Starting (or extending) a family will invariably have an impact on all areas of your life, in some shape or form. In many cases, the question of "Can I afford to have a child (or more children)" can be a deciding factor before conceiving a baby. The costs involved with having a baby - purchasing clothing, buying baby equipment, paying for occasional or permanent childcare as well providing education and health care, places an ongoing financial commitment for possibly 20 years (or longer!) It is estimated that most parents will spend at least 20% of their income (or pension) on child-related expenses, regardless of how much they earn or receive in benefits. If an economic rationalist analysed the financial 'investment' of having a child, they would say they were a financial loss!
However, children are not commodities, and we do not have them because they represent a 'good investment', but you may want to put some thought into what you want for your child(ren) and how you intend to support them and yourselves, especially during the early years before your child starts school, and needs to be cared for constantly.
For one (or both) potential parents, the questions of who will work, how long they will work for before the baby is born, who will return to work after the birth (and when) will all be issues that need to be thought about, or discussed. For parents who are unemployed, looking into unemployment benefits, family and/or single mother's benefits, housing allowances and childcare rebates (depending on the country you live in and what your state or federal government will provide) can also help you to plan your financial survival.
Careful financial planning will be very important for single parents, as it will be for couples dropping from two wages to one. If both parents intend to return to work, then planning for the added cost of quality
childcare (if you don't have a relative or friend who can help out) will need to be considered.