Pre-Pregnancy Nutrition and Requirements

Pre-Pregnancy Nutrition

• Pre-pregnancy weight is crucial for a healthy pregnancy.
• Overweight and obese women have an increased risk of:
  • Gestational diabetes
  • Pregnancy-induced hypertension
  • Pre-eclampsia
  • Congenital defects
  • Abnormal labor
  • Cesarean operation
  • Infants born preterm are less likely to survive
  • Heart defects
  • Neural tube defects
• Pre-pregnancy BMI between 19.8 and 26.0 kg/m2 is ideal.
• Recommended actions before conception:
  • Maintain a healthy weight by gradual weight gain or loss (no more than 1-2 pounds/week).
  • Engage in regular physical activity.
  • Stop drinking alcohol.
  • Quit smoking.
  • Consume a highly fortified breakfast cereal with 100% DV for folate, increase intake of dark green leafy vegetables or take a vitamin supplement with 400 μg/day of folic acid.

Nutritional Requirements During Pregnancy

• Pregnancy lasts 38 to 42 weeks, divided into trimesters:
  • First trimester: conception to week 13
  • Second trimester: week 14 to week 27
  • Third trimester: week 28 to week 40
• Embryonic stage: approximately day 15 to week 8. After this stage, the developing baby is called a fetus.
• Critical periods occur during pregnancy when tissues and organs differentiate and mature. Proper building blocks (proteins, carbohydrates, lipids) are essential for proper development during these periods.

Maternal Physiological Changes in Pregnancy

• Cardiovascular changes:
  • Peripheral vasodilatation results in decreased systemic vascular resistance, leading to increased cardiac output (30-50%) and heart rate (10-20%).
  • Mean arterial blood pressure decreases (10%).
• Respiratory changes:
  • Increased oxygen demand by 20%.
  • Hyperventilation and elevation of the diaphragm cause breathlessness.
  • Improved tissue and oxygen availability to the placenta.
• Urinary tract and renal function:
  • Increased blood flow (60-70%).
  • Increased glomerular filtration (50%).
  • Enhanced clearance of most substances.
  • Reduced plasma creatinine, urea, and urate levels.
  • Normal glycosuria.
• Gastrointestinal system changes:
  • Spongy gums.
  • Relaxed lower esophageal sphincter (heartburn).
  • Reduced gastric secretion and delayed gastric emptying.
  • Nausea and vomiting.
  • Increased appetite.
  • Changes in taste.
  • Reduced intestinal secretions.
  • Decreased intestinal motility.
  • Decreased emptying time of the gallbladder.
  • Relaxed intestinal musculature (constipation).
• Endocrinological changes:
  • Marked increase in prolactin concentration (acts after delivery).
  • Development of insulin resistance.
  • Minor changes in thyroid function.
  • Enhanced transplacental calcium transport.
  • Increased corticosteroid and aldosterone concentrations.
  • Increased angiotensin and renin levels.

Metabolic Changes and Adaptive Responses During Pregnancy

• Changes in maternal hormone secretions lead to altered utilization of carbohydrates, fats, and proteins.
• Human chorionic somatomammotropin (placental hormone) encourages maternal tissues to use lipids for energy production, increasing glucose and amino acid availability for the fetus.
• Hormonal changes conserve maternal lean tissues, preventing their use for energy or amino acids for the fetus.
• Adaptive responses meet the increased nutrient demands of the mother and fetus.
  • Enhanced absorption of iron and calcium.
  • Improved absorption of other minerals (copper and zinc).
  • Reduced urinary excretion of certain nutrients (riboflavin, taurine).
  • Increased aldosterone secretion leading to sodium reabsorption and fluid retention.

Exercise During Pregnancy

• Regular physical activity is healthy for both mother and baby.
• Helps prevent excessive weight gain and alleviate discomforts such as constipation, water retention, and fatigue.
• Recommended activity: 30 minutes of moderate intensity activity most days of the week.
  • Walking, swimming, low-impact aerobics, and stationary bicycling.
• Avoid contact sports and activities involving sudden jerking or bouncing movements.

