mothers delivering small-for-gestational age, appropriate-for-gestational age, and large-for-gestational age infants. Breastfeeding Medicine, doi.org/10.1089/bfm.2018.0043
Domperidone increases breast milk production in mothers of premature babies
This systematic review of five randomised controlled trials found that domperidone increased mean daily expressed milk volume by 88ml/day amongst women feeding expressed breastmilk to their premature babies. Further studies are needed to explore this and examine any other possible side effects.
Cup feeding versus other forms of supplemental enteral feeding for newborn infants unable to fully breastfeed
This review of studies on different methods of supplemental enteral feeding found mixed results around the impact of cup feeding. As the majority of infants in the included studies were preterm infants, no recommendations could be made for cup feeding term infants due to the lack of evidence in this population. From the studies of preterm infants, cup feeding may have some benefits for late preterm infants and on breastfeeding rates up to six months of age. Self-reported breastfeeding status and compliance to supplemental interventions may over-report exclusivity and compliance, as societal expectations of breastfeeding and not wishing to disappoint healthcare professionals may influence responses at interview and on questionnaires.
Flint, A, et al. Cup feeding versus other forms of supplemental enteral feeding for newborn infants unable to fully breastfeed. Cochrane Database of Systematic Reviews 2016, Issue 8. Art. No.: CD005092. DOI: 10.1002/14651858.CD005092.pub3
A review of adverse reactions in infants from medications in breastmilk
This article reviewed the literature on adverse drug reactions in infants since a previous review in 2002. 53 case reports and 16 studies of adverse drug reactions in breastfed infants whose mothers were taking a prescribed or over-the-counter medication were selected. Serious acute adverse drug reactions from drugs in breastmilk appear to be uncommon. Infants under 2 months of age, and especially those under 1 month, appear to be most susceptible. Similar to previous reviews, free iodine, opioids, and the use of multiple central nervous system drugs simultaneously were identified as drugs of concern.
Breastfeeding and reduced risk of liver disease in adolescence
This study examined the influence of maternal factors and infant nutrition on the risk of developing non-alcoholic fatty liver disease (NAFLD) in adolescence. Researchers found that normal range BMI at the start of pregnancy and exclusive breast milk feeding for at least the first 6 months of life may reduce the odds of NAFLD in adolescent offspring by half and one third respectively.
Nutrient and food intakes in early life and risk of childhood fractures
In this systematic review of 18 original peer-reviewed articles, the authors identified a limited number of studies whose findings suggest that some nutritional factors, in particular milk avoidance, high cheese intake, high sugar-sweetened beverage intake, high energy intake, or no breastfeeding, may be associated with an increased risk of paediatric fractures.
Handel, M.N., Heitmann, B.L. & Abrahamsen, B. (2015). Nutrient and food intakes in early life and risk of childhood fractures: a systematic review and meta-analysis. American Journal of Clinical Nutrition, doi: 10.3945/ajcn.115.108456
Breastfeeding and Risk of Rheumatoid Arthritis
This meta-analysis suggests that breastfeeding is associated with a lower risk of RA, whether breastfeeding duration is longer or shorter than 12 months.
Breastfeeding by mothers carrying the Hepatitis B virus
A systematic review of prospective studies to confirm the role of breastfeeding in mother-to-child transmission of hepatitis B virus has concluded that, after proper immunoprophylaxis, breastfeeding does not contribute to mother to child transmission of Hepatitis B. A total of 10 studies involving 751 breastfeeding infants and 873 non-breastfeeding infants were included.
Zhongjie Shi, MD; Yuebo Yang, MD; Hao Wang, MD; Lin Ma, MD; Ann Schreiber, BSN; Xiaomao Li, MD; Wenjing Sun, MD; Xuan Zhao, RN; Xu Yang, MD; Liran Zhang, MD; Wenli Lu, MD; Jin Teng, MD; Yufang An, MD. Breastfeeding of Newborns by Mothers Carrying Hepatitis B Virus. Arch Pediatr Adolesc Med. Published online May 2, 2011. doi:10.1001/archpediatrics.2011.72
Two studies explore impact of dummy use on breastfeeding
A multicentre, randomized controlled trial (1) recruited 1,021 mothers who were highly motivated to breastfeed, planned to exclusively breastfeed for three months and whose newborns regained birth weight by 15 days, and assigned them either to offer or not to offer pacifiers.
At three months, 85.8% infants in the pacifier group and 86.2% in the no pacifier group were exclusively breastfeeding. Furthermore, the recommendation to offer a pacifier did not produce a significant decrease in the frequency of exclusive and any breastfeeding at different ages or in the duration of lactation. The researchers conclude that in this group of mothers who were highly motivated to breastfeed and had no breastfeeding difficulties, the recommendation to offer a pacifier at 15 days did not affect the prevalence and duration of breastfeeding.
Another study was carried out in Denmark (2) to investigate how breastfeeding technique and pacifier use were related to breastfeeding problems and duration of breastfeeding. Trained health visitors followed up 570 mothers for six months after childbirth, providing breastfeeding guidance. Mothers also self-reported breastfeeding problems and dummy use using a standard questionnaire.
