While improvements in contraception do play a role in birth rate decline, it should be noted that contraceptives were not generally available nor widely used in the 19th century and as a result likely did not play a significant role in the decline then.
虽然避孕措施的改善确实对出生率的下降起到了一定作用，但应该指出的是，避孕用具在19世纪并不普遍可得，也没有广泛使用，因此很可能在当时的出生率下降中没有发挥重要作用。