Thanks for your courteous response. Generally speaking it is a speculative answer. We have had one miscarriage at 16 weeks, one relatively easy pregnancy for our first child, and a slightly more complicated one with our second child although there was never an alarming possibility of death for my wife or child. And yes my wife and I are blessed with a complete agreement on these matters having received our formation in the same places. Obviously not all couples are in the same situation. 

Certainly the call to continence is not one which is heard very frequently in the current age. I would say that from all sides of the debate about such matters in the Church, even the "conservative" position, continence is rarely mentioned for fear of communicating that the Church thinks sex is dirty or strictly useful for procreation. It is a shame as continence in marriage has strong precedent in the lives of Catholic couples throughout history. 

Of course, the Holy Family is always before us...