Preeclampsia is a major complication of pregnancy, characterized by hypertension and organ damage. Although it has been known for centuries, its causes remain partly mysterious. A recent study published in the American Journal of Obstetrics and Gynecology takes stock of current knowledge regarding the etiology of this syndrome.
Researchers highlight how preeclampsia has no single cause, but is the result of multiple factors that converge, activating a “common pathway” characterized by:
- Dysfunction of blood vessel endothelial cells
- Intravascular inflammation
- Stress of the placental syncytiotrophoblast
The main causes identified include:
- Utero-placental ischemia: reduced blood flow to the placenta appears to be a key factor, especially in early-onset preeclampsia
- Maternal infections: both oral (periodontitis) and systemic (e.g., COVID-19) infections have been associated with an increased risk
- Gut dysbiosis: alterations in maternal gut microbiota could predispose to the syndrome
- Gestational diabetes and obesity: significantly increase risk, probably through inflammatory mechanisms
- Sleep disorders: sleep apnea and snoring are risk factors
- Molar pregnancy: overgrowth of placental tissue may cause preeclampsia
- Fetal diseases: some diseases of the fetus can induce the syndrome in the mother
- Autoimmune mechanisms: particularly antibodies against angiotensin II receptors
- Placental aging: early senescence of the placenta may be involved
- Maternal-fetal immunological incompatibility: inadequate immune tolerance toward the fetus may lead to preeclampsia
The study highlights how these factors often overlap and interact with each other. In addition, early-onset preeclampsia (before 34 weeks) appears to have somewhat different mechanisms than late-onset preeclampsia.
Better understanding the causes of this syndrome is critical to improving prevention and treatment. Future research should clarify the relative weight of the various factors and how they combine in determining the onset of preeclampsia in individual patients.
In conclusion, this work reminds us of the complexity of preeclampsia and the need for a multifactorial approach to fully understand its etiology and develop effective treatment strategies.
Read the full paper in American Journal of Obstetrics and Gynecology
