For most families and single individuals, having a child will be the most financially taxing decision to occur in their lifetimes, especially if they have more than one child. Staying out of significant debt and being financially secure does seem to be closely correlated with access to contraception.
In the United States, 71% of women with access to birth control say that it does allow them to be much more confident in their financial situation. This includes having lower debt totals, more disposable income, greater overall income, and reduced living expenses.
Decreasing the amount of debt that both single and married mothers have to live with does seem to have a significant positive impact on their lives, and the lives of their children. Kids with healthier home lives tend to do better in school and stay on the right side of the law later in life.
Expanding access to birth control would likely have a positive impact on the nation at large, while giving individuals and couples a way to plan a family without leaving much up to chance.