ABSTRACT
No regular statistical data have been taken in the USSR on the interval between births. Retrospective surveys are the only source of information on birth timing. Tabulations of a 1985 survey, which polled 5 percent of the USSR population, provide a detailed picture of the situation in the late 1970s and early 1980s. This was not the first study of the timing of births using retrospective surveys. Such indicators were obtained for the first time on the basis of a 1960 survey (Sifman, 1974).
