Nutrition in Pregnancy and Infancy

Chapter 17: Life Cycle Nutrition: Pregnancy through Infancy

• Preconception Period: Lifestyle choices before conception affect the baby's health at birth and beyond.

• Prenatal Development: A pregnant person's diet must support the health of the pregnant person and the growing baby. Full-term pregnancies last 39-40 weeks and are divided into three 13-week trimesters. Prenatal development is divided into embryonic and fetal periods. The embryonic stage is from week 3 to week 8 after conception and the fetal stage is from week 9 onward.

• Placenta: The placenta allows the exchange of nutrients, oxygen, and waste products between the mother and fetus through the umbilical cord. It prevents the passage of red blood cells, bacteria, and large proteins from mother to fetus. It also releases hormones to support physiological changes of pregnancy. Maternal and fetal blood do not mix but the placenta allows the embryo to use the mother's organ systems.

• Learning Outcomes: The learning objectives of this chapter as outlined by the book cover topics ranging from the specifics of the stages of pregnancy and importance of the placenta, to dietary and lifestyle factors in a successful pregnancy, further to dietary needs and complications during pregnancy through infancy, including descriptions of breastfeeding benefits along with infant formula as a healthy alternative.

• Factors for Prospective Fathers: Lifestyle and dietary habits of the father can affect fertility and sperm production. These factors include smoking, alcohol/drug abuse, and obesity.

• Factors for Prospective Mothers (Pre-Pregnancy): Health professionals recommend that pregnant women attain a healthy weight prior to conception. Obesity and overweight could lead to fertility issues or complications during or after pregnancy. This includes an increased risk for gestational diabetes and hypertension, labor/C-sections, and birth defects. Underweight women may be at risk of delivering premature, low birth weight babies that may have developmental issues.

• Factors for Prospective Mothers (During Pregnancy): Consume adequate folic acid (400-600 mcg) prior to and during pregnancy to reduce neural tube defects. Consume safe fish (2-3 servings a week) to avoid methylmercury that can harm the developing nervous system. Consume moderate amounts of caffeine (under 200 mg per day). Avoid cigarettes, alcohol, and illicit drugs. Avoid dietary supplements (herbal remedies) since there may not be enough research to assess their safety. Manage chronic conditions like diabetes, hypertension and PKU since they affect pregnancy outcome.

• First Trimester: Changes occur in the mother's body and fetus. The liver forms red blood cells, the heart begins to beat, limbs take shape, and the brain grows rapidly during this period.

• Weight Gain during Pregnancy: The fetus makes up about one-third of the total weight gained during pregnancy; the remainder is composed of maternal tissues and fluids such as blood, uterus, and breasts. A woman at a healthy weight (BMI 18.5-24.9) is recommended to gain between 25-35 pounds during pregnancy in total, with a recommended gain of 1-4.5 pounds in the first trimester.

• Nutrient Intake: Increased needs for certain vitamins and minerals are present in pregnant women in the second and third trimesters of pregnancy. Folates, iron, calcium, zinc, copper, and vitamin D are amongst the prominent nutrients required during pregnancy.

• Morning Sickness: Morning sickness can occur at any time of the day and can be triggered by scents. To combat the symptoms, small, frequent meals with carbohydrates are recommended.

• Food Safety: Pregnant women should avoid consuming raw or undercooked meat, unpasteurized milk/cheese/juice, and raw sprouts. Excess vitamin A can be toxic in pregnancy. Sugar substitutes are okay in moderation with a balanced diet.

• Nutritional Needs of Infants: Infants grow at an accelerated pace, increasing in weight by doubling their initial weight by 6-months and tripling it by 12-months. Adequate nutrition is crucial for infants' physical, social, and intellectual development. Specific requirements for daily kilocalories and nutrients, like carbohydrates (60-95 grams), proteins (9-11 grams), and fat (as needed) exist for the first 6 months and 7-12 months. Vitamin D, iron, and vitamin K are also needed.

• Introduction of Solid Foods: The introduction of solid foods for infants is done gradually, usually when they reach 4-6 months of age. The parents should watch for any signs of food allergies. Different foods should be introduced individually over a time.

• Food Allergies: A food allergy is an abnormal reaction of the immune system to a specific food; and those who have food allergies can suffer severe reactions. Food allergens are typically proteins. Food allergies and allergic reactions may manifest through several issues, such as difficulty in breathing, and physical symptoms in the form of rashes, vomiting, and diarrhea.

• Breastfeeding: Lactation is the production of milk in a woman's body. The infant suckling at the mother's breast stimulates milk production (Prolactin), and milk production can be released through "letdown" response (Oxytocin). Breast milk changes in composition as the infant grows, from colostrum (rich in protein and immune factors) to later breast milk (higher in lactose, fat, and B vitamins). It provides nutritional and health benefits to the infant such as decreasing risk of infections, allergies, and chronic disease. Mothers are also said to benefit from breastfeeding, including a reduction in blood loss during pregnancy, and returning to their pre-pregnancy weight or maintenance of weight, reduced risks of ovarian/breast cancer, and risk for hip fractures, along with helping increase bone density and lowering risks for type 2 diabetes.

• Formula Feeding: Formula can be a healthy alternative to breastfeeding, and is developed to be similar to breast milk, made from cow's milk (altered). Women who are unable to breastfeed include those with HIV/AIDS, tuberculosis, those undergoing chemotherapy or radiation, and those taking medications. Galactosemia is another condition where women should not breastfeed.

• Gestational Diabetes, Macrosomia, etc. Gestational diabetes occurs with high blood glucose levels after 20 weeks of pregnancy, causing a larger than usual baby (macrosomia). This may increase risks for jaundice, breathing problems, birth defects, and hypoglycemia after birth. Overweight or obesity is associated with gestational diabetes, as are older ages and certain ethnicities.

• Hypertension: Pregnancy-induced hypertension can be a serious complication, including three categories namely: gestational hypertension, preeclampsia, and eclampsia. Gestational hypertension arises during pregnancy, preeclampsia occurs with hypertension and edema, and protein losses in the urine which deprives the fetus from oxygen. Eclampsia can lead to seizures. Bedrest, medications, and hospitalization can help treat preeclampsia.

• Jaundice: Jaundice is a condition that causes skin, eyes, and mucous membranes to turn yellow due to excess bilirubin, a yellowish pigment of bile. It can be a sign of some pregnancy complications.

• Other Considerations: Lifestyle habits such as habits on alcohol, drugs, tobacco, and caffeine consumption for breastfeeding. Dietary habits as they relate to possible restrictions (like with fish consumption) must be considered.

This quiz covers essential topics related to life cycle nutrition, focusing on the preconception period, prenatal development, and the role of the placenta. Understand how maternal lifestyle choices and nutrition impact fetal health and development during pregnancy. Test your knowledge on key concepts that are crucial for a healthy pregnancy and infancy.