CHICAGO - Women can maximize their chances of having healthy babies by spacing their pregnancies at least 18 months but no more than five years apart, researchers say. The researchers reached that conclusion after an analysis of 67 international studies involving more than 11 million pregnancies. The analysis found that spacing babies too close together or too far apart raises the risk of such complications as premature births and low birth weight. The findings suggest that millions of infant deaths could be avoided worldwide with better family planning, said one of the authors, Dr. Agustin Conde-Agudelo of Santa Fe de...