02/04 Pre-eclampsia for Midwifery Students

Introduction to Pre-eclampsia

• Speaker Introduction: Lou McKenna, an educator and midwife at Auckland City Hospital.

• Course Context: MD 7038, Science of Recovery.

• Topic Overview: Focus on pre-eclampsia with the aim to cover important aspects.

Learning Objectives

• Understanding pathophysiology of early and late onset pre-eclampsia.

• Discussion of hypertensive disorders of pregnancy:

  • Definitions and risk factors.

  • Investigations and results.

• Preventative measures: prophylactic aspirin and calcium.

Pre-eclampsia Overview

• Defined as a condition characterized by hypertension and signs of damage to another organ system, most often the liver and kidneys, during pregnancy.

• Insufficient remodeling of spiral arteries leading to oxidative stress and systemic inflammation.

Pathophysiology of Pre-eclampsia

• Types of Pre-eclampsia:

  • Early Onset: Occurs before 32 weeks.

  • Late Onset: Occurs after 32 weeks.

• Early onset is often associated with fetal growth restriction.

Physiological Changes in Pregnancy

• The body undergoes significant changes:

  • Vascular: Decreased systemic vascular resistance; increased blood flow to tissues.

  • Cardiac: Increased heart rate and left ventricular remodeling.

  • Metabolic: Increased cholesterol and triglycerides to support placental function.

  • Immune response: Enhanced inflammatory response to support the fetus.

Spiral Artery Remodeling

• Function: Essential for ensuring adequate blood flow to the placenta and fetal development.

• Remodelling includes:

  • Dilation of arteries due to trophoblastic invasion allowing for low-resistance, high-flow environment.

• Poor remodeling leads to:

  • Restricted blood flow (malperfusion) and placental stress, contributing to pre-eclampsia development.

Risk Factors for Hypertensive Disorders

• Congenital Risk Factors: History of hypertension, kidney disease, diabetes, older maternal age.

• Lifestyle Factors: Obesity, lack of physical activity, poor diet.

• Pregnancy Factors: Multiple pregnancies, previous history of pre-eclampsia.

Clinical Presentation of Pre-eclampsia

• Symptoms include hypertension and the presence of protein in urine.

• Common signs to monitor:

  • Swelling (edema), headaches, visual disturbances, upper abdominal pain.

  • Important to differentiate normal pregnancy changes from pathological ones.

Importance of Monitoring

• Frequent monitoring of blood pressure and other markers is critical in identifying and managing pre-eclampsia early on.

• Timely interventions can prevent severe complications.

Research and Future Directions

• Current research focuses on better understanding the underlying mechanisms of pre-eclampsia and improving diagnostic tools.

• Ongoing discussions on the implications of late-onset pre-eclampsia.

Wrap-up before Break

• Emphasized the complexity of pre-eclampsia and the importance of understanding the physiological changes during pregnancy to effectively manage the condition.

• Session to resume after a scheduled break to further discuss research and implications for midwifery practice.

• Insufficient trophoblastic invasion of the spiral arteries is a crucial factor in the development of pre-eclampsia.

• Understanding pre-eclampsia involves recognizing its multi-system effects, including the physiological vascular changes that occur during pregnancy.

• There are increased demands on the ventricular system due to changes in maternal physiology.

• Gestational hyperlipidaemia and gestational insulin resistance are significant physiological adaptations during pregnancy that can impact pre-eclampsia.

• During pregnancy, an inflammatory and immune response occurs that plays a role in placental formation and blood supply.

• Remodeling of the spiral arteries is essential for healthy placentation and involves the trophoblastic invasion which creates a low-resistance, high-flow environment.

• The placenta performs functions analogous to the lungs and gastrointestinal system, supporting both maternal and fetal needs.

• Pre-eclampsia is characterized by hypertension and the presence of protein in urine, often stemming from disturbed placentation.

• Early-onset pre-eclampsia is associated with factors such as disturbed placentation and interrupted spiral artery remodeling leading to placental oxidative stress.

• The role of Thromboxane A2 and Placental Growth Factor (PIGF) are important in understanding the changes occurring in the placenta during pre-eclampsia.

• Endothelial damage is a common consequence of pre-eclampsia, leading to increased vessel permeability and contributing to the symptoms observed.

• Differences between early-onset and late-onset pre-eclampsia are crucial, with late-onset pre-eclampsia potentially linked to several theories regarding maternal systemic inflammatory responses.