Nutrition is a key modifiable factor that affects birth outcomes and has long-term effects on the
health of offspring.

Patient nutrition risk and habits should be assessed early in pregnancy. Completion of a self- administered dietary questionnaire prior to seeing the clinician can be helpful. Potential problems that require attention include:

• Use of supplements
   
• Food avoidances/special diets/skipping meals
   
• Eating disorders
   
• Lack of resources for adequate nutrition
   
• Low intake of nutrient-dense foods (fruits and vegetables)
   
• High intake of added sugars and fats (fried foods, processed foods, desserts)
   
• Overweight or obesity
   
• Medical history of bariatric surgery or other conditions that cause malabsorption
   
• Substance misuse
   
• Consultation with a trained specialist in maternal nutrition, such as a registered dietitian, is recommended for women with high nutrition risk.

The incidence of pregnancy complications is higher at the upper and lower extremes of weight gain. The Institute of Medicine recommendations for weight gain during singleton pregnancy are:

• Body mass index (BMI) <18.5 kg/m2 (underweight) – weight gain 28 to 40 lbs (12.5 to 18.0 kg)
   
• BMI 18.5 to 24.9 kg/m2 (normal weight) – weight gain 25 to 35 lbs (11.5 to 16.0 kg)
   
• BMI ≥30.0 kg/m2 (obese) – weight gain 11 to 20 lbs (5 to 9.0 kg)
   

The Institute of Medicine and the Centers for Disease Control and Prevention recommend multiple-micronutrient (MMN) supplements (commonly called multivitamin supplements) for pregnant women who do not consume an adequate diet or may have malabsorption. Well- nourished women may not need MMN supplements, but in the absence of careful evaluation by a nutritionist, it is prudent to recommend them. At a minimum, the daily MMN supplement should contain key vitamins/minerals that are often not met by diet alone