By Anna Griffin | Edited by Frances Conti Ramsden
Why clear communication around low-dose aspirin matters for preventing preeclampsia and supporting safer pregnancies.
Picture this. A pregnant woman attends her first antenatal appointment. She's told she's at increased risk of complications and handed a prescription for low-dose aspirin - with little explanation of why, what to expect, or how long to take it.
Her nausea worsens in the weeks that follow. It must be the tablets. She stops.
At 32 weeks, she's admitted with pre-eclampsia. Blood pressure sky-high. Emergency delivery. Her baby in the NICU. The birth she had planned - and those first days she'd imagined - gone in a matter of hours.
Severe early-onset pre-eclampsia is uncommon. The failures that leave women unprotected against it are not.
Pre-eclampsia is preventable — and we are failing to prevent it
Pre-eclampsia affects 5–8% of pregnancies in the US and rates are rising, driven by increasing rates of obesity, older maternal age, and chronic hypertension (Ayyash et al., JAMA, 2024). It remains one of the leading causes of maternal and infant mortality and morbidity worldwide. Once it develops, the only treatment is delivery. There is no cure and only one well-evidenced prevention: low-dose aspirin, ideally started by 16 weeks of pregnancy.
Prevention of pre-eclampsia through low-dose aspirin is one of the most robustly evidenced treatments in obstetrics. The ASPRE trial demonstrated a 62% reduction in preterm pre-eclampsia with low-dose aspirin (Rolnik et al., 2017). Guidelines from ACOG, USPSTF, and NICE are unambiguous in their recommendations for aspirin in women at increased risk of pre-eclampsia.
And yet: large proportions of eligible women are not taking it.
The gap is two-layered — and both layers are systemic
Aspirin non-adherence is too often framed as a patient problem. The evidence tells a different story. This is a system failing women at two distinct levels.
Layer one: the prescription gap. Non-adherence often begins before the first tablet is dispensed, because it was never prescribed. Real-world data consistently shows that significant proportions of high-risk women leave their booking appointment without a prescription (Ayyash et al., 2023). Risk factors include not only the obvious - gestational diabetes, chronic hypertension, prior pre-eclampsia - but combinations of subtler factors: first pregnancy, obesity, older maternal age, multi-fetal gestation. Social determinants of health matter too: low socioeconomic status and Black maternal ethnicity are now recognised as moderate risk factors, reflecting the systemic inequities embedded in healthcare access and delivery.
In addition, due to lack of knowledge, Pharmacists are often reluctant to dispense aspirin over the counter to pregnant women, creating a second barrier for those with limited insurance or disrupted access to care.
Layer two: the adherence cliff. Even when aspirin is prescribed, adherence falls - and the consequences are dramatic. Analysis shows that aspirin's effectiveness in preventing pre-eclampsia drops from 76% to 41% when adherence falls below 90% (Atkins et al., BJOG, 2025). That is not a marginal difference. That is the difference between a drug that works most of the time to less than half.
Why does adherence collapse? The reasons are interconnected and deeply human. Women often are not told clearly why aspirin matters, how long to take it, or what to do when nausea makes it difficult. Pregnancy symptoms are misattributed to the medication. Women may stop in the second trimester, believing the risk has passed - when guidance recommends continuing until at least 36 weeks. Taking a daily tablet with no perceivable effect, against a complication that hasn't happened yet, requires a level of trust in the system that the system hasn't earned.
These are failures of system design and communication.
The cost of inaction
This is a clinical crisis - and a financial one.
Pre-eclampsia pregnancies cost an average of $41,790 in combined maternal and infant medical costs, compared to $13,187 for uncomplicated pregnancies (Hao et al., 2019). Much of that burden falls on infant care: NICU admission, preterm birth complications, extended stays. Across the US population, pre-eclampsia accounts for an estimated $2.18 billion in incremental healthcare costs in the first 12 months post-delivery alone (Stevens et al., AJOG, 2017). Hypertensive disorders of pregnancy represent the single largest contributor to maternal morbidity costs - $7.5 billion of $18.7 billion total (O'Neil et al., PLOS, 2022).
And the burden extends across a lifetime. Women with a history of pre-eclampsia carry a 2–4-fold increased risk of hypertension, stroke, heart disease, and diabetes in the decades that follow (Palmiero et al., JCM, 2025).
A month's supply of low-dose aspirin costs less than $10. Preventing a single case of severe pre-eclampsia avoids tens of thousands of dollars in downstream cost - not counting ICU admissions, litigation, or the long-term cardiovascular sequelae described above.
The asymmetry is stark.
