What are the nutritional recommendations for pregnant individuals?

Nutritional Recommendations for Pregnancy

All pregnant women should consume a nutrient-dense diet emphasizing whole foods (fruits, vegetables, legumes, whole grains, fish, nuts, seeds) while avoiding processed foods, fatty red meat, and sweetened beverages, combined with essential supplementation of folic acid (400 µg/day or 5 mg/day if obese/diabetic), iron (30 mg/day in second and third trimesters), and an additional 300 kcal/day after the first trimester. 1, 2, 3

Essential Supplementation

Folic acid is the highest priority supplement, starting before conception and continuing through at least the first trimester at 400 µg/day for all women, or 5 mg/day if obese or diabetic, to prevent neural tube defects and congenital abnormalities. 1, 2

Iron supplementation of 30 mg/day is required during the second and third trimesters to prevent maternal anemia and support increased blood volume. 1, 2 Supplement use reduces the prevalence of inadequate iron intake from 95.3% to 80.3% among pregnant women. 4

Additional supplementation to consider:

• Zinc supplementation for women with low pre-pregnancy weight and low plasma zinc levels, as average intake (11 mg/day) falls below the RDA (15 mg/day), leading to higher infant birth weight. 1, 2
• Calcium supplementation of 1.0-1.5 g elemental calcium daily as calcium carbonate in divided doses (no more than 500 mg per dose) to prevent preeclampsia in populations with low dietary calcium intake. 2, 5
• Iodine should be included in prenatal supplements due to increasing deficiency rates. 5
• Vitamin C for women who smoke to lower the incidence of asthma and wheezing in children. 5

Energy and Macronutrient Requirements

No additional calories are needed in the first trimester unless the woman begins pregnancy with depleted body reserves. 1, 6

Add 300 kcal/day during the second and third trimesters to support maternal blood volume expansion, breast and uterine growth, placental development, fetal growth, and amniotic fluid. 1, 2, 6

Protein requirements increase significantly during pregnancy:

• Early pregnancy (~16 weeks): 1.2 g/kg/day 1
• Late pregnancy (~36 weeks): 1.52 g/kg/day 1, 2

This represents a substantial increase from older recommendations of 0.75 g/kg/day plus 10 g/day. 1, 6

Dietary Composition and Quality

Base your diet on nutrient-dense, whole foods including fruits, vegetables, legumes, whole grains, healthy fats with omega-3 fatty acids (nuts, seeds, fish), and lean protein. 1, 3 This approach provides adequate micronutrients naturally and is less likely to promote excessive weight gain. 1

Strictly limit or avoid:

• Processed foods, fatty red meat, and sweetened foods and beverages 1, 3
• High-fat foods including fried foods, full-fat dairy, butter, cream sauces, and fast food 6

Avoid completely:

• Alcohol - no amount is considered safe during pregnancy 1, 2
• Vitamin A in retinol form during the first 12 weeks due to teratogenic risk 1, 2
• Raw animal products and soft cheeses to prevent foodborne illness 1
• Limit caffeine to no more than 200 mg per day 1, 2

Meal Distribution and Timing

Distribute carbohydrates throughout the day into three small-to-moderate meals and 2-4 snacks. 1, 6 This pattern prevents prolonged gallbladder stasis and maintains stable blood glucose levels. 6

An evening snack is mandatory to decrease overnight hypoglycemia and fasting ketosis, particularly for insulin-treated women. 1, 6 This also maintains gallbladder function and prevents bile concentration. 6

Weight Gain Targets

Weight gain recommendations vary by pre-pregnancy BMI:

• Underweight women (BMI <19.8): up to 18 kg total 1
• Normal-weight women: 1.4-2.3 kg in the first trimester and 0.5-0.9 kg/week during the second and third trimesters 1
• Overweight women: gain at less than 50% of the normal-weight rate 1
• Obese women (BMI >30): limit total weight gain to 5.0-9.1 kg 1

First-trimester gain is the strongest predictor of adverse outcomes, emphasizing the importance of early intervention. 3

Critical Pitfalls to Avoid

Never prescribe hypocaloric diets below 1,200 calories/day. 1, 6 Such diets result in ketonemia and ketonuria, which have been associated with lower intelligence scores in offspring at ages 2-5 years. 1, 6

Monitor for ketones using daily food records, weekly weight checks, and ketone testing to ensure women are not under-eating to avoid insulin therapy. 1, 6

Avoid diets that severely restrict any macronutrient class:

• Ketogenic diet (lacks carbohydrates) 7, 3
• Paleo diet (dairy restriction) 7, 3
• Any diet characterized by excess saturated fats 7, 3

Be aware of supplement risks: While supplement use improves nutrient adequacy, 33.4% of pregnant women exceed the Tolerable Upper Intake Level for folic acid and 27.9% for iron when using supplements. 4 Almost all pregnant women (95.0%) are at risk of excessive sodium consumption. 4

Special Populations

Women with Diabetes

Referral to a registered dietitian nutritionist is essential to establish a food plan, insulin-to-carbohydrate ratio, and weight gain goals. 7 Pregnant women with diabetes must eat consistent amounts of carbohydrates to match insulin dosage and avoid hyperglycemia or hypoglycemia. 7

Evaluate carbohydrate quality carefully. Studies show that diets of pregnant women with diabetes are often characterized by high-fat, low-fiber, and poor-quality carbohydrate intakes, with inadequate fruit and vegetable consumption and one in four at risk for micronutrient deficiencies. 7

Post-Bariatric Surgery Patients

Require nutritional screening every trimester including ferritin, folate, vitamin B12, calcium, vitamin D, and vitamin A levels, with supplementation adjusted accordingly. 1, 2

Monitor vitamin B12 levels every trimester in at-risk populations, as severe deficiency can occur in exclusively breastfed infants born to mothers who underwent gastric bypass. 2

Common Nutrient Inadequacies

Despite supplementation, significant proportions of pregnant women fail to meet recommendations for:

• Magnesium (47.5%) 4
• Vitamin D (46.4%) 4
• Vitamin E (43.3%) 4
• Iron (36.2%) 4
• Folate (16.4%) 4
• Vitamin A (15.5%) 4
• Calcium (12.9%) 4
• Vitamin C (11.5%) 4
• Vitamin B6 (11.5%) 4
• Zinc (10.9%) 4

This underscores the importance of dietary counseling focused on nutrient-dense whole foods rather than relying solely on supplementation. 4