Nutrition in Pregnancy & Lactation

Nutrition in Pregnancy & Lactation Pregnancy and Physiological Changes ⇒ Pregnancy triggers significant physiological and biochemical adaptations that ensure fetal development and maternal health. Key Body Changes During Pregnancy ●​ ●​ ●​ ●​ ●​ The development and growth of the feto-placental unit Increased maternal blood volume Increased adipose tissue Decreased gastrointestinal motility Breast enlargement to prepare for lactation Increased Energy Demands ●​ ●​ Pregnant women must adjust their caloric intake to sustain the growing fetus: These increased requirements depend on a number of factors: ○​ Preconception BMI ○​ Maternal development stage (adolescent vs adult) ○​ Gestational age of the pregnancy ■​ First trimester: No additional caloric intake is needed, weight gain should be minimal ■​ Second trimester: An extra 340 kcal/day is recommended. ■​ Third trimester: An extra 452 kcal/day is required. Obstetric History and Maternal Risk Factors ⇒ A detailed obstetric history helps predict nutritional risks and guide care. Relevant Obstetric History Factors: ●​ ●​ ●​ ●​ ●​ ●​ Weight gain patterns from prior pregnancies Previous complications such as: Gestational diabetes Preeclampsia/eclampsia Anemia and pica Maternal risk factors for nutrients deficiencies: ○​ History of eating disorders or metabolic diseases ○​ Absorption disorders ○​ PKU ○​ Diabetes Short Pregnancy Intervals and Nutrient Depletion ●​ ●​ A pregnancy interval of less than one year increases the risk of maternal nutrient depletion. Consequences include preterm birth, intrauterine growth restriction (IUGR), and maternal morbidity. Weight Gain Recommendations ⇒ Weight gain during pregnancy is crucial for fetal health, but excess or inadequate gain can be harmful. ⇒ Attributable to Increases in the mother’s tissue + Feto-placental growth within the uterus ⇒ Most weight gain should occur in the second and early third trimesters (18 to 30 weeks) ⇒ Adequate weight gain in the 2nd trimester seems to be predictive of fetal and neonatal weight ●​ ●​ Weight Gain by Pre-Pregnancy BMI ○​ Underweight (BMI < 18.5): 28–40 lbs ○​ Normal (BMI 18.5–24.9): 25–35 lbs ○​ Overweight (BMI 25–29.9): 15–25 lbs ○​ Obese (BMI > 30): 11–20 lbs Twin Pregnancy Weight Gain ○​ Normal BMI: 37–54 lbs ○​ Overweight BMI: 31–50 lbs ○​ Obese BMI: 25–42 lbs Underweight Preconception BMI ●​ ●​ Women with low preconception BMI (<18.5) are at risk for delivering low-birth weight infants (< 2,500g; < 5lb 8 oz) Inadequate weight gain (< 2lb/month during 2nd/3rd trimesters) is associated with LBW infants, IUGR and fetal complications Overweight and Obese Preconception BMI ●​ Women with a high preconception BMI (>26) are at risk for: ○​ Gestational diabetes ○​ Gestational HTN ○​ Thromboembolic events ○​ Preeclampsia ○​ Delivering macrosomic infants (> 4,000g; 8lb 13oz) ○​ Increased risk for cesarean delivery ●​ ●​ BUT - We want to limit weight gain, but not severely restrict caloric intake Severe caloric restriction can lead to inadequate intake of important macro and micronutrients ○​ Example: severe restriction of caloric intake paired with severe restriction of carbs can result in ketosis (which in diabetic women) can be detrimental to the fetus Maternal Nutrient Needs ⇒ Each nutrient plays a crucial role in fetal development and maternal health. Macronutrients ●​ ●​ Protein: Increased from 46 g/day to 71 g/day to support fetal growth. Carbohydrates and fats: Requirements remain stable unless gestational diabetes is present. Key Micronutrient Needs Nutrient Folic Acid Calcium Iron Recommended Daily Allowance (RDA) Key Info Pregnant Women: 600 µg Women of childbearing age: 400 µg ●​ Nonpregnant females: 1,000 mg ●​ Pregnant females (age 14-18): 1,300 mg ●​ Pregnant females (age 19-30 yo): 1,000 mg ●​ Pregnant females (age 31-50 yo): 1,300 mg 27 mg/day during pregnancy ●​ Prevents neural tube defects (NTDs) ○​ NT development and closure is complete by 18-26 days after conception (often before women know they are pregnant) ●​ Folic acid deficiency