<P> Men also experience a decline in fertility as they age though in a very gradual and later process in contrast to women's fertility as men's biological clock declines simply by each age (loses 1 percent every age) in comparison to women's biological clock where it begins drop sharply and rapidly after 38 years of age; for example, the average time to pregnancy if a man is under 25 is just over 4.5 months but nearly two years if a man is over 40 (if the woman is under 25). The risk of genetic defects is greatly increased due to the paternal age effect . Children with fathers aged 40 or older are more than five times as likely to have an autism spectrum disorder than children fathered by men aged under 30 . Researchers estimate that compared to a male fathering a child in his early 20s, there is double the chance of the child getting schizophrenia when the father is age 40, and triple the risk of schizophrenia when the father is age 50 (though, for most people this means the risk goes from approximately 1 in 121 when a man is 29, to 1 in 47 when a man is age 50 to 54). Men's fertility declines throughout the lifespan, with the volume and fecundity of a man's semen quality and sperm motility (the ability of sperm to move towards an egg) decrease continually between the ages of 20 and 80 . The incidence of dwarfism and miscarriage also increases as men age </P> <P> In the United States, between 1997 and 1999, 539 births were reported among mothers over age 50 (four per 100,000 births), with 194 being over 55 . </P> <P> The oldest mother to date to conceive, was 71 years, and the youngest mother, 5 years old . According to statistics from the Human Fertilisation and Embryology Authority, in the UK more than 20 babies are born to women over age 50 per year through in - vitro fertilization with the use of donor oocytes (eggs). </P> <P> Maria del Carmen Bousada de Lara is the oldest verified mother; she was aged 67 years 3 days when she gave birth to twins; she was 130 days older than Adriana Iliescu, who gave birth in 2005 to a baby girl . In both cases the children were conceived through IVF with donor eggs . The oldest verified mother to conceive naturally (listed currently as of 26 January 2017 in the Guinness Records) is Dawn Brooke (UK); she conceived a son at the age of 59 years in 1997 . </P>

Who is the oldest person to have a baby naturally