Miscarriage

Definition

When a mother loses a baby naturally. It occurs before the 20th week of pregnancy, and is the most common complication of early pregnancy. When a mother experiences 3 or more, it is referred to as recurrent miscarriage.

Epidemiology

It is difficult to assess accurately, but around 15% of known pregnancies end in miscarriage. This doesn't include those that end before the women realises she is pregnant.

Pathophysiology

The exactly physiology of miscarriage is poorly understood, and varies due to various causes. Basically, the main cause is either a problem with the foetus, which presents at a point, say 4 weeks in, and the pregnancy terminates; or a problem with the mother, such as structural or hormonal abnormalities.

Trophoblastic disease molar

Risk Factors

• Age - older women are more likely to miscarry - if you're under 35 its around 7.5%, if you're over 40 its nearly 25%.
• Polycystic Ovary Syndrome - Miscarriage rates in women with PCOS are around 50%, compared to the normal 15%.
• Multiple pregnancy
• Poorly controlled diabetes - but not that which is well controlled
• Fever over 37.7...^oC
• Smoking - 30-50% increased risk
• Previous history of miscarriage

On the plus side, previous contraceptive pill use results in a slight reduction in the risk of miscarriage

Clinical Features

Often asymptomatic but vaginal bleeding, lower abdominal pain plus absence of symptoms of pregnancy are suggestive of miscarriage. When it is asymptomatic, it's found by USS.

Investigations

• Clotting - Abnormal maternal clotting is a big cause of miscarriage.
• Chromosomal - If mum or dad has X/Y translocation, only 50% of foetus' will be viable.
• Uterine abnormality - Fairly rare, but, treatable surgically.
• Endocrine - Looking for PCOS & Thyroid.