Standard Days Method or SDM

Standard Days Method or SDM

Women track their fertile periods (usually days 8 to 19 of each 26 to 32 day cycle) using cycle beads or other aids

How it works: 
Prevents pregnancy by avoiding unprotected vaginal sex during most fertile days.
Effectiveness to prevent pregnancy: 
95% with consistent and correct use. 88% with common use (Arevalo et al 2002)
Comments: 
Can be used to identify fertile days by both women who want to become pregnant and women who want to avoid pregnancy. Correct, consistent use requires partner cooperation.