I am NOT PRO LARGE FAMILIES, I think that sort of thinking is not healthy for the world as a whole.
From the beginning, civilisations have perished because of the following factors combining;
1 Over population for the available resources
2 Timber depletion because it is used for building and heat.
3 Water is depleted by overuse or climate altering, because of population growth or depletion of trees, grasses etc
4 Soil becomes depleted by lack of improvement, erosion by wind and water adds to the damage, damage and food shortages occur.
4 Famine or war hits.
5 community degrades or is forced to move, to start the cycle again.
Its been repeated all over the world.
300- 1000 years seems the limits generally.
Currently science is helping with food, but land is being degraded everywhere by human activity.
Its built on, poisoned, eroded away or lost its capacity to grow anything.
I doubt science and technology can prevent it in the long run.