03/24/2013 10:38 am ET Updated May 20, 2013

What Your Children Cost You in Sleep

Every parent knows that having children means losing sleep. This begins with your pregnancy and extends through the course of your childrens' early years, and can exact a serious toll on your physical and mental health.

Once you're past the every three-hour feedings and your baby is sleeping through the night, you may think you're home-free except for the occasional middle of the night illnesses that require attention.

According to a study published in the American Journal of Epidemiology last month, this isn't the end of your lost sleep chapter in life. The study gathered data from 833 people and followed them for 19 years.

Here is what they found: Parents lose 13 minutes of sleep each night for each child under age two. For each child between ages two and five, you lose nine minutes each night. If your child is between ages six and 18, you only lose four minutes each night.

Adult children over 18 didn't cause sleep loss to parents. Some would argue with that finding and wonder how this could be the case. Perhaps whatever problems the 20-year-old children experienced, the parents somehow learned to detach themselves enough to still sleep well.

These numbers may seem insignificant. After all, what is four minutes of less sleep? That's less than the equivalent of pushing the snooze button on your alarm clock one more time. If you only have one child over age six, then you're losing roughly 20 minutes over a five-day work week. Then on the weekend if you sleep in an extra 20 minutes, you've caught up for the week.

It becomes more problematic for parents with multiple children. Suppose you have three kids ages one, three and five. According to this study, you're sleeping 36 minutes less each night. Thirty six minutes still may not sound excessive. But to put it in practical terms, imagine if you need to wake at 6 a.m. for work -- how easy is it for you to wake up 30 minutes earlier?

By the end of the five-day work week, you now have a sleep deficit of two and a half hours. It's considerably harder to make up for two and a half hours of lost sleep on a weekend. Add a nightmare or stomach flu to the equation, and your sleep loss totals can be even greater.

Doubtless, these numbers aren't going to apply to everyone. You may have the champion sleeper who is out like a light every night at 7:30 p.m. and rarely gets sick. But this is probably the atypical situation and unlikely to be the case if you have multiple children.

This is the first study of this kind to quantify sleep loss in parents over a long period of time, and can help you take proactive measures to plan your evening with the goal of going to bed earlier. If it seems impossible to get into bed 1/2 hour earlier each night, doing so even 15 minutes earlier can make a difference in reducing your sleep debt at the end of the week.

For more by Tracey Marks, M.D., click here.

For more on sleep, click here.