The ideal weight gain or energy intake for an individual woman cannot be determined from research studies. Current guidelines for maternal gain, however, combined with individualized assessment and follow-up, can provide the clinician and the pregnant women with a meaningful target and plan for achieving a healthy weight gain. For some women, increased amounts of maternal weight gain may improve fetal growth prenatally and therefore improve fetal health. For other women, high gains, or even gains within the recommended range, may enhance fetal growth to the point where labor complications, operative deliveries, permanent maternal obesity, and other health problems may occur. Balancing the health benefits and risks of maternal weight gain is a challenge that we will continue to face in the future.