What closing the gap actually requires
Closing the aspirin gap requires the same systematic thinking we apply to every other evidence-based intervention in obstetric care. That means:
- Standardised risk assessment at booking, with aspirin prescribing embedded into the workflow rather than dependent on individual clinician recall
- Brief, structured counselling that explains the rationale, addresses tolerability, and sets expectations for duration — delivered consistently, not incidentally
- Equitable access, including clear guidance for pharmacists and reduced barriers for women without insurance or reliable healthcare access
- Continuity of reinforcement across the care pathway — not a single conversation at 12 weeks and silence thereafter
The women most likely to benefit from aspirin — those from lower socioeconomic backgrounds, those with pre-existing conditions, those in underserved rural communities — are also those least likely to receive it and most likely to struggle with access and adherence.
Where digital health fits
The clinical touchpoints needed to close this gap are time-constrained. Midwives describe insufficient time and resources for complex medication counselling (Vinogradov et al., Midwifery, 2023). Physicians are often not involved until complications arise. The system has real capacity constraints - and those constraints disproportionately affect the most vulnerable patients.
Digital health is not a substitute for that system. But it can extend its reach in ways that matter: personalised risk communication, medication reminders calibrated to the individual, accessible and evidence-based information to counteract the misinformation that fills the vacuum when clinical counselling falls short.
At Megi Health, this is precisely what we're building. Our AI-driven platform uses clinically validated guidance and longitudinal patient data to stratify pre-eclampsia risk and provide pregnant women with personalised, accessible support - putting evidence-based care into the hands of women who need it, between the appointments where that information should be - but often isn't - delivered.
Initiatives like the March of Dimes' Low Dose, Big Benefits campaign (2024) are also working to normalise conversations about aspirin and increase awareness among both patients and providers. These efforts matter. But awareness without infrastructure only closes part of the gap.
The tools exist. The evidence is unambiguous. The cost of inaction - human and financial - is well-documented.
We need to treat aspirin prophylaxis as a system responsibility.
References
ACOG/SMFM Practice Advisory (2021). Low-Dose Aspirin Use for the Prevention of Preeclampsia.
Al-Jawahiri. (2025). Misinformation and women's health: Rebuilding trust in evidence-based care. IJGO. DOI: 10.1002/ijgo.70753
Atkins et al. (2025). Optimising Aspirin Use for Pre-Eclampsia Prevention: The Critical Role of Dose, Timing and Adherence. BJOG. DOI: 10.1111/1471-0528.18095
Ayyash et al. (2024). Trends in Preeclampsia Risk Factors in the US From 2010 to 2021. JAMA. DOI: 10.1001/jama.2024.8931
Ayyash et al. (2023). Provider adherence to aspirin prophylaxis prescription guidelines for preeclampsia. Pregnancy Hypertens. DOI: 10.1016/j.preghy.2023.09.002
Bonten TN et al. (2014). Effect of aspirin intake at bedtime versus on awakening on circadian rhythm of platelet reactivity. Thromb Haemost. DOI: 10.1160/TH14-05-0453
Hao et al. (2019). Maternal and Infant Health Care Costs Related to Preeclampsia. Obstetrics & Gynecology.
March of Dimes (2024). Low Dose, Big Benefits™
Mogos et al. (2025). Trends and Disparities in the Utilization of Low-Dose Aspirin for Pregnancies with Moderate or High-Risk of Preeclampsia. JWH. DOI: 10.1177/15409996251405065
O'Neil et al. (2022). Societal cost of nine selected maternal morbidities in the United States. PLOS. DOI: 10.1371/journal.pone.0275656
Palmiero et al. (2025). Long-Term Cardiovascular Risk and Maternal History of Pre-Eclampsia. JCM. DOI: 10.3390/jcm14093121
Roberge et al. (2017). The role of aspirin dose on the prevention of preeclampsia and fetal growth restriction. AJOG. DOI: 10.1016/j.ajog.2016.09.076
Rolnik et al. (2017). Aspirin versus Placebo in Pregnancies at High Risk for Preterm Preeclampsia. NEJM. 377:613–622.
Stevens et al. (2017). Short-Term Costs of Preeclampsia to the United States Healthcare System. AJOG.
Vinogradov et al. (2023). Let's talk aspirin: A survey of barriers and facilitators faced by midwives when engaging in conversations about aspirin with women at risk of pre-eclampsia. Midwifery. DOI: 10.1016/j.midw.2023.103860
Vinogradov et al. (2024). Barriers and facilitators of adherence to low-dose aspirin during pregnancy. PLOS. DOI: 10.1371/journal.pone.0302720