Speaker's Highlight

• Don Sin University of British Columbia, St. Paul Hospital (Canada)
  Kenneth R. Chapman Toronto General Hospital Research Institute (Canada)
• Parameswaran Nair McMaster University (Canada)
  Carolyn Calfee UCSF (U.S.A.)
• Gregory P. Downey University of Colorado School of Medicine (U.S.A.)
  David A. Schwartz University of Colorado School of Medicine (U.S.A.)
• Neil Schluger Tuberculosis Control Branch, California Department of Public Health (U.S.A.)
  Nick Kim Critical Care & Sleep Medicine, University of California San Diego (U.S.A.)
• Nicola Hananiah Baylor College of Medicine (U.S.A.)
  Jae-Joon Yim Seoul National University College of Medicine (Republic of Korea)
• Koichiro Asano Tokai University School of Medicine (Japan)
  Diahn-Warng Perng Taipei Veterans General Hospital (Taiwan)
• Konstantinos Kostikas University of Ioannina (Greece)
  Karin Klooster University Medical Center Groningen (Kingdom of the Netherlands)

• The safety of biologic therapies in asthma during pregnancy

  Pregnancy can change asthma control through hormonal shifts, altered airway physiology, increased symptom awareness and changes in medication routine. An uncontrolled attack can lead to hypoxaemia, emergency treatment and preterm birth, so maintaining stable lung function is the immediate maternal and foetal priority.

  Biologic therapies for severe asthma include monoclonal antibodies such as omalizumab, mepolizumab, benralizumab and dupilumab. Their pregnancy safety is supported by reassuring observational data and registries, although a low detected risk is not the same as proven absence of risk. Treatment decisions therefore depend on the medicine, gestational timing, asthma severity and available safety evidence.

  Australian clinicians must balance this evidence with access through the Pharmaceutical Benefits Scheme, product information approved by the Therapeutic Goods Administration and coordination between respiratory, obstetric and primary care teams. The key clinical question is usually whether continued biologic treatment offers greater protection than withdrawal, rather than whether pregnancy automatically requires a change.

  Therapy	Principal target	Pregnancy evidence summary	Clinical consideration
  Omalizumab	IgE	The longest pregnancy safety record, with reassuring registry and observational findings	Specialist-led dosing and injection observation remain important
  Mepolizumab	IL-5	Growing registry data show no clear increase in adverse pregnancy outcomes	Review disease control and injection timing with the respiratory team
  Benralizumab	IL-5 receptor	Encouraging registry findings, although fewer pregnancies have been exposed	Individual uncertainty should be discussed rather than assumed away
  Dupilumab	IL-4 and IL-13 pathways	Pregnancy data from asthma and other indications are reassuring	Coordinate with obstetric care and review adverse effects

  Why asthma control drives the safety calculation

  Severe asthma itself is associated with pre-eclampsia, gestational hypertension, preterm birth and low birth weight. Some of these outcomes may reflect the underlying inflammatory disease, its treatment or both, which makes it difficult to isolate the effect of any single medicine. Preventing exacerbations remains a central part of pregnancy care.

  Stopping an effective biologic can produce a rapid loss of control in severe eosinophilic or allergic asthma. Reduced inhaled corticosteroid exposure and increased rescue medication use may follow, while a major exacerbation can require hospital treatment and systemic corticosteroids. Established treatment should therefore be reassessed carefully, not discontinued automatically.

  Reading the pregnancy evidence

  Biologics differ from small-molecule medicines in how they reach the foetus. Transfer of IgG-class antibodies through the placenta usually becomes more efficient during the second half of pregnancy, with timing and extent varying between agents. First-trimester exposure is generally lower, but this pharmacokinetic pattern cannot substitute for clinical outcome data.

  The strongest evidence comes from pregnancy registries, cohort studies and manufacturer pharmacovigilance systems. Across these sources, available biologic therapies have not demonstrated a consistent increase in congenital malformations, miscarriage, preterm delivery or foetal death. Severe asthma outcomes generally remain stable when effective treatment is continued, although the evidence for each medicine is uneven.

