Pregnant women in Australia are confronting a medication system in which the ability to control severe morning sickness may depend as much on household income as on medical need, according to a new population-based study led by researchers at the University of Technology Sydney. The analysis suggests that Australia’s Pharmaceutical Benefits Scheme (PBS), the national program that subsidises prescription medicines, is not adequately aligned with the therapeutic needs of pregnant patients. As a result, clinicians are frequently prescribing medicines outside standard PBS arrangements, creating an uneven system in which patients with greater financial resources can access a broader range of treatments.
Nausea and vomiting in pregnancy (NVP) affects as many as 80 percent of pregnant women. Although often referred to as morning sickness, symptoms can occur throughout the day and range from mild nausea to persistent vomiting, dehydration, weight loss and, in its most severe form, hyperemesis gravidarum. Despite its prevalence, only an estimated 10 to 20 percent of women experiencing NVP use conventional anti-nausea medications. Researchers say this low treatment rate may reflect concerns about medicine safety during pregnancy, limited access to subsidised therapies and the tendency of some patients and clinicians to tolerate significant symptoms rather than navigate a restrictive pharmaceutical system.
The study, published in Acta Obstetricia et Gynecologica Scandinavica, examined PBS dispensing records associated with almost 300,000 pregnancies over a five-year period. The researchers compared medication use and public expenditure across regions with different socioeconomic profiles. Their aim was not simply to measure how much the government spent, but to determine whether the design of the subsidy system influenced which antiemetic medicines women could obtain. The results indicate that the PBS does provide important financial protection, but that its narrow range of pregnancy-relevant options may also produce unequal patterns of access.
One of the clearest findings involved ondansetron, a medicine widely used to control nausea and vomiting. Although ondansetron does not have a specific pregnancy indication or dedicated PBS listing for NVP, it accounted for 54 percent of total PBS expenditure on anti-nausea medicines dispensed during pregnancy. Its use increased more rapidly in lower-income areas, suggesting that doctors may have been relying on subsidised pathways to make the medicine affordable for patients who could not pay the full cost themselves. In Australia, prescribing a drug “off-label” means using it for a condition, patient group or stage of life not explicitly covered by its formal regulatory approval. Off-label prescribing is legal and common in medicine, particularly in pregnancy, but it can involve limited evidence, additional clinical responsibility and inconsistent access.
The researchers describe this pattern as a kind of “Robin Hood” effect. Clinicians appear to be using available system mechanisms to help financially vulnerable patients obtain medicines they believe are clinically necessary. Such prescribing may also reduce pressure on hospitals if effective treatment prevents dehydration, malnutrition or complications that would otherwise require emergency care or inpatient management. However, the workaround is not an equitable substitute for a clearly regulated and properly subsidised treatment framework. It can depend on individual prescribers’ knowledge, willingness to prescribe outside usual restrictions and ability to navigate administrative rules.
The roots of this cautious regulatory environment extend back decades. The thalidomide tragedy, in which a medication prescribed to pregnant women caused severe birth defects, transformed drug regulation and permanently influenced how medicines are evaluated for use during pregnancy. Because pregnant people are often excluded from clinical trials, evidence about the safety and effectiveness of many medicines can remain incomplete. Regulators and pharmaceutical companies may also be reluctant to invest in pregnancy-specific studies, particularly when the potential legal and ethical risks are high. The result is a paradox: pregnancy is a period when medication decisions are especially important, yet high-quality evidence can be more limited than it is for other patient populations.
The study’s findings suggest that this evidence gap is reinforced by the structure of the PBS. Women on lower incomes may be restricted largely to older medicines that are subsidised, even when clinicians consider newer or repurposed treatments more appropriate for a particular patient. Women with greater financial capacity, by contrast, may be able to purchase non-PBS medicines privately, allowing them to access a wider selection of guideline-recommended therapies. In practice, two patients with similar symptoms may therefore receive different treatment options because of their ability to pay rather than differences in disease severity.
The researchers argue that this disparity represents both a public health and policy problem. When clinicians prescribe outside formal PBS restrictions to ensure that vulnerable patients receive treatment, the system may be spending public money in ways that are less transparent and less strategically planned. At the same time, women who cannot afford private prescriptions may experience prolonged vomiting, missed work, reduced nutrition and avoidable hospital visits. Associate Professor Luke Grzeskowiak of Flinders University said that the current arrangement allows disadvantaged women to rely on a narrow set of subsidised medicines while wealthier patients can self-fund the full range of options.
The authors are calling for Australia’s medication funding structures to be updated, particularly as maternal health has been identified as a national priority. They recommend expanding the range of medicines evaluated and subsidised for pregnancy-related conditions, including both newer drugs and existing medicines that could be repurposed on the basis of emerging evidence. Dr Hannah Jackson, the study’s lead author and a recent PhD graduate from UTS, said reform could create a more dynamic, evidence-based system that responds to the real treatment needs of pregnant women. Without change, the researchers warn, Australia may continue to see socioeconomic inequality, widespread off-label prescribing and potentially inefficient public spending built into the management of one of pregnancy’s most common medical problems.
Subject of Research: People
Article Title: Pharmaceutical policy and off-label prescribing in pregnancy: A population-based historical cohort study analyzing inequality in access to antiemetics within Australia’s Pharmaceutical Benefits Scheme
News Publication Date: 11 June 2026
Web References: https://doi.org/10.1111/aogs.70283
References: Acta Obstetricia et Gynecologica Scandinavica, DOI: 10.1111/aogs.70283
Keywords: pregnancy, morning sickness, nausea and vomiting in pregnancy, antiemetics, ondansetron, Pharmaceutical Benefits Scheme, PBS, off-label prescribing, maternal health, health inequality, Australia, pharmaceutical policy
