(2/25/99)

For most couples, deciding when to have the first baby is easy. But the timing on the second or third is a tougher choice. Now new research suggests some guidelines. CNN's Pat Etheridge has details.

Stuart, Mitchell and Mary Gray are like stair steps-- siblings born less than two years apart. Their mother, Lisa Gray, admits, "At one point, I did have three children in diapers and that's no fun."

No fun perhaps, but the best of all possible timing according to a new study in the New England Journal of Medicine. Dr. Bao-Ping Zhu says, "It is the best to space the interval between delivery and the next conception at about 18 to 23 months."

Researchers liken a woman's childbearing years to being an athlete in training. Dr. Zhu says, "The delivery is like running for the marathon. You don't want to have two deliveries too close together. Otherwise the body will be tired. And the birth outcomes are not likely to be good. On the other hand you don't want to wait too long either."

The authors conducted the seven-year study on more than 170,000 infants born in Utah. They found the danger in spacing pregnancies too close together or too far apart increases the risk of premature births and lower birth weights.

They suggest that doctors counsel women about their findings, and point out the benefits of having babies in close succession.

But the reality is that many other factors come into play when planning a family. And, regardless of timing, the odds for a healthy baby are high if the mother stays fit and healthy.

Perinatologist, Dr. Chip Hamner, says, "I think the best time to have another child is when it is right for you. Your work situation, your family situation, kids ... that can be just as an important decision maker as any study that gets published."

Lisa Gray says news of this study doesn't surprise her. And though she didn't plan to have her children so close together, she says it's the best, and she wouldn't have it any other way.