Overview
This lecture introduces Unit 5, beginning with pregnancy, breastfeeding, and infancy. It covers the importance of nutrition before and during pregnancy, factors affecting pregnancy outcomes, trimesters, and physiological changes in mothers.
Introduction to the Unit
- Unit 5 focuses on nutrition during pregnancy, breastfeeding, infancy, toddlerhood, adolescence, and older adulthood.
- Chapter 17 discusses pregnancy, with later chapters addressing other life stages.
Importance of Nutrition Before and During Pregnancy
- Maternal nutrition and lifestyle significantly impact the immediate and long-term health of the child.
- Male factors also affect pregnancy, including diet, weight, alcohol, and antioxidant intake for sperm health.
Infant Birth Weight and Health Outcomes
- Infant birth weight is a strong predictor of future health; ideal range is 7-8 lbs.
- Low birth weight (under 5.5 lbs) increases risk of infant mortality, chronic disease, and future obesity.
- High birth weight (over 10 lbs) can complicate delivery and increase risk of chronic diseases for the child.
Pregnancy Terminology and Stages
- Full-term pregnancy: 39-40 weeks; pre-term: under 37 weeks.
- First trimester (first 12 weeks) is critical for organ development; embryo called zygote, later embryo, then fetus.
Factors Affecting Pregnancy Outcomes
- Planning is ideal but up to 75% of US pregnancies are unplanned.
- Age: Under 18 or over 35 increases risks during pregnancy.
- Mom’s weight: Underweight increases risk of low birth weight; overweight increases risk of large babies and complications.
- Chronic health conditions and closely spaced births can negatively impact pregnancy.
- Lack of prenatal care triples the risk of low birth weight.
- WIC program provides food and education to support maternal and child health.
- Stress, sleep, physical activity, and diet also play roles in pregnancy outcomes.
Trimesters and Critical Periods
- First trimester is essential for organ and system development; deficiencies or toxicities can cause lasting issues.
- Malnutrition during early pregnancy linked to future heart disease and obesity in offspring.
- Later trimesters focus on growth but nutrition remains important.
Changes in the Mother During Pregnancy
- Pregnancy increases body water by 50% and blood volume; kidney function changes to conserve water.
- Fat stores and placental development support fetal growth and later lactation.
- Hormonal changes affect metabolism, cholesterol, appetite, and GI function (constipation, nausea, reflux).
The Placenta
- The placenta is the organ for nutrient and waste exchange between mother and fetus without blood mixing.
- Most large molecules cannot cross the placental barrier, but substances like alcohol and some medicines can.
- Placenta is delivered after the baby and a new one forms with each pregnancy.
Key Terms & Definitions
- Low Birth Weight — birth weight under 5.5 lbs, linked to higher health risks.
- Full-term Pregnancy — pregnancy lasting 39-40 weeks.
- Placenta — organ that exchanges nutrients and waste between mother and fetus.
- Trimester — each of three roughly 12-week segments of pregnancy.
- WIC — Women, Infants, and Children; a government program providing food and nutrition education.
Action Items / Next Steps
- Review textbook sections on factors affecting pregnancy and WIC.
- Prepare for next lecture on specific nutritional requirements for pregnancy.