The counter argument was made in Elizabeth Warrens book The Two Income Trap where her research showed that the single income family of the 1970’s had more disposable income than the two income family of the 90’s after adjusting for housing, healthcare, transportation and childcare and showed that the majority of those expenses were primarily driven by children.
A household with children has less ability to make trade offs in the big four than a household without children. For example affordable schools and childcare may dictate more expensive or more distant housing.
The result is that children have a disproportionate impact to discretionary income beyond immediate needs for food, shelter and clothing. If you consider children as just another discretionary way of spending income people in many cases will make the rational choice to spend less on children if the cost is vastly increased.
In other words if the choice is between a minivan and instant coffee and a Mercedes and Starbucks many women may rationally choose the later.
If children were like any other discretionary purchase this wouldn’t be a problem but children are also a societal asset (or liability). Current public policy in many countries has shifted to privatizes more of the costs while socializing the benefits.
For example Social Security benefits is a pay—as-you-go program but there are no adjustments to benefits based on the economic value of the children that a household contributed to the current generation that is paying it. If the costs of raising those children were fully socialized it wouldn’t be an issue but otherwise it is a transfer of income from those who raised children to those who did not.