An index of reproductive efficiency (RE) is proposed as a social indicator that will meet the need to consider various forms of pregnancy wastage, to compare their relative costs, and to guide reproductive health policy accordingly. This article discusses conceptual and measurement aspects of RE. Conversion of wanted to unwanted pregnancies and the reverse, interpretation of abortion in relation to other pregnancy outcomes, defining the end point for the reproductive process and criteria for the events to be included as significant outcomes are conceptual issues. Measurement problems include: whether aggregation is justified, prospective and retrospective tracking of outcomes, record limitations, duplication of adversities in a single pregnancy, and selection of optimal rates for comparison. A measurement of RE for the entire United States based on the National Natality Survey of 1964–1966 is presented, showing 74.5 percent of pregnancies resulting in healthy liveborn infants. For those years, data on abortions could not be included. Within the group of reported pregnancy losses, the importance of congenital abnormalities and low-birth-weight babies is enhanced by application of economic weights based on associated medical care costs. Changing opportunities for birth timing, prenatal and infant care, and control of family size are social means of reducing adverse outcomes associated with teenage pregnancy and high-parity births, often found together with poverty. Successive increments in RE may be progressively more expensive to achieve, and cost effectiveness comparisons will be necessary.
Effects on Synchronization and Reproductive Efficiency of Delaying the Removal of the Intravaginal Progesterone Device by 24 h in the 5d Co-synch Protocol in Heifers
