My wife's early pregnancy symptom is to become quarrelsome, sometimes to the point of physical fight. Is there anything I can do to resolve this?

Answer:    
Since you know the reason for her behaviour, the issue should be easier to resolve. Pregnancy blues vary from one woman to another. Some are fortunate to have a stress-free pregnancy throughout the term, while some have it tough at the beginning. Others go through problems throughout the entire term of the pregnancy.

What a woman needs from her husband at this time is understanding and tolerance. A man should bear in mind that his wife is first and foremost fighting a battle within herself because she is not comfortable.
Naturally, her husband is the most likely person at the receiving end of her discomfort. Sometimes, it could also be a woman's way of getting at her husband as she feels he's responsible for her situation and sees no reason why she should bear the brunt of what they are both responsible for.
A man should understand that whatever reactions displayed by his wife in pregnancy are a function of the hormonal changes in her body system, he should therefore go the extra mile to give her love and attention knowing it is a tough period for her.