Complications of pregnancy

Question 1

What condition is defined as “persistent severe vomiting leading to weight loss and dehydration, as a condition occurring during pregnancy”?

Answer 1

Hyperemesis Gravidarum

Question 2

What cardiovascular changes occur during pregnancy?

Answer 2

⇧Ventricular wall muscle mass
⇧ Myocardial contractility
⇧ Stroke volume
⇧ Heart rate (minor – 10-20bpm)
⇧ Peripheral vasodilation
-25-30% drop in systemic vascular resistance
⇧ Cardiac output
-20% within first 8 weeks
-Maximum at 20-28 weeks (40%)
Reduced colloid oncotic pressure (10-15%)

Question 3

Is oedema a concern in pregnancy?

Answer 3

Most pregnant women will be oedemitous, due to a decrease in colloid osmotic pressure however it is only a concern when the swelling is rapid and around the face, neck or chest - this can be a sign of pre-eclampsia

Question 4

Why should you avoid positioning pregnant patients supline, how is this managed in resuscitation?

Answer 4

It can cause compression of the inferior vena cava:
-reduction in venous return to the heart
-stroke volume and cardiac output reduced (by up to 25%)
-reduction in uterine blood flow & placental perfusion

In resuscitation they will be led supline and left uterine displacement will be used

Question 5

What is Pregnancy Induced Hypertension (PIH) and what causes it?

Answer 5

Defined as a ersistently elevated BP >20 weeks gestation (>140/90)

No specific cause identified

Question 6

What are the dangers of Pregnancy Induced Hypertension (PIH)?

Answer 6

Blood vessel damage
Increased risk of cardiac failure and CVA

Question 7

How does pregnany affect the respiratory system?

Answer 7

⇧Oxygen demand
15% ⇧ in basal metabolic rate
20% ⇧ in oxygen consumption

Diaphragmatic elevation (uterus displaces it)
-Reduced functional residual capacity but no change in diaphragmatic excursion or vital capacity

SoB on exertion is normal for pregnant patients but acute, prolonged SoB or desaturation is abnormal

Question 8

What are the GI affects of pregnancy?

Answer 8

Most common is nausea and vomiting (morning sickness - 50-90% incidence)
-Hyperemesis Gravidarum

Decreased motility in the digestive tract

Question 9

What are the dangers of Hyperemesis Gravidarum?

Answer 9

Dehydration
Weight loss
Electrolyte imbalances
Compromises foetus nutrition

Question 10

What causes morning sickness?

Answer 10

It is thought to be a protective mechanism to protect the early foetus from anything harmful, it is associated with high levels of hCG (hCG rises rapidly at the beginning of pregnancy, falls in hCG levels are associated with a reduction in morning sickness)

Question 11

What are the causes and effects of reduced digestive tract motility in pregnant patients?

Answer 11

Caused by increased progesterone (smooth muscle relaxant)

Can cause:
-Slow emptying of stomach
-Reflux
-Bloating
-Haemorrhoids/fissures
-Constipation

Question 12

How does pregnancy affect blood volume?

Answer 12

There is an increased in blood volume
-Plasma up 50%

Usually no change in MCV (mean corpuscular volume) or MCHC (mean corpuscular haemoglobin concentration)

Question 13

What increases more during pregnancy RBCs or plasma? What effects does this have?

Answer 13

Plasma increases more
-Fall in Hb, RBCs and haematocrit causes relative anaemia and symptoms thereof

Question 14

How does pregnancy affect platelet count?

Answer 14

Pregnancy causes a progressive fall in platelet count

A significant drop - classed as thrombocytopenia - Can indicate preeclampsia, HELLP, or ITP (idiopathic thrombocytic purpura)

Question 15

What is HELLP syndrome?

Answer 15

HELLP (Haemolysis, Elevated Liver enzymes and Low Platelets) syndrome is a life-threatening pregnancy complication usually considered to be a variant of preeclampsia.

Question 16

How does pregnancy affect demand for iron, folate and vitamin B12?

Answer 16

2-3x increase in demand for iron
-Haemoglobin synthesis
-Foetal development

10-20 x increase in demand for folate
-DNA, RNA, metabolises amino acids

2 x increase in demand for vitamin B12

Question 17

What causes pregnant women to be in a constant hypercoaguable state?

Answer 17

Increased clotting factors VIII, X and XI
50% increase in fibrinogen
Decrease in fibrinolytic activity
Decreased endogenous anticoagulants

Question 18

For how long are pregnant patient at an increased risk of clotting and venous thrombosis?

Answer 18

From first trimester until 12 weeks post-partum

Question 19

What is pre-eclampsia?

Answer 19

Persistent hypertension associated with high protein urine levels in pregnant or recently pregnant women, a precursor to eclampsia

Question 20

What is eclampsia?

Answer 20

A condition in which one or more convulsions occur in a pregnant woman suffering from high blood pressure, often followed by coma and posing a threat to the health of mother and baby.

Question 21

When can pre-eclampsia affect women?

Answer 21

From 20 weeks gestation up to 6 weeks after delivery

Question 22

Are the symptoms of pre-eclampsia severe or mild?

Answer 22

It can range from asymptomatic to mild to severe or life threatening symptoms

Question 23

What is the significance of high proteinuria in pre-eclamptic patients?

Answer 23

It is a sign of kidney damage, and can damage other organs

Question 24

What are the risk factors for pre-eclampsia?

Answer 24

First pregnancy
Multiple gestations (twins etc.)
Age > 35
Existing hypertension
Diabetes
Obesity
Family history

Question 25

What is the pathophysiology of pre-eclampsia?

Answer 25

The exact cause in unknown.

It is linked with placental abnormalities, specifically in the utero-placental arteries which should expand during pregnancy.

In pre-eclampsia these arteries become fibrous and cannot expand enough causing a poorly perfused placenta which leads to intrauterine growth restriction and possibly placental abruption or foetal death.

The fibrous arteries release inflammatory proteins which enter the mothers circulation and cause endothelial damage causing vasocontriction and salt retention in the kidneys.

There can also be areas of isolated vasospasm which can cause oliguria if present in the kidneys, visual disturbances in the eyes, or liver injury and swelling contributing to right upper quadrant pain and HELLP syndrome.

Endothelial damage also causes the blood vessels to become more permeable, this combined with the lower colloid osmotic pressure in the blood caused by proteinuria leads to excessive water loss into the tissues. This results in generalised, pulmonary and possibly cerebral oedema.

Question 26

Which blood pressure values define pre-eclampsia and severe pre-eclampsia?

Answer 26

Pre-eclampsia: BP>140/90
Severe pre-eclampsia: BP>160/110

Question 27

What can hypertension in severe pre-eclampsia lead to?

Answer 27

Haemorrhagic stroke
Placental abruption

Question 28

What is the pathophysiology of HELLP syndrome?

Answer 28

Endothelial cell injury leads to thrombi formation in the blood using lots of platelets, circulating RBCs can collide with these thrombi causing haemolysis and low platelets.

Hepatic vasoconstriction/vaso-spasm causes elevated liver enzymes

Question 29

What percentage of patients with severe pre-eclampsia/eclampsia will develop HELLP syndrome?

Answer 29

10-20%

Question 30

What are the symptoms of pre-eclampsia?

Answer 30

BP > 140/90
Upper right quadrant pain
Headache
Nausea and vomiting
Oedema in face, neck or chest
Pulmonary oedema
Visual changes
Nose bleeds

Question 31

How does DIC occur in pregnancy?

Answer 31

Pre-eclampsia and placental abruption can cause increased clotting. This leads to excessive consumption of clotting factors and subsequent haemorrhage/DIC.