Editorial: [Hot topic: Weight Gain Management and Nutritional Education Throughout Pregnancy (Guest Editor: Hiroko Watanabe)]

Overweight and obesity have become a serious global public health issue in the world. More than one third of the reproductive age women are overweight. Adequate gestational weight gain contributes to better perinatal short- and long-term health outcomes in both mother and infants. In women of reproductive age, high prepregnancy BMI, overweight and obesity, are risk factors for adverse pregnancy outcomes, such as gestational diabetes, preeclampsia, cesarean delivery, and having a macrosomic infant. On the other hand, some industrialized countries face rising rates of underweight women of reproductive age. Low prepregnancy BMI and low gestational weight gain are associated with increased risk of low birth weight and small gestational age infants. Animal studies suggest that a combination of undernourishment in utero and normal or high levels of nutrients in the neonatal period plays a critical role in connecting a low birth weight with obesity in later life. In 1990, the IOM issued new guidelines for pregnancy weight gain. It has been the standard for weight gain and is followed worldwide by obstetricians and midwives in many countries. In a large sample study, only 34 percent of women gained weight within, and nearly 40 percent of women gained weight above the recommended IOM range. This standard has been slightly changed since 1990. Pregnancy can be an opportune time to improve nutrition, and presents an ideal time for health promotion activities. Some studies reported that pregnant women do not have an opportunity to get adequate and appropriate nutrition education for antenatal care. Most of them expect advice on general dietary improvements, with the remainder seeking advice on helping to promote their quality and quantity of nutritional intake. All women of reproductive age should be encouraged to follow the government recommendation and eat a well-balanced diet. Health care providers need to ensure that pregnant women are aware of the positive and negative effects of poor maternal nutrition status. We need to discuss the effective weight gain management and nutritional education throughout pregnancy to improve both maternal and infant's health.