  These findings carry important limitations. Registries may miss pregnancies or outcomes, and women with severe asthma differ from those with mild disease. Manufacturer-sponsored monitoring can introduce reporting bias, while uncommon outcomes remain difficult to assess in relatively small datasets. The evidence is therefore reassuring, most strongly for omalizumab and increasingly supportive for the newer agents, but it does not justify complacency or unsupervised continuation.

  Choosing and continuing a biologic

  For a patient already stable on a biologic, continuation is often the most defensible approach when the medicine has a substantial pregnancy record and there is no unacceptable adverse effect. Any decision to stop should involve the respiratory specialist and consider the likely consequence of recurrent exacerbations, including possible hospital admission.

  Starting a biologic during pregnancy requires a different risk–benefit discussion. The same disease severity that would justify treatment outside pregnancy still applies, but clinicians should consider the agent’s available data, gestation, comorbidities and the extent to which another therapy can maintain control. A pregnancy is not a reason to initiate treatment that was otherwise clinically unnecessary, yet it is also not a reason to leave severe asthma inadequately treated.

  Medication exposure alone generally does not justify routine invasive foetal testing. Standard obstetric assessment, medication-specific review and attention to maternal asthma control remain the priorities. Where the available product information or emerging safety signal raises a specific concern, the respiratory and obstetric teams can agree on additional monitoring.

  Australian prescribing and connected care

  Australia’s Therapeutic Goods Administration assesses medicines for quality, safety and efficacy under the Therapeutic Goods Act 1985. Clinicians should confirm that a product is included in the Australian Register of Therapeutic Goods and review its current product information and, when available, Australian Public Assessment Reports. Pregnancy wording and warnings may differ between products within the same biologic class.

  The Pharmaceutical Benefits Scheme subsidises selected asthma biologics for eligible patients, often after specialist assessment and with specific severity or biomarker criteria. Scripts may be supplied through public hospital services or private prescribing, and some medicines support pharmacy-led home administration after training. Co-payment, cold-chain requirements and injection access should therefore be considered alongside medical safety. Regional patients, including residents of remote First Nations communities, may also need transport, culturally safe support and Medicare-funded telehealth to maintain treatment continuity.

  Australia’s mixed public and private health system can separate respiratory follow-up from maternity care, even when both services operate in the same city. A shared plan should identify the responsible clinician, update the medication list and include a written asthma action plan in line with National Asthma Council Australia guidance. Warm-season grass and mould spores in Melbourne, Sydney and Brisbane can coincide with viral infections and place extra pressure on control, making trigger review and rapid access to rescue medication particularly relevant. For delegates attending APSR 2022, the congress’s official registration guidance provides participation information separately from these individual clinical arrangements.

  A pregnancy-ready asthma plan

  A pregnancy-ready plan records current asthma control, inhaler technique, trigger management, biologic dosing and the person responsible for treatment during an exacerbation. It should be visible to the treating team and updated as gestation advances, especially if nausea, vomiting, reflux or altered routines affect adherence or administration.

  Delivery plans also need a clear response to worsening symptoms during labour or a postoperative admission. Rescue medication, escalation thresholds and access to urgent obstetric and respiratory care should be agreed in advance. For a patient requiring a biologic, the obstetric clinician should understand its indication, schedule and available pregnancy safety information.

  The concrete next step is a respiratory medicine review before the next biologic dose or refill, with the gestational age, current medication list and asthma action plan brought to that appointment and the continuation or change decision documented.

  Richard Russell Nuffield Department of Clinical Medicine, University of Oxford (United Kingdom)
• Mona Bafadhel King’s College London (United Kingdom)
  David Jackson Guy’s and St Thomas’ Hospital, King’s College London (United Kingdom)
• James Chalmers University of Dundee (United Kingdom)
  David Price University of Aberdeen (United Kingdom)