Human fertility

  • Men and women have hormonal cycles which determine both when a woman can achieve pregnancy and when a man is most virile. The female cycle is approximately twenty-eight days long, but can deviate greatly from this "norm".
  • The male cycle is also variable. Men can ejaculate and produce sperm at any time of the month, but their sperm quality dips occasionally.
  • Furthermore, age also plays an equally significant role for both men and women.