One of the major points of Omran’s theory is that infant mortality is the basic driving force for increases and decreases of life expectancy.

A radical reduction of the infant mortality rate (IMR) occurred in Russia in the late 1940s and the 1950s. Between 1940 and 1956, the IMR in Russia decreased by approximately 4 times, from 200 per 1,000 to 49 per 1,000.[18] In the next decade, the IMR was cut in half to 25.5 per 1,000 in 1965 (Figure 4.5). As a result, the increase in life expectancy at birth was very large between 1938-39 and 1965--24.3 years for males and 27.1 for females (Table 4.3). Decreasing mortality at ages under 5 contributed approximately equal fractions of the improvement for males and females (16.5 and 16.8 years, respectively). The influence of mortality decline at adult ages on overall life expectancy improvements was much smaller and unequal by sex: 7.8 years for males and 10.3 years for females. Hence, during two postwar decades, Russian women gained significantly more than Russian men due to the more favorable mortality trends at adult ages.

Despite economical crises that took place in Russia over the past 15 years, infant mortality remains relatively low, however male life expectancy is very short.