Christians, by the data, are middle of the road re: large families by religion:
Pew Research Center analyzed data on six religious groups – Christians, Muslims, Hindus, Buddhists, Jews and people with no religious affiliation.
Globally, the average Muslim lives in the biggest household (6.4 people), followed by the average Hindu (5.7), Christian (4.5), Buddhist (3.9), “none” (3.7) and Jew (3.7)
Many of the pronatalist altruists are more rich than religious; eg Musk and others:
https://www.theguardian.com/lifeandstyle/article/2024/may/25...
https://news.ycombinator.com/item?id=40473060
It doesn't seem that a Christian worldview is neccesary for many with large families.