Some people have a preference for babies born under a certain sign; the rat and dragon are extremely popular because the former is the first animal of the zodiac cycle and the latter is considered the most powerful and auspicious of all the creatures. Three years ago, there was a misinformed rush to have golden pig babies; it was actually the Year of the Fire (rather than metal) Pig, but a journalist had not done his homework properly and many people took him at his word.
The Year of the Tiger is not considered to be a popular one as it is believed by some people that children born under this sign will be aggressive and bad tempered. That is an irrational fear because deciding whether a child will bring fortune or adversity to its parents is properly done by referring to the time, day and month of birth, not just the year.
Babies are not like fashion trends; they aren't hot or not depending on the season. Experienced astrologers can analyse astrology charts to identify the years when a woman's chances of falling pregnant will be highest - and that may well not be in a Year of the Rat or Dragon. By waiting for a preferred animal year, a woman may reduce her chance of falling pregnant at all. Babies should be valued and appreciated as blessings, regardless of which Chinese zodiac sign they belong to.