MCQ Paper 2, answer 28

28. Pregnancy and Clotting.

a.	clotting factors increase and fibrinolysis decreases	True
b.	platelet counts rise by 30%	False
c.	the risk of thromboembolism is increased in older mothers	True
d.	the risk of thromboembolism is particularly associated with LSCS	True
e.	the risk of thromboembolism decreases if lupus anticoagulant is present	False
f.	warfarin is not teratogenic	False
g.	sub-cutaneous heparin is associated with loss of bone mass	True
h.	pulmonary embolism ranks second to hypertensive disease in causes of maternal mortality	False
i.	disseminated intravascular coagulation is associated with placenta previa	False
j.	disseminated intravascular coagulation is associated with severe pre-eclampsia	True
k.	disseminated intravascular coagulation is associated with retained products of conception	True

Numerous clotting factors increase in pregnancy, particularly II, VII, VIII and X.

Fibrinolysis declines.

These phenomena, in combination with venous stasis, lead to a marked tendency to clotting, which increases more than five fold in pregnancy.

Bed rest, so beloved of Obstetricians in days of yore, greatly increases the risk.

Simple hospitalisation has its risks too, particularly increased consumption of cigarettes.

Platelets do not rise.

Indeed there may be a physiological fall, due to increased turnover.

You would think that lupus anticoagulant would reduce the risk of clotting, but the converse is true.

Warfarin (see MCQ9, question 32) should be avoided in the first trimester, as it is teratogenic.

It causes fetal abnormalities, varying from facial malformations, e.g. saddle nose and frontal bossing to mental retardation and eye damage.

In later pregnancy it may cause microhaemorrhages in the baby's brain, producing mental retardation and even microcephaly.

It should also be avoided at the time of delivery when it crosses the placenta and anticoagulates the baby.

You do not want the baby to be anticoagulated when it is undergoing the stresses of delivery as there is an increased risk of intracranial bleeding.

Heparin is dealt with in MCQ8, question 31.

It is a large molecule and does not cross the placenta.

It is associated with loss of bone and thrombocytopenia, which leads, perversely, to a thrombotic tendency.

Thromobembolism is the leading “direct” cause of maternal death.

Suicide was the commonest cause of maternal death in the 97-99 and 2000-02 Reports.

But cardiac disease topped the list in 2003-05.

Cardiac disease is one of the “indirect” causes of maternal mortality.

"Direct" and "indirect" are terms you need to know.

“Direct” means directly due to pregnancy: e.g. eclampsia or bleeding from placenta previa.

"Indirect" means something not caused by pregnancy, though perhaps worsened by being pregnant: e.g. cardiac disease or cancer.

You’ll have this repeated ad nauseam through the MCQs to make sure you know it!

Disseminated intra-vascular coagulation is associated with placental abruption, but not placenta previa.

In the former, there is much damage to placenta and myometrium with release of thromboplastins, in which these tissues are rich.

Thrombophilia is dealt with in MCQ9. question 33.

HELLP syndrome is dealt with in MCQ6, question 20.

Pregnancy induced hypertension in MCQ4, question 16.