Asthma Management Handbook

Infant feeding and asthma prevention


Recommend breastfeeding where possible for its health benefits, but do not advise prolonged exclusive breastfeeding (as recommended in the past for allergy prevention). Instead, recommend the introduction of a variety of solid foods at around 6 months (but not before 4 months), while continuing to breastfeed.

Note: Prolonged exclusive breastfeeding does not prevent asthma in children. Delayed introduction of commonly allergenic foods increases the risk of developing food allergy.

How this recommendation was developed

Adapted from existing guidance

Based on reliable clinical practice guideline(s) or position statement(s):

  • ASCIA 20161

Last reviewed version 2.0


For infants at high risk of asthma (e.g. family history of asthma and allergies), do not recommend the use of hydrolysed formula or soy formula in preference to breast milk, or in preference to standard formula where breastfeeding is not possible.

Note: Hydrolysed formula and soy formula are not effective in asthma prevention.

How this recommendation was developed

Evidence-based recommendation

Based on literature search and formulated by multidisciplinary working group

Key evidence considered:

  • Boyle et al. 20162

Last reviewed version 2.0

Do not recommend dietary restrictions for breastfeeding women to prevent asthma in their children.

How this recommendation was developed

Adapted from existing guidance

Based on reliable clinical practice guideline(s) or position statement(s):

  • ASCIA 20161

Last reviewed version 2.0

Do not routinely recommend dietary supplements (e.g. prebiotics/probiotics, vitamins, fish oil) as an asthma-prevention strategy for breastfeeding women or for infants.

How this recommendation was developed

Adapted from existing guidance

Based on reliable clinical practice guideline(s) or position statement(s):

  • ASCIA 20161

Last reviewed version 2.0

More information

Safety of asthma medicines while breastfeeding

Australian product information identifies some medicines that are known to pass into breast milk (e.g. adrenaline, aminophylline, prednisolone, sodium cromoglycate, terbutaline).3

The concentration of active ingredient in breast milk is likely to be low for several common asthma medicines (e.g. beclomethasone dipropionate, budesonide, fluticasone propionate, combination fluticasone propionate/salmeterol, nedocromil, ipratropium bromide).3

For some asthma medicines (e.g. formoterol, omalizumab, montelukast), or test substances (e.g. mannitol, used in bronchial provocation [challenge] testing), it is not known whether or not the active ingredient is excreted into breast milk, so caution is recommended.3

Australian product information identifies only a small number of asthma medicines that are not recommended for breastfeeding women (e.g. adrenaline, aminophylline, hydrocortisone for injection, prednisolone), and recommends that caution is needed when others (e.g. omalizumab, montelukast) are given to breastfeeding women.3

Information about the safety of medicines during lactation (included in product information for each medicine) emphasises the need to balance the potential benefits of asthma treatment with the possible risks to the infant.3

Note: Product information provided by pharmaceutical manufacturers and registered with the Therapeutic Goods Administration is written and approved when the medicine is first marketed, but is not routinely updated as new evidence becomes available. When product information includes a caution or contraindication for breastfeeding, health professionals should check current evidence before advising the woman about her choices, so that mothers do not stop breastfeeding unnecessarily, based on incomplete information.

Up to date information is available from the following sources:

  • The Drugs and Lactation Database (LactMed), compiled by the US National Library of Medicine, provides comprehensive current information on the safety of medicines during breastfeeding
  • The National Prescribing Service (NPS) Medicines Line provides information for the public about medicines and safety: 1300 MEDICINE (1300 633 424)
  • Telephone information services about the safety of medicines while breastfeeding are also available for health professionals and breastfeeding women in some areas of Australia.

Table. Local pregnancy and breastfeeding safety information services Opens in a new window Please view and print this figure separately:

Systemic corticosteroids and breast milk

Peak plasma level of systemic corticosteroid occurs at approximately 2 hours post dose, so peak milk level will also occur around this time. Therefore, the infant’s exposure to corticosteroids in breast milk can be further reduced by breastfeeding the infant just before each daily dose and avoiding feeding again until at least 4 hours after the dose.4, 5

If high-dose corticosteroids need to be used for longer than 10 days, the infant should be monitored for growth and development.45

The US National Library of Medicine’s Drugs and Lactation Database (LactMed) states that: limited information indicates that maternal doses of prednisolone up to 50 mg produce low levels in milk and would not be expected to cause any adverse effects in breastfed infants. With high maternal doses, avoiding breastfeeding for 4 hours after a dose should markedly decrease the dose received by the infant. However, this [manoeuvre] is probably not necessary in most cases.

