Rett syndrome affects one in every 12,500 female live births by age 12 years.

The theoretical odds on male versus female births are 50-50.

Biology dictates that for every hundred female births there should be about 105 or 106 male births.

Every three years, on average, the female births a single young, after a seven-month gestation.

The incidence of Turner syndrome in live female births is believed to be around 1 in 2000.

The authors did the research because it had been noted that male births increased in relation to female births after a war.

Triple X results during division of a parent's reproductive cells and occurs about once in every 1,000 female births.

This is a chromosomal condition that is found in approximately 1 of every 2,500 live female births.

Few female births and even then we cannot probe their Other Memories.

The typical ratio of male to female births is about 105 males for every 100 females.