What Causes Preeclampsia and Can It Be Prevented?
At a Glance
Preeclampsia is caused by abnormal placental development and narrow blood vessels early in pregnancy, not by your diet or lifestyle choices. While unavoidable for some, high-risk patients can often lower their chances of developing preeclampsia by taking daily low-dose aspirin.
In this answer
3 sections
No, you did not cause your preeclampsia. It is incredibly common for patients to feel intense guilt or worry that they did something wrong, but preeclampsia is not caused by eating the wrong foods, exercising too much, working too hard, or normal daily stress [1][2]. The root cause of this condition begins deep within the body very early in pregnancy and is entirely out of your control.
The Root Cause: Placental Development
Preeclampsia fundamentally begins with how the placenta attaches and forms inside the uterus during the first trimester [3][4]. To supply enough blood to a growing baby, tiny blood vessels in the uterus—called spiral arteries—must expand and become much wider [3]. In pregnancies that develop preeclampsia, this widening process does not happen correctly, leaving the blood vessels too narrow [3][4][5].
Because these spiral arteries remain narrow, the placenta does not receive adequate blood flow [4][6]. In response to this stress, the placenta releases specific proteins into the mother’s bloodstream [7][8]. These proteins cause widespread inflammation and irritate the lining of the mother’s blood vessels, a condition known as endothelial dysfunction [4][6]. This widespread blood vessel reaction is what causes the classic symptoms of preeclampsia, such as high blood pressure and stress on organs like the kidneys [4][7].
Unavoidable Risk Factors
The failure of the spiral arteries to widen is influenced by complex, unavoidable biological processes. Research shows this is driven by:
- Genetics: Specific genetic markers make some individuals more susceptible [9][10].
- Immune system reactions: The mother’s immune system may not fully recognize or tolerate the new placental cells, leading to an abnormal interaction during early development [11][12].
- Medical history: Pre-existing conditions like lupus, chronic hypertension, diabetes, or carrying multiples (twins, triplets) naturally increase the baseline risk [13][14].
None of these factors are related to a lack of willpower, poor lifestyle choices, or something you “should have done differently.”
Medical Prevention Strategies
Because preeclampsia starts at the cellular level during early placental implantation, it cannot be prevented with diet changes, bed rest, or sheer effort once it has begun.
However, for individuals identified as having a higher baseline risk before or during early pregnancy, there are proven medical strategies to lower the chances of preeclampsia developing in the first place:
- Low-Dose Aspirin: Medical guidelines strongly recommend daily low-dose aspirin for high-risk patients [15][16]. When started early in pregnancy (ideally before 16 weeks), low-dose aspirin actually helps improve the way the placenta forms and significantly reduces the risk of the condition developing early [17][18][19].
- Calcium Supplements: For pregnant individuals who do not get enough calcium in their normal diet, taking a daily calcium supplement has been shown to offer additional protective benefits [20][21].
(Always speak with your doctor or midwife before starting any new medications or supplements during pregnancy.)
Once you are diagnosed with preeclampsia, the focus shifts from prevention to careful management. This typically means frequent blood pressure monitoring, regular blood and urine tests for you, and extra ultrasounds (such as growth scans and fetal heart rate monitoring) to ensure your baby is growing safely until delivery.
Common questions in this guide
Did I do something to cause my preeclampsia?
Can preeclampsia be prevented?
How does the placenta cause preeclampsia?
What are the main risk factors for developing preeclampsia?
Questions to Ask Your Doctor
Curated prompts to bring to your next appointment.
- 1.Based on my medical history, am I a candidate for low-dose aspirin in my next pregnancy, and when exactly should I start taking it?
- 2.Are there any specific blood tests or ultrasound measurements we will use to monitor how the placenta is functioning right now?
- 3.What is my target blood pressure, and at what specific reading should I call you or go to the hospital?
- 4.How often will we monitor my baby's growth and wellbeing going forward?
Questions For You
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References
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This page provides educational information about the biological causes of preeclampsia. Always consult your obstetrician or midwife for medical advice and before starting any new medications or supplements during pregnancy.
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