the leading factor in birthrate are tradition, the family unit being principle, promoting babies and marriage, instead of sexuality, community, normally religion and an education, it's okay it's healthy, incentives aiding birth, cheaper housing and infrastructure, often requiring a proactive workforce. industrialisation, causes population booms.  in answer to the topic. no contraception, no regulations on childmarriage, and often the amount of wives. divorce is not promoted as a norm. neither is adverse sexuality.
United Kingdom