Any parent will tell you that having a child is worth every penny ever spent and every sleepless night ever suffered. However, a newborn isn't worth extra time off work -- or so the February issue of Demography magazine reports from a study of 3,800 women and 4,500 men.

The study found that passage of a 1993 law allowing new parents up to 12 weeks unpaid leave has hardly increased leave-taking. New fathers have not taken more leaves at all, and new mothers have taken only marginally more unpaid leaves.

Now, we know y'all love your newborn children more than you love your work, so what gives? Why aren't you taking more time off to be with Mini You?

The biggest reason, not surprisingly, is money. Bringing a new life into the world is hardly the time to cut household income in half or stop it altogether. Most parents can't afford the luxury. That's a shame, because the first three months (so we hear) are "just magical." Or, "just something," anyway.

About 50% of workers in the private sector can take unpaid, job-protected leave under the '93 law. Outside the law, relatively few are given paid leave. So, if you plan to have a child and both you and your spouse want the first 12 weeks uninterrupted with the little guy, figure out how much money you'll need in order to live without income and without denting your long-term savings.

Then start to save -- living below your means if need be -- and put the savings in a higher-interest CD or another 100% safe savings vehicle. (Consider the new Motley Fool Personal Finance Workbook for tips on saving.)

Raising children is expensive, but three unbroken months with your new bundle of joy is priceless. By planning ahead and saving smartly (boss willing), you could have it.