Short answer: 6 months. The American Association of Pediatrics has just given us one more big, compelling (if exhausting) reason why. And its implications for working moms are frightening.

Here's what we already knew: The 800+ women I surveyed/interviewed felt physically and emotionally recovered right around the 6-month mark. Studies show that women who have 6 months of paid leave are less likely to develop post-partum mood disorders; they are more likely to stick with their careers for the long term; their babies are more likely to be up to date on their vaccinations.

But in case anyone (private companies, public officials...certain presidential candidates) would like any more proof of the magic of 6 months: The American Association of Pediatrics recently released new sleep guidelines: To reduce the risk of SIDS, infants should sleep in the same room as the parent(s) (but not the same bed) for....you guessed it: 6 MONTHS.

Hm. So that's 6 months of hearing every little sniffle and squeak, 6 months of having your mom radar turned up to 11 even in the wee hours, even once your baby has started sleeping through the night. Six months of being...exhausted.

I wonder, honestly, if we will see an uptick of maternal mental health issues for working women who follow these AAP recommendations. That would be a crying, wailing shame. Worse, I suspect many working moms will simply choose to ignore the guidelines...because they have to be functional on the job.

My book is full of workarounds for moms who need to be back at work before they're ready (including ways to game the whole sleep situation). But the point here is this: Mothers are more likely to follow these AAP guidelines if they don't have to be at their job the next morning.

If six months is what Baby needs, six months is what Mom needs, too.