Estimate of births averted in the Profamilia program

Kelly's parity approach is used to estimate the number of live births averted at 6, 12 and 18 months after acceptance by 3,518 acceptors at nine Profamilia clinics in 1969. The calculated rates per thousand acceptors at 6, 12, and 18 months, respectively, are 137, 267, and 363. In order to obtain a general idea of the number of abortions averted by contraceptive use through the Profamilia program, Kelly's formula is also used, with modifications, to estimate the number of fetal losses (stillbirths and spontaneous and induced abortions) averted by the sample of users. It is estimated that 86 fetal losses per thousand acceptors are averted at 18 months postacceptance.