Medical Conditions – Cardiac Disease, Thrombophilias, Rhesus Immunisation

and Paula Briggs2

(1)
Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia
(2)
Sexual and Reproductive Health, Southport and Ormskirk Hospital, Southport, UK
 

Cardiac Disease

Definition

This includes congenital cardiac abnormalities, rheumatic valvular heart disease, ischaemic heart disease, cardiomyopathy and pulmonary hypertension.

Incidence

Congenital heart disease in pregnancy affects less than 1 % of women.
Pregnancy increases the risk of myocardial infarction (MI) three to four fold. The risk of MI in women over 40 years of age is 30 times that of younger women.
The risk of death from ischemic heart disease in pregnancy in the UK is 1 in 130,000.

Aetilogy and Pathogenesis

The normal physiological changes of pregnancy result in additional demands on the heart. These include an increase in blood volume (plasma volume increasing more than red cell mass), peripheral vasodilatation and an increase in cardiac output (up to 40–50 % by 20–28 weeks). These demands increase even further during labour and immediately following delivery.
Patients with pre-existing risk factors include those with hypertension, pre-eclampsia, diabetes, smoking, obesity and hyperlipidaemia.

Clinical Assessment

History

  • Chest pain in pregnancy needs to be investigated (consider aortic dissection if severe)
  • Shortness of breath (especially postural), should raise suspicion regarding cardiomyopathy

Examination

  • Regular assessment of pulse rate and rhythm and blood pressure
  • Cardiac auscultation to detect murmurs suggestive of valvular heart disease

Investigations

  • ECG
  • Chest X ray
  • Echocardiogram
  • CT scan of chest (to exclude aortic dissection)
  • Oxygen saturation in women who are cyanosed

Treatment

Medical

  • Joint responsibility (cardiologists and obstetricians)
  • Mode and timing of delivery should be planned at the 32–34 week visit

Surgical

  • Minor – Minimise cardiovascular stress by eliminating pushing during the second stage with elective assisted vaginal delivery
  • Major – Caesarian Section is usually only required for obstetric indications

Complications

Cardiac failure, death

Prognosis

One in thirteen women who have a MI in pregnancy will die

Rhesus Disease

Definition

Rhesus immunisation of a woman who is Rhesus negative in response to blood from a Rhesus positive foetus entering her circulation.
There are also many other antigens on the surface of red blood cells, not as well known as Rhesus, such as Kell, MNS, and Kidd which may also cause iso-immunisation, but Rhesus is the most common and therefore the most relevant clinically.

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Sep 23, 2016 | Posted by in OBSTETRICS | Comments Off on Medical Conditions – Cardiac Disease, Thrombophilias, Rhesus Immunisation

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