<prompt> Contraceptive efficacy is measured byPearl Index and Life table analysisPearl Index onlyLife table analysis and Couple protection ratePearl Index and Couple protection rate  <response>: Contraceptive Efficacy: Is assessed by measuring the number of unplanned pregnancies that occur during a specified period of exposure and use of a contraceptive method. Two methods used are:Pearl IndexLife table analysisLife Table Analysis LTA as measure of contraceptive efficacy: LTA calculates a failure rate per month of use Better measure than PI 