Complex sentence: Japan had a postwar baby boom between 1947 and 1949, however, the law of 1948 led to an easy access to abortions, followed by prolonged period of low fertility, resulting in the aging population of Japan.
Split into simpler sentences: Japan had a postwar baby boom between 1947 and 1949. However, the law of 1948 led to easy access to abortions, followed by a prolonged period of low fertility, resulting in the aging population of Japan.