Complementing other answers. Are you judging people of the past by your own modern standards?
Did a child represent a commitment, hard work or a sacrifice? Yes, but:
as said above, feeding 6 is not much more expensive than feeding 5.
Even today, people with 6 children say the same - expenses are not linear in many aspects - economies of scale with food, shared clothing, toys and books, help from the older children (e.g. no paid babysitter for the younger ones), more good willingness from people around. There is no reason for this to be less true in Victorian times.
Moreover, even with no children, keeping the house and cooking was a full time job without modern appliances.
I always find funny when modern feminists throw ready-to-cook chicken breast meat in the microwave and after 10 min they eat and complain "in the past women could not leave the kitchen! Patriarchy! oppression!". But my great-grandmother could not buy chicken meat, the only way to eat meat was to buy a live chicken (at least the shop boy would strangle it for you), and then pluck the feathers manually, open it to clean the viscera, and then start to cook - after the husband cut the wood for the wood oven. Sunday's pasta with chicken would require work since Thursday, as there were not ready pasta to buy, she had to buy flour, then mix, ferment, cut and dry the pasta into spaghetti format before cooking.
when the women married, they already knew "wife, housekeeper and mother" properly done was a full time job from day one - and unless they had money to hire servants to do the work, anything else was unthinkable. Every girlish dream of prince charming would involve this full time job, or what else? To starve? To find a pot of gold in the garden?
other expenses? medicine was mostly doctor visits and charity hospitals. There were not insurance plans paid per capita - no expensive antibiotics and vaccination, no Xray, MRI scans, no medical insurance premiums. And it was out of reach of many people anyway, does not matter how many children you have.
Few people had money to private education, even for one child. Most depended on public, church, or charity schools, or even would go with no or little formal schooling.
Today every child has a predictable price tag: (food + school + medical insurance + expensive toys ), but for most of the human story it was just another mouth and another hand - that would start to be useful quite early, not at 25 after college.
Having children was not such a hard decision as today, and many more things were clearly out of control anyway - or at least we like to think we are in control today.
one christian aspect that we lost today is the yuk-factor of contraception that was common before.
When a married couple has sex while being open to conception, they are trusting each other with their lives, by accepting the live-long commitment to a new child, and trusting the other to be around to help. Sex with contraception is just mutual pleasure, expecting love to grow without every lovemaking being a repeated act of life commitment and trust. Contraception smacks of 'un-trust' - if you really loves her/him, you do not expect to be together? To raise the children together? Don't you trust her/him? Why do you have your own plans without him/her, aren't you a married man/woman? This must have a lot to do with the astronomic level of divorce today.
Obviously they knew that withdrawal was not reliable, but condoms existed. They were not so available or well known mostly because most people would not want it.
And, which standard is saner? Past or Present?
Do you really believe in 200 years of peace, prosperity, and 1.5 child/woman?
Aren't you living in a society that can not even keep itself in existence in the long term, and criticizing past societies which survived and grew under harsher conditions?
BTW: it may be interesting to know that the catholic church does not have a definitive opinion about contraception outside of marriage. Humane Vitae only deals with contraception in the marriage context. Obviously if one is already fornicating, it is not so relevant to discuss if there is another associated sin or not.