Safe period is calculated by
The safe period is calculated by the length of menstrual cycle The shoest cycle minus 18 days gives the first day of feile period and longest cycle minus 10 days gives the last day of the feile period The couple should abstain from coitus during feile period Reference : Park&;s textbook of preventive and social medicine, 23rd edition, Page no: 507
Length of menstrual cycle
Duration Date of ovulation
Length of ovulation
Length of luteal phase
Demography and family planning