Inside . . . Fertility in Both Males and Females Decline with
Age David Dunson, PhD, a bio-statistician from the National
Institute of Environmental Health Sciences (NIEHS) has recently
developed a mathematical model to determine the probability of
pregnancy on given days of a woman's menstrual cycle. His
statistical model takes into consideration a number of variables
that affect day specific fecundability, including frequency of
intercourse, accuracy of biomarkers of fertility and age.
Dunson, Professor Bernardo Columbo from the Department of
Statistical Science at the University of Padua, Italy and Donna
Baird (a colleague from NIEHS) utilized Dunson's statistical
model to estimate the effects of male and female age on natural
fertility and the length of the fertile window.1 They determined
probabilities of pregnancy associated with intercourse on
specific days relative to ovulation and compared them across the
following age groups; 19-26, 27-29; 30-34 and 35-39 years. Data
for the analysis was obtained fr