Prenatal and childhood exposure to tobacco smoke

Tobacco smoking by pregnant women damages children’s respiratory health. It also increases the risk of stillbirth, spontaneous abortion, reduced foetal growth, preterm birth, low birth weight, placental abruption, sudden infant death, cleft palate, cleft lip and childhood cancers.6

Risk of developing asthma

Prenatal exposure to tobacco smoke and exposure during infancy increase the risk of wheezing during early childhood.7

Effects on children's asthma

Evidence from an Australian cohort study suggests that children with asthma whose mothers smoked during pregnancy benefit less from treatment with inhaled corticosteroids, and show less improvement in airway hyperresponsiveness over time, than those with asthma but no intrauterine exposure to smoke.8

Breastfeeding and allergy prevention

Earlier evidence suggested that the risk of asthma might be reduced by prolonged exclusive breastfeeding. The reduction in risk was thought to be greatest in children at high risk of asthma, but small in other children.9 This evidence was mainly from studies of poor methodological quality.10

However, recent studies did not confirm that prolonged exclusive breastfeeding protected against development of asthma,11 allergic rhinitis,11 or other allergic disease such as atopic dermatitis (eczema).12 

Limited evidence from observational or poor quality studies suggests that breastfeeding while solid foods are introduced may help reduce the infant's risk of developing allergies.1 The Australasian Society of Clinical Immunology and Allergy (ASCIA) current guidelines for Infant feeding and allergy prevention recommend breastfeeding for at least 6 months for its range of benefits, with complementary foods introduced at around 6 months (but not before 4 months) while continuing to breastfeed.1

Exclusion of allergenic foods from the maternal diet has not been shown to prevent allergies.1 ASCIA recommends against maternal dietary restrictions while breastfeeding.1

ASCIA’s guidelines for Infant feeding and allergy prevention and Guide to introducing solid foods contain practical advice for mothers13 For updates on ASCIA advice, refer to the ASCIA website (

Last reviewed version 2.0



  1. Australasian Society of Clinical Immunology and Allergy (ASCIA). Infant feeding and allergy prevention. ASCIA, Sydney, 2016. Available from:
  2. Boyle, R. J., Ierodiakonou, D., Khan, T., et al. Hydrolysed formula and risk of allergic or autoimmune disease: systematic review and meta-analysis. BMJ. 2016; 352: i974. Available from:
  3. Therapeutic Goods Administration, TGA eBusiness Services. Information about prescription medicines in Australia, Australian Government Department of Health 2013. Available from:
  4. Briggs G, Freeman R, Yaffe S. Drugs in Pregnancy and Lactation – A Reference Guide to Fetal and Neonatal Risk. Lippincott, Williams & Wilkins, Philadelphia, 2008.
  5. Hale T. Medications and Mothers’ Milk: Manual of Lactational Pharmacology. 14th edn. Hale Publishing, Amarillo, 2010.
  6. Zwar N, Richmond R, Borland R, et al. Supporting smoking cessation: a guide for health professionals. Updated 2012. The Royal Australian College of General Practitioners (RACGP), Melbourne, 2011. Available from:
  7. Burke H, Leonardi-Bee J, Hashim A, et al. Prenatal and passive smoke exposure and incidence of asthma and wheeze: systematic review and meta-analysis. Pediatrics. 2012; 129: 735-744. Available from:
  8. Cohen RT, Raby BA, Van Steen K, et al. In utero smoke exposure and impaired response to inhaled corticosteroids in children with asthma. J Allergy Clin Immunol. 2010; 126: 491-7. Available from:
  9. Prescott SL, Tang ML. The Australasian Society of Clinical Immunology and Allergy position statement: summary of allergy prevention in children. Med J Aust. 2005; 182: 464-467. Available from:
  10. Lodge, C. J., Tan, D. J., Lau, M. X., et al. Breastfeeding and asthma and allergies: a systematic review and meta-analysis. Acta Paediatr. 2015; 104: 38-53. Available from:
  11. Kramer MS, Matush L, Vanilovich I, et al. Effect of prolonged and exclusive breast feeding on risk of allergy and asthma: cluster randomised trial. BMJ. 2007; 335: 815. Available from:
  12. Flohr C, Nagel G, Weinmayr G, et al. Lack of evidence for a protective effect of prolonged breastfeeding on childhood eczema: lessons from the International Study of Asthma and Allergies in Childhood (ISAAC) Phase Two. Br J Dermatol. 2011; 165: 1280-1289. Available from:
  13. Castro-Rodriguez, J. A., Forno, E., Rodriguez-Martinez, C. E., Celedon, J. C.. Risk and protective factors for childhood asthma: what is the evidence?. J Allergy Clin Immunol Pract. 2016; 4: 1111-1122. Available from: