Related Experiment Video
Updated: Jun 28, 2026
Disruption of the Mouse Blood-Brain Barrier by Small Extracellular Vesicles from Hypoxic Human Placentas
Published on: January 26, 2024
Changes in microparticle numbers and cellular origin during pregnancy and preeclampsia
Christine A R Lok1, Joris A M Van Der Post, Ian L Sargent
1Department of Obstetrics and Gynaecology, Academic Medical Center, Amsterdam, The Netherlands. c.a.lok@amc.uva.nl
Background:
Microparticles (MP) are pro-coagulant vesicles derived from various cells. Evidence is accumulating that MP are of pathophysiological relevance in autoimmune, cardiovascular, and thromboembolic diseases and inflammatory disorders. Therefore, their role in the development of preeclampsia was investigated and MP from preeclamptic patients influenced endothelial-dependent vasodilatation. Knowledge about changes in circulating MP numbers during pregnancy and preeclampsia is lacking. We determined this longitudinally and investigated whether these numbers related to the severity of preeclampsia.
Methods:
Samples were obtained from pregnant women and preeclamptic patients during pregnancy and postpartum. MP were isolated and studied by flow cytometry.
Results:
During pregnancy, MP were decreased at 12 weeks gestation and then returned to postpartum values. In patients with preeclampsia, MP numbers were reduced at 28 and 36 weeks (both p = 0.04). Monocyte-derived MP were elevated in preeclampsia at 28 (p = 0.007), 32 (p = 0.02), and 36 weeks (p = 0.01), as were erythrocyte-derived MP at 28 weeks (p = 0.04). Placenta-derived MP increased in pregnancy and preeclampsia. During pregnancy, a correlation was present between placenta-derived MP and systolic blood pressure (r = 0.33, p = 0.015). No other correlations were found.
Conclusions:
During pregnancy, numbers of MP initially decrease and subsequently normalize. Placenta-derived MP increase, possibly because of placental growth. In preeclampsia, reduced numbers of PMP are due to decreased platelet counts. Increased numbers of monocyte-derived MP reflect monocyte activation, which may be an expression of the systemic inflammation in preeclampsia. Lack of correlation between numbers of MP and severity of preeclampsia suggests that MP numbers alone do not explain the reported vascular effects of MP.
Insights
Microparticle numbers initially decrease during pregnancy then normalize. In preeclampsia, monocyte-derived microparticles increase, suggesting systemic inflammation, but numbers don't correlate with disease severity.
Area of Science:
- Obstetrics and Gynecology
- Hematology
- Immunology
Background:
- Microparticles (MPs) are vesicles involved in various diseases.
- Their role in preeclampsia and changes during pregnancy are not well understood.
- Previous studies suggest MPs influence endothelial function.
Purpose of the Study:
- To determine longitudinal changes in circulating microparticle numbers during pregnancy and preeclampsia.
- To investigate the relationship between microparticle numbers and preeclampsia severity.
Main Methods:
- Longitudinal collection of blood samples from pregnant women and preeclamptic patients.
- Isolation and quantification of microparticles using flow cytometry.
Main Results:
- Microparticle numbers decreased at 12 weeks gestation, returning to postpartum levels.
- Preeclamptic patients showed reduced overall microparticle counts at 28 and 36 weeks.
- Elevated monocyte-derived and erythrocyte-derived microparticles were observed in preeclampsia.
- Placenta-derived microparticles increased during pregnancy and preeclampsia, correlating with systolic blood pressure.
Conclusions:
- Microparticle levels fluctuate during normal pregnancy.
- Increased monocyte-derived microparticles in preeclampsia may indicate systemic inflammation.
- Reduced overall microparticles in preeclampsia are linked to lower platelet counts.
- Microparticle numbers alone do not fully explain preeclampsia's vascular effects.
