The Conception Chart is the chart for the time that the baby was conceived about 9 months before birth. E. H. Bailey published his classic book “The Prenatal Epoch” in 1916, which describes that the Ascendant at the time of birth and Moon at the time of conception are related to each other. The formula is fairly complex and the relationship depends on the relationship of the Moon to to the Asc at birth and the gender of the baby is determined by which of 28 sections of the zodiac the Moon is in at conception. Several dates are produced and the date on which the gender is correct and the Moon-Asc relationship is close is the conception date.