Sex differences in human physiology
Female fertility declines after age 30 and ends with the menopause. Female physical experiences vary depending on external forces such as diet, marriage patterns, culture, and other aspects. In Western nations menstruation begins to affect females at 13 and menopause starts around 51. In non-industrialized countries, on the other hand, most females begin menstruation at a later age. More lactation in the lifetime of non-western females inhibits ovulation and extends the number of fertile years. Pregnancy in the 40s or later has been correlated with increased risk of Down syndrome in the children. Males are capable of fathering children into old age. Paternal age effects in the children include multiple sclerosis, autism, breast cancer and schizophrenia, as well as reduced intelligence. Adriana Iliescu was reported as the world's oldest woman to give birth, at age 66. Her record stood until Maria del Carmen Bousada de Lara gave birth to twin sons at Sant Pau Hospital in Barcelona, Spain on December 29, 2006, at the age of 67. In both cases IVF was used. The oldest known father was former Australian miner Les Colley, who fathered a child at age 93.
Amenorrhea
The social effects of amenorrhoea on a person vary significantly. Amenorrhoea is often associated with anorexia nervosa and other eating disorders, which have their own effects. If secondary amenorrhoea is triggered early in life, for example through excessive exercise or weight loss, menarche may not return later in life. A woman in this situation may be unable to become pregnant, even with the help of drugs. Long-term amenorrhoea leads to an estrogen deficiency which can bring about menopause at an early age. The hormone estrogen plays a significant role in regulating calcium loss after ages 25–30. When her ovaries no longer produce estrogen because of amenorrhoea, a woman is more likely to suffer rapid calcium loss, which in turn can lead to osteoporosis. Increased testosterone levels cause by amenorrhoea may lead to body hair growth and decreased breast size. Increased levels of androgens, especially testosterone, can also lead to ovarian cysts. Some research among amenorrhoeic runners indicates that the loss of menses may be accompanied by a loss of self-esteem.