is the most common vitamin deficiency during pregnancy ●​ Studied suggest long-term use of oral contraceptives inhibits folate absorption and enhances degradation in the liver ●​ Critical for women of childbearing age to continue folate supplementation during oral contraceptive use ●​ Supports fetal bone development ●​ Prevents gestational hypertension ●​ ●​ Iron deficiency anemia has been associated with an increased risk of: Maternal and infant death Preterm delivery Low-birth weight babies / small for gestational age Negative consequences for infant brain development/function Iron is known to cause GI SEs - Constipation Screening for iron deficiency done in 1st trimester Not all prenatal vitamins contain iron! Vitamin D required to absorb calcium sufficiently Vitamin D deficiency during pregnancy has been associated with: ○​ Skeletal anomalies ○​ Fractures ○​ Congenital Rickets ○​ More common in vegetarians and those with limited sun exposure Prevents constipation and promotes gut health Increased intake of high fiber foods (vegetables, whole grains and fruit) is encouraged to prevent and treat of constipation Constipation is due to hormonal changes + iron supplementation Substantial fluid intake is required in order to maintain blood flow to vital organs Inadequate fluid intake is associated with ○​ Premature uterine contractions ○​ Preterm delivery ○​ IUGR ○​ Hypertensive disorders of pregnancy During the 1st trimester, excessive caffeine intake is shown to increase the risk of miscarriage ○​ ○​ ○​ ○​ ●​ ●​ ●​ ●​ ●​ Vitamin D Fiber 600 IU/day (pregnant or non pregnant) No specific RDA ●​ ●​ ●​ ●​ ●​ Fluids Caffeine At least 64 oz (8 cups) Limtied to < 200 mg/day ●​ Common Nutrition-Related Pregnancy Complications ⇒ Many pregnancy-related issues have nutritional components. Pregnancy Complication Nausea & Vomiting (Morning Sickness) Heartburn & Indigestion Constipation Gestational Diabetes Mellitus (GDM) Cause Caused by elevated HCG levels. Results from reduced esophageal sphincter pressure - gastric reflux, decrease motility and organ displacement/decreased gastric capacity. Management Strategies: ●​ Eat small, frequent meals, low-fat meals ●​ Avoid strong food odors. ●​ Opt for room-temperature foods. ●​ Drink fluids between meals, not with meals. ●​ Avoid caffeine, citrus, spicy foods. ●​ Wait 1-2 hours after meals before lying down. Caused by slower GI motility and increased water absorption. ●​ Increase fluid intake ●​ Increase daily fiber intake or add a psyllium fiber supplement (Metamucil) ●​ Increase consumption of fruits and veggies ●​ Participate in moderate physical activity Glucose intolerance with onset or first recognition during pregnancy -​ Occurs in 2–10% of pregnancies. -​ Increases risk of macrosomia (large baby) and C-section. -​ All pregnant women should be screened for GDM at 24-28 weeks -​ Screening tool: 1 and 3 hour glucose tolerance tests ●​ Monitor blood glucose. ●​ Maintain 40-45% carbohydrate intake distributed across meals. ●​ If necessary, use insulin therapy. ●​ Women with GDM become normoglycemic, but are at an increased risk of developing DM2 later in life -​ The 3-hour test only is performed if the 1-hour is failed Lactation and Breastfeeding ●​ Lactation: The process of developing the ability to secrete milk ○​ Initiated by the abrupt decrease in progesterone and estrogen following childbirth ○​ Hypothalamus in turn stimulates the release of prolactin from the anterior pituitary gland and oxytocin from the posterior pituitary gland ■​ Prolactin stimulates milk production in the breast ■​ Oxytocin stimulates letdown (the ability of the alveolus to eject milk) Breast Milk Composition ●​ ●​ ●​ ●​ ●​ Breast milk has components that work to minimize the risk of infection in the nursing infant ○​ Leukocytes ○​ Immunoglobulins ○​ Lysozymes ○​ Lactoferrin ○​ lactadherin ○​ Hormones ○​ Prostaglandins Fat ○​ Total amount of fat in breast milk is constant, but its composition changes during the feed ■​ Initially has a lower fat content and higher water content ■​ Following the first letdown reflex, BM becomes higher in fat and calories ○​ Fat content provides 50% of an infant’s total energy requirements Protein ○​ Breast milk contains casein and whey proteins ■​ Whey: 70% of the total protein ■​ Casein: 30% ○​ The total protein concentration is relatively low; but it is the optimal concentration for infant nutrition Carbohydrate ●​ ●​ ●​ ●​ ●​ ○​ Primary carbohydrate source in breast milk is the disaccharide lactose Colostrum ○​ Produced during late stages of pregnancy, and highest in conc. during first few days of lactation ○​ High in protein, immunoglobulins, and beta-carotene, Na, K, Cl, fat soluble vitamins, minerals and hormones ○​ 16 kcals/ounce Transitional milk: ○​ Produced 1-2 weeks postpartum ○​ Higher in fat and lactose ○​ Lower in protein and minerals Mature milk: ○​ Produced by the 15th day of lactation through the end of lactation ○​ It is composed of emulsified fat and lactose ○​ Ensures optimal nutrition ○​ Contains 20–22 kcal ounce Vitamin D ○​ Some breastfed infants are at risk for Rickets, caused by a vitamin D deficiency because breast milk contains only small amounts of this nutrient ○​ The American Academy of Pediatrics recommends that all exclusively breastfed infants receive 400 IU of vitamin D daily by 2 months of age ● Vitamin K ○​ Breast milk only contains small amounts of vitamin K ○​ However, supplementation is generally unnecessary ■​ Most infants receive an injection of vitamin K immediately following delivery Benefits of Breastfeeding ●​ ●​ For the infant: ○​ Breastfed infants are hospitalized less during the first 6 months of life ○​ Reduces the incidence and severity of: Diarrhea, Bacteremia, Bacterial meningitis, UTIs ○​ Protective effects against autoimmune diseases (e.g., Type 1 Diabetes, IBD, allergic diseases) ○​ Reduces SIDS risk. For the mother: ○​ Aids in postpartum weight loss ⇒ Earlier return to pre-gravid weight ○​ Decreases adipose tissue accumulation ○​ Delays ovulation, increasing pregnancy spacing. ○​ Reduces risk of ovarian and premenopausal breast cancer. Nutritional Needs for Lactating Women: ​ ⇒ Approx 85 kcal are required to produce 100 mL of breast milk ​ ⇒ Prenatal vitamins are often recommended for lactating women to ensure adequate intake Nutrient Recommendation Calories +400–500 kcal/day Protein 71 g/day Calcium No extra intake needed Iron During lactation: 9 mg/day When menstruation resumes: 18 mg/day Fluids 128 oz/day (16 cups) Hypertensive Disorders in Pregnancy ⇒ Hypertension can have severe consequences for mother and baby. HTN Description Chronic Hypertension ●​ Pre-Existing high blood pressure before pregnancy ●​ Or within the first 20 weeks ●​ Does not resolve by 12 week postpartum check up Gestational Hypertension ●​ Onset of HTN after 20 weeks ●​ Can develop into preeclampsia. ●​ DX Requires: ○​ Elevated blood pressure (systolic ≥ 140 or diastolic ≥ 90 mm Hg, the latter measured using the fifth Korotkoff sound) ○​ Previously normal blood pressures ○​ No protein in the urine ○​ No manifestations of preeclampsia/eclampsia. Preeclampsia ●​ Defined in a woman who had normal blood pressure prior to 20 weeks and has no proteinuria ●​ High BP (≥ 140 mm Hg systolic or ≥ 90 mm Hg diastolic) ) + proteinuria after 20 weeks. ○​ Two elevated blood pressure measurements 6 hours apart and a proteinuria of 300 mg in a 24‑hour urine specimen. Eclampsia ●​ Development of seizures in a preexisting pre‑eclampsia ●​ May appear unexpectedly in a patient with minimally elevated blood pressure and no proteinuria. ●​ Exact cause is unknown but cerebral ischaemia and edema are ●​ suggested. ●​ The timing of an eclamptic seizure can be antepartum (53 percent), intrapartum (19 percent), or postpartum (28 percent) ●​ Overall occurrence is rare Postpartum Preeclampsia ●​ ●​ ●​ ●​ High blood pressure and excess protein in your urine soon after childbirth Can occur up to six weeks post-delivery. Most cases of postpartum preeclampsia develop within 48 hours of childbirth. Untreated cases may lead to seizures and maternal mortality.