Abstract:

Conception, term pregnancy and birth of a live-born infant can occur under minimal nutrition in younger women although extreme under nutrition or over-exertion limits fertility. Alternatively, excessive nutrition and obesity is associated with polycystic ovarian syndrome, an increasing cause of infertility in developed nations. Undernourished babies are at risk of very low birth weight, disability and/or infant mortality and very low birth weight is associated with early onset of chronic disease and shortened lifespan. Protein may be the most critical peri-conception nutrient but many minerals and vitamins are critical for optimal development. Reproduction in primates demonstrates that increasing birth weight is associated with decreasing lifetime fertility of a species. In humans increased birth weight is also associated with decreased male fertility in all countries where suitable data is available. Since increased median birth weight is associated with increased longevity, balancing loss of male fertility may be a desirable outcome of natural selection. Ageing in females is associated with loss of fertility and increased risk of unfavourable outcomes. Since ageing is associated with changes in fatty acid metabolism, it is proposed that suitable supplementation of fatty acids and mitochondrial enzymes might improve outcome in healthy women aged 38 and older.