Overview
This lecture covers key concepts related to dietary guidelines, infertility, obesity, reproductive physiology, pregnancy, and related health issues, highlighting statistics, definitions, risks, and physiological processes.
Dietary Guidelines and Nutrition
- Sugar should not exceed 10% of total calories; sodium limit is 2,300 mg for those 14+.
- Cholesterol limits were removed; recommended 8 oz fish/week for EPA/DHA.
- Chronic undernutrition leads to low birth weight; acute undernutrition lowers fertility.
- Folate deficiency increases neural tube defects; excess vitamin A or lead, low iodine, and iron can harm fetal development.
Reproductive Health and Physiology
- Infertility: inability to conceive; subfertility: prolonged time to conceive.
- Miscarriage: pregnancy loss before 20 weeks, caused by fetal defects, infections, or uterine issues.
- Older women (>35) have increased chromosomal issues; >50 increases risk of LBW, preterm birth, infant mortality.
- Sperm production in men declines after 35, can continue into old age; paternal age >40 linked to autism.
Menstrual Cycle and Hormones
- Follicular phase: follicle growth, FSH, LH, estrogen; ovulation at day 14.
- Luteal phase: corpus luteum forms, progesterone increases, PMS may occur.
- Key hormones: GnRH (stimulates FSH/LH), FSH/LH (follicle/ovulation/sperm), estrogen, progesterone.
Factors Affecting Fertility
- Women: recent contraceptive use, anorexia, vegan diets, weight loss (amenorrhea).
- Men: heavy metals, heat, steroids, altered hormone levels.
- Alcohol and high caffeine intake (>300 mg) reduce fertility; caffeine recommendation is ≤300 mg pre-conception, ≤200 mg in pregnancy.
Obesity and Metabolic Health
- 34.9% of US adults are obese; higher rates in Black and Hispanic populations.
- Metabolic syndrome: requires 3 of 5 factors (waist, triglycerides, HDL, BP, glucose).
- Infertility in obese: altered hormone levels, oxidative stress, inflammation, lower sperm count (men), insulin resistance (women).
- Bariatric surgery for BMI ≥40, or ≥35 with comorbidities; types: gastric band, Roux-en-Y, sleeve gastrectomy.
Diabetes and Pregnancy
- Diabetes: fasting glucose ≥126 mg/dL; Type 1 (no insulin), Type 2 (insulin resistance).
- Insulin resistance reduces glucose uptake; linked to PCOS, metabolic syndrome.
- High maternal glucose early in pregnancy increases congenital abnormality risk.
- Hemoglobin A1c: normal 4.5-6%, diabetes 5.7-6.4%.
Special Conditions
- PCOS: cysts on ovaries, hormone disruption, insulin resistance, infertility.
- Celiac disease: autoimmune reaction to gluten, causes malabsorption, related to fertility issues; managed by gluten elimination.
Pregnancy Physiology and Outcomes
- Pregnancy increases water volume (7L to 10L), causes edema.
- Placenta functions: hormone production, nutrient/gas exchange, waste removal.
- Preferred fetal fuel is glucose; cholesterol/triglycerides rise during pregnancy.
- Maternal anabolic (early) and catabolic (late) changes support fetal growth.
Birth and Developmental Terms
- Conception: week 0, begins pregnancy.
- Preterm: <37 weeks; term: 38-42 weeks; post-term: >42 weeks.
- Embryo: conception to 8 weeks; fetus: 8 weeks onward.
- Miscarriage most common by 20 weeks.
- Sequence: maternal plasma volume → nutrient stores → placental weight → uterine blood flow → fetal weight.
US Health Statistics
- US infant mortality rate (2014): 6.17%; Black non-Hispanic highest.
- US life expectancy: 78.7 years, ranked 26th globally.
- 11.7% preterm births, 8.2% low birthweight; preterm birth grade: C by March of Dimes.
Key Terms & Definitions
- Miscarriage — Loss of pregnancy before 20 weeks.
- Infertility — Inability to conceive.
- Follicular Phase — First half of menstrual cycle; follicle develops.
- Luteal Phase — Second half of cycle; corpus luteum forms.
- GnRH — Hormone stimulating FSH and LH release.
- Metabolic Syndrome — Cluster of risk factors (waist, lipids, BP, glucose).
- PCOS — Ovarian cysts causing hormonal imbalance.
- Celiac Disease — Autoimmune response to gluten.
- Hemoglobin A1c — Indicator of average blood glucose.
Action Items / Next Steps
- Review definitions and diagnostic criteria for infertility, metabolic syndrome, diabetes, and pregnancy terms.
- Memorize dietary guidelines and recommendations for nutrients (folate, iron, caffeine, alcohol).
- Prepare for questions on hormonal cycles, pregnancy physiology, and obesity statistics.