Weight Gain During Pregnancy

• Appropriate weight gain is vital for maternal and infant outcomes.
• Optimal weight gain depends on pre-pregnancy BMI:
  • Normal pre-pregnancy BMI (18.5-24.9): 11.5 to 16 kg weight gain.
  • Low pre-pregnancy BMI (below 18.5): 12.5-18 kg weight gain.
  • High pre-pregnancy BMI (over 30): 5-9 kg weight gain.
• Weight gain includes:
  • Weight of the fetus, placenta, amniotic fluid, uterus, breast, and expanded blood volume.
  • Any additional weight gain is an energy reserve for the mother.

Determinants of Gestational Weight Gain

• Maternal factors:
  • Sociodemographic (age, parity, ethnic background, socioeconomic status).
  • Nutritional (BMI, lean body mass, body fat).
  • Genetic.
  • Health/Illness (diabetes, hypertension, chronic disease, infections).
  • Environmental (geography, climate).
  • Behavioral (attitudes, stress, anxiety, smoking, alcohol, drug use).
• Prenatal care also plays a role.
• Weight gain grids track weight gain by week of gestation and allow individualized monitoring for women with varying pre-pregnancy BMIs.
• If gaining too little or slowly, encourage 5-6 small meals a day instead of 3 larger meals.

Dietary Assessment During Pregnancy

• Early dietary assessment through a food history or frequency questionnaire is important.
• Pregnant women do not need to "eat for two".
• A healthy, varied diet rich in nutrients is crucial for both mother and baby.
• The fetus receives all nutrients through the placenta, so dietary intake must meet the needs of both the mother and the developing baby.
• Maternal nutrient stores are essential for fostering fetal development and lactation.

Energy Requirements During Pregnancy

• Adequate energy intake is necessary for a healthy, full-term infant of appropriate size and body composition.
• Increased energy requirements during pregnancy:
  • Second trimester: +340 kcal/day.
  • Third trimester: +450 kcal/day.
• Energy requirements increase due to:
  • Increased basal metabolic rate.
  • Energy deposition in new tissues (fetus, placenta, amniotic fluid).
  • Growth of existing maternal tissues (breast, uterus).
  • Extra maternal fat deposition.

Protein Requirements During Pregnancy

• Protein RDA for pregnancy: 71 g/day (+25 g/day compared to non-pregnant women).
• Pregnant women can easily meet their protein needs through:
  • Meats
  • Milk products
  • Protein-rich plant foods (legumes, nuts, whole grains, seeds).
• Protein supplements should be avoided during pregnancy as they may be harmful to the developing fetus.

Essential Fatty Acids During Pregnancy

• Long-chain fatty acids are crucial for fetal growth and development.
• The brain relies heavily on omega-3 and omega-6 fatty acids for growth, function, and structure.

Diet-Related Conditions During Pregnancy

• Anaemia during pregnancy:
  • Most cases are caused by iron deficiency.
  • Other causes: folate deficiency, blood loss, inherited conditions.
  • Complications in the mother: breathing difficulties, fainting, fatigue, tachycardia, palpitations, reduced resistance to infection, risk of hemorrhage before or after birth.
  • Complications in the fetus: growth retardation, pre-term delivery, low birth weight, reduced fetal iron stores leading to IDA in infancy.
• Treatment for iron deficiency anaemia:
  • Oral iron supplements prescribed with caution due to side effects (nausea, constipation) and nutrient interactions (calcium, zinc, copper).
  • Combining iron-rich foods with iron supplements is ideal.
• Leg cramps during pregnancy:
  • Magnesium supplementation may relieve leg cramps.
  • Pregnancy and lactation can cause secondary magnesium deficiency.

High-Risk Pregnancies

• Characterized by factors that increase the likelihood of complications:
  • Premature delivery
  • Difficult birth
  • Retarded growth
  • Birth defects
  • Early infant death
• Low-risk pregnancies: normal outcome is likely.
• High-risk pregnancy conditions:
  • Diabetes:
    • Pre-existing diabetes: pre-pregnancy control is crucial.
  • Hypertensive disorders:

This quiz covers essential pre-pregnancy nutrition guidelines and the importance of maintaining a healthy weight before conception. It also highlights nutritional requirements during pregnancy, focusing on actions to take for a healthier pregnancy outcome. Test your knowledge on the recommended dietary practices and their implications for maternal and infant health.