Can You Get Preeclampsia With No Risk Factors?

Yes, you can get preeclampsia with no traditional risk factors, including in a first pregnancy. A low-risk classification describes your screening profile. It does not describe your actual risk. A clean risk-factor screen lowers the odds, but it doesn't rule preeclampsia out. Ask your care team about blood pressure checks, whatever your risk-factor status.

Yes. Here's Why Your Screen Doesn't Tell the Full Story

Yes, preeclampsia can occur in women with no traditional risk factors, including in first pregnancies.

That assumption had a reasonable basis. In one large American cohort study, preeclampsia was diagnosed in 23.5% of women classified as high-risk versus 3.0% of women classified as low-risk under the U.S. Preventive Services Task Force (USPSTF) criteria (Miracle of Life cohort study). That gap is real: recognized risk factors do meaningfully increase incidence. A clean screen felt like a safety signal because, statistically, it was one.

But 3.0% is not zero. The SCOPE study, a multicenter study of over 5,600 healthy first-time (nulliparous) pregnant women, starts from the observation that more than half of all preeclampsia cases occur in healthy first-time pregnant women, who by definition carry none of the parity-based risk history that screening relies on (Kenny et al., Hypertension, 2014). This point is specific to first pregnancies: it describes nulliparous women, not pregnancy in general. Even when researchers in that same cohort combined risk factors with biomarker testing to try to predict who would develop preeclampsia, the resulting model showed only modest discrimination (a validation AUC of 0.68, on a scale where 1.0 is perfect discrimination and 0.5 is no better than chance). That helps explain why screening based on known factors alone is structurally incomplete. A low-risk classification describes your screening profile. It does not describe your actual risk.

What that raises is a harder question. If the risk-factor list doesn't fully predict who develops preeclampsia, what was it built to do in the first place? That's a tool-design question, and the answer changes what a clean screen actually tells you.

Risk-Factor Screening Was Built to Target Treatment, Not to Clear You

The tool that assessed your preeclampsia risk was not built to clear you.

Risk-factor classification systems like USPSTF's exist primarily to decide who should receive aspirin prophylaxis, a preventive treatment typically started in early pregnancy, not to certify who is safe. (The USPSTF recommendation is also supported by the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine — see References.) The tool produces a candidacy decision for a preventive intervention with a gestational deadline. It was not designed to certify that anyone not flagged is safe.

This isn't a design flaw. It's the expected performance of a tool operating exactly within its intended scope. A screen built to identify prophylaxis candidates will do that correctly; it was never built to provide a safety clearance for the women it doesn't flag.

Being not-flagged did not mean not-at-risk. For women never identified for heightened attention, the practical cost is concrete: cases still occur in this population, in women who may not be monitoring at all.

What This Means for Monitoring

The gap established above has a direct implication: a clean risk-factor screen means fewer known flags, not confirmed safety.

Standard prenatal guidance recommends regular blood pressure checks, urine tests for protein, and attention to warning symptoms as preventive measures for preeclampsia. Early, consistent prenatal care is essential for monitoring and managing potential risk, and neither recommendation is limited to women who were flagged.

Some signs mean call your care team the same day, no matter the number, and no matter what your risk-factor screen said:

• A reading at or above 160/110
• A headache that won't go away
• Vision changes: blurry vision, spots, or flashing lights
• Pain in your upper belly, under your ribs
• Sudden swelling in your face or hands
• Sudden nausea or trouble breathing

Home blood pressure monitoring is not a replacement for clinical care. It's adjunctive to it. Whatever readings you gather are most useful when interpreted alongside your provider, not in isolation.

The practical step is a conversation, not a number. At your next appointment, ask your OB or midwife about blood pressure monitoring regardless of your risk-factor status, and ask whether your visit schedule should include urine protein screening even though your initial screen was clear. Write down whatever thresholds they give you. Those thresholds belong to your clinical picture; they are not something this article can supply.

Bottom line: a "low-risk" screen means the standard checklist didn't flag you. It doesn't mean preeclampsia can't happen to you. Monitor regardless of your risk-factor status, and know the warning signs above.

Frequently Asked Questions

Can you get preeclampsia if you have no risk factors?

Yes. The researchers behind the SCOPE study of more than 5,600 healthy first-time pregnant women note that more than half of all preeclampsia cases occur in healthy first-time pregnant women (Kenny et al., Hypertension, 2014). A clean risk-factor screen lowers the odds, but it doesn't rule preeclampsia out.

Why does risk-factor screening miss so many preeclampsia cases?

Standard risk-factor tools like USPSTF's were built mainly to decide who should get preventive aspirin, not to certify that everyone else is safe. Even when researchers combined risk factors with biomarker testing, the model showed only modest discrimination (a validation AUC of 0.68) — which is why a "low-risk" classification describes your screening profile, not your actual risk.

Should I still monitor my blood pressure at home if I was told I'm low-risk?

Yes. Standard prenatal guidance recommends regular blood pressure checks and attention to warning symptoms regardless of risk-factor status. Contact your care team the same day for a reading at or above 160/110, or for symptoms like a persistent headache, vision changes, upper-belly pain, sudden swelling, or sudden nausea or trouble breathing.

For a deeper look at why the screening gap creates a monitoring blind spot for low-risk pregnancies, see our related piece, "You Have No Risk Factors. That's Not the Same as No Risk." (/learning-hub/monitor-if-healthy-pregnancy).

References

1. Kenny LC, Black MA, Poston L, Taylor R, Myers JE, Baker PN, McCowan LM, Simpson NA, Dekker GA, Roberts CT, Rodems K, Noland B, Raymundo M, Walker JJ, North RA. Early Pregnancy Prediction of Preeclampsia in Nulliparous Women, Combining Clinical Risk and Biomarkers: The Screening for Pregnancy Endpoints (SCOPE) International Cohort Study. Hypertension. 2014;64(3):644-652. https://pubmed.ncbi.nlm.nih.gov/25122928/
2. Cohort Study Evaluating U.S. Preventive Services Task Force (USPSTF) Preeclampsia Risk Assessment and Aspirin Prophylaxis Recommendations (the "Miracle of Life" study). 2025. https://pubmed.ncbi.nlm.nih.gov/40674048/
3. American College of Obstetricians and Gynecologists (ACOG). Low-Dose Aspirin Use During Pregnancy. ACOG Committee Opinion No. 743. July 2018. https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2018/07/low-dose-aspirin-use-during-pregnancy
4. ACOG, Society for Maternal-Fetal Medicine (SMFM). Low-Dose Aspirin Use for the Prevention of Preeclampsia and Related Morbidity and Mortality. Practice Advisory. December 2021. https://www.acog.org/clinical/clinical-guidance/practice-advisory/articles/2021/12/low-dose-aspirin-use-for-the-prevention-of-preeclampsia-and-related-morbidity-and-mortality