Ready for another baby? No one can answer that question but you, and boy, is it a tough one.

Some say it's even harder than deciding whether to have a first child. You're not just talking about having a baby, you're talking about changing a family. With each new child, you have to think about how that baby will affect your lifestyle, finances, work, relationships, and, of course, your other kids. And if you listen to the word on the street, growing your family by one means more than double the work for you.

Of course, just about everyone – from doctors and scientists to your friends and neighbors – has an opinion on perfect baby timing and the ideal family size. Weigh the pros and cons and then make your own decision. To talk with others about this complicated issue, you can visit our Community or specifically our groups for large families and parents of only children.

Read on to learn more about what to consider before welcoming a new baby into your life.

When's the best time to have another?

For many people the decision to have another child is more about when than whether. And plenty wonder if there's an ideal interval between children – for the adults' sake and the kids'. Is it best to have children one right after the other so they can play together and you get all your childrearing done in the shortest time, or is it better to "space" them to make sure everyone gets enough attention and care?

Researchers have tried to address this question, and while they can't say definitively that every woman should wait two to three years between births, many studies do settle roughly on that time frame. And so do most families: According to the Alan Guttmacher Institute, the average interval between first and second births is about 30 months for American women. Here's a rundown of the research on baby spacing:

• Timing pregnancies less than 18 months or more than five years apart could raise the odds of the second baby being born prematurely, at low birth weight, or small for gestational age, according to a study in the Journal of the American Medical Association. With too short an interval, researchers theorize, the problem may be that a mother's body needs more time to recover from the stress and depleted nutrients of the first pregnancy; with longer spacing, the problem could be that fertility gradually declines after a woman delivers.

• Waiting 18 to 23 months after the birth of your last child before conceiving another seems best for the new baby's health, according to a study published in the New England Journal of Medicine. Doctors found that babies conceived less than six months after the birth of a previous child are 40 percent more apt to be born prematurely or underweight. And those conceived more than ten years after the prior sibling face about double the risk of preterm birth.

• A similar study at the University of California in San Francisco found that the ideal interval between babies is 24 to 35 months. Babies conceived sooner had a higher incidence of low birth weight.

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