There are significantly more newborn boys than girls, but men die at a younger age than women. In France, for example, there are 107 boys born for every 100 girls.The thing is, we can't know the probability of the second child being a boy or a girl from that alone. Just because we have assessed that there are two options doesn't mean that they are equally likely. Simply due to population trends, it is slightly more likely that the other child is a girl. Not much though, something like 52% preference.
U.N. estimates vary between 101-100 and 103-100 of men outnumbering women in the world.