Russian lawmakers on Tuesday voted to ban the advocacy of child-free lifestyles, in a move that is part of a broader effort by the Kremlin to reverse a falling birthrate and promote the country as a bastion of traditional values that is battling a decadent West.

The State Duma, or lower house of Parliament, unanimously approved a bill that would ban any form of “propaganda” promoting the “refusal to have children.” That would include material on the internet, in media outlets, in movies and in advertising that portrays child-free lifestyles as attractive.

Violators would be subjected to fines of up to about $4,000 for individuals and $50,000 for legal entities.

The bill has been broadly endorsed by the Kremlin and is expected to receive approval from the Federation Council, the upper chamber of Parliament, and then be signed into law by President Vladimir V. Putin.

In September, speaking about the proposed legislation, Dmitri S. Peskov, the Kremlin’s spokesman, called demography “one of the main challenges” for Russia.

“Everything that needs to be done to increase birthrates must be done,” Mr. Peskov said. “And everything that obstructs that must disappear from our lives.”