Usual weight, weight change, and attitudes toward weight may influence the mother's pattern of weight gain during pregnancy.

Preoccupation with weight, widely fluctuating weight, or excessive exercise or dieting signals the need to assess for a potential eating disorder. Most women can alert the health care provider to large changes in weight even if they do not know their prepregnancy weight. Some women need special guidance to establish healthful weight gain goals for pregnancy Because of their special concerns about body image, adolescents usually benefit from such guidance.

Women who have poor appetites, who skip meals often, or who are purposely limiting their food intake may eat too little food to support optimal weight gain and fetal growth during pregnancy Women whose intake of food or fluids is minimal for a number of days because of lack of appetite, nausea, and/or vomiting may develop dehydration and ketosis. Usually, occasional nausea, vomiting, or loss of appetite is not a medical or nutritional concern. Almost all women will be free of gastrointestinal disease. However, an occasional woman will have a condition that requires active medical assessment and intervention. Women may need reassurance about their lack of ability to eat normally.

Women on special diets for medical conditions may need assistance from a dietitian to modify food intake in support of their own health and a healthy pregnancy. Women who omit a major food group from their diets may have inadequate intakes of nutrients supplied by that food group.