The researchers found that one half of the mothers showed ineffective breastfeeding technique at the first observation which was significantly associated with mothers reporting early breastfeeding problems, which thereby influenced the breastfeeding duration. Pacifier use had an independent negative impact on duration of breastfeeding, rather than being associated with the presence of breastfeeding problems. Therefore the researchers conclude that use of a pacifier should be avoided in the first weeks after birth.
It is interesting that the first study looked at a population of mothers who were committed to breastfeed for a prolonged period – a situation which is less likely here in the UK. Baby Friendly recommends that breastfeeding mothers should be discouraged from using teats and dummies while their babies are learning to breastfeed, with the reasons for this explained to them. In the community, mothers should be advised additionally of the potential for dummy use to artificially space feeds, with possible detrimental effects on lactation.
- Jenik AG, Vain NE, Gorestein AN, Jacobi NE, for the Pacifier and Breastfeeding Trial Group. Does the recommendation to use a pacifier influence the prevalence of breastfeeding? Journal of Pediatrics 2009;155(3):350–4.
- Kramer MS, Barr RG, Dagenais S, Yang H, Jones P, Ciofani L, et al. Pacifier use, early weaning, and cry/fuss behavior: a randomized controlled trial. JAMA 2001;286(3):322–6.
See also: Jaafar SH, Jahanfar S, Angolkar M, et al. (2011) Pacifier use versus no pacifier use in breastfeeding term infants for increasing duration of breastfeeding (Review). The Cochrane Collaboration.
Breastfeeding reduces the risk of fever after immunisation
A prospective cohort study was conducted in Italy to investigate the effects of breastfeeding on the risk for fever after routine immunisations in 460 infants. The researchers found that fever was reported for 30 (25%), 48 (31%), and 94 (53%) of the infants who were being exclusively breastfed, partially breastfed, or not breastfed at all, respectively (P < .01). The protection conferred by breastfeeding persisted even when considering the role of several potential confounders. The researchers concluded that in this study, breastfeeding was associated with a decreased incidence of fever after immunisations.
Breastfeeding and protection against infection
A Greek study of 926 infants found that exclusive breastfeeding for six months contributed to protection against common infections during infancy and lessens the frequency and severity of infectious episodes.
Association between drugs used in labour and lower breastfeeding rates
It is often supposed that breastfeeding rates may be adversely affected by drugs taken in labour. This large retrospective study was carried out in Wales to investigate associations between drugs routinely administered in labour and breastfeeding outcomes at 48 hours, in healthy women and infants. At 48 hours, 43.3 per cent of women were not breastfeeding.
Statistical analysis confirmed previously reported associations of lower breastfeeding rates with epidural analgesia, intramuscular opioid analgesia and ergometrine. In addition it was found that oxytocin use, alone or in combination with ergometrine administered for prevention of postpartum haemorrhage (PPH), intravenous oxytocin and prostaglandins administered for induction of labour were all also associated with lower breastfeeding rates. The authors conclude that prospective studies on drugs used in labour are needed to investigate the potential associations between intrapartum medications and lower breastfeeding rates.
Does breastfeeding reduce the impact of maternal methadone use on the neonate? A cohort of 450 drug-dependent women who had been prescribed substitute methadone and who had given birth to singletons was monitored in one large maternity unit in the UK. One finding of the study was that when women breastfed their babies for more than 72 hours the baby was significantly less likely to need treatment for Neonatal Abstinence Syndrome (NAS) or baby withdrawals. The researchers suggest that this may be due to the combined effect of the benefits of breastmilk, the way breastfeeding soothes agitated babies and that small traces of the drugs taken by the mother may find their way into the breastmilk, thus lessening the baby’s withdrawal symptoms.
Based on their findings, researchers recommend that drug-misusing mothers should be encouraged to breastfeed their babies. A prolonged postnatal stay is recommended to help health-care professionals observe for signs of NAS, conduct social work assessment and arrange for parenting and community support for the mothers prior to discharge.
Dryden C, Young D Hepburn M et al (2009) Maternal methadone use in pregnancy: factors associated with the development of neonatal abstinence syndrome and implications for healthcare resources. BJOG; 116; 665-671
Exclusive breastfeeding and iron status
This study in India recruited 200 term babies, half of whom had anaemic mothers. The researchers found that iron parameters in babies of both groups were within normal limits at birth, 14 weeks and 6 months. The iron status of the babies had no relation to the breastmilk iron and lactoferrin concentration at any particular time. None of the babies studied who were exclusively breastfed until six months old developed iron deficiency anaemia or iron deficiency.
Breastfeeding and urinary tract infections
A prospective case-control study among 556 children aged 0-6 years in Sweden found that ongoing exclusive breastfeeding gave a significantly lower risk of urinary tract infection. A longer duration of breastfeeding gave a lower risk of infection after weaning, indicating a long-term mechanism. The protective role of breastfeeding was strongest directly after birth, then decreased until 7 months of age, after which age no effect was demonstrated.