This tiredness ranges from very little to as if you are living with a female bear in deep hibernation. A smart husband who plans ahead can also take advantage of this by planing the pregnancy so his wife is in the first trimester during the championships of his favorite sport. Another thing you can expect to some degree is morning sickness. The name is kind of general and with good reason. This sickness can be anything from a little upset tummy to full blown, hold nothing back, tossing of one's cookies.
Most women fall somewhere in between.
The sickness can also appear at any time or throughout the day. So remember if you see your wife heading towards the bathroom don't stop her to ask her what's for breakfast. Also, many women have to go to the bathroom more often during this trimester. This is another one of those perfectly normal but totally baffling chemical reactions. Once again, if you see your wife rushing quickly towards the bathroom make sure you stay clear.