Unit 1 Flashcards
Preconception, Pregnancy and Lactation
Preconception nutrition
The time before conception (before pregnancy)
Preconception
The period (at least 2 years) before and between pregnancies, to improve health related outcomes for women (regardless of their pregnancy status), newborns and children upto 5 years
Preconception Proximal period
Period preceding pregnancy (up to 2 years prior to conception)
Preconception Distal period
Adolescents or in general a longer time before pregnancy
Periconception
The period preceding including and immediately following human conception, to improve health related outcomes for women, newborns and children up to 5 years
Preconception boundary
3 months before pregnancy to up to the first trimester
Critical window
First 1000 days (2 years)
key to brain development, healthy growth and a strong immune system
The periconception period
3 months prior to conception
*biologically 5-6 months
Why does excess body fat decrease fertility?
- higher estrogen, leptin, androgen (males and females and lower testosterone in males)
- menstrual cycle irregularity (30-47%)
- reduced sperm production and erectyle disfunction
Why does inadequate body fat decrease fertility?
- Weight loss exceeding 10-15% decreases estrogen, LH and FSH = amenorrhea, anovulatory cycles, short/absent luteal phases
- Critical level of body fat (BMI>20kg/m2) REQUIRED to trigger and sustain normal reproductive functions
- Low levels of body fat during adolescence delays onset of menstruation and reduces fertility
- LT consequences of undernutrition revealed during famine (Dutch famine 194/5)
What does Periconceptional nutritional status influence?
offspring, metabolism, organ growth, development and function, leading to increased risk of chronic disease
Choline
Brain development
Iron
Iron deficiency anemia linked with LBW, delayed development, preterm birth, infections, postpartum hemorrhages
Iodine
- Thyroid and metabolism
- Neural growth and development of fetus (Neurocognitive)
- Iodine deficiency: adversely affect neurological and psychological development and can cause intellectual disability (SEVERE)
- RDI: 160mcg/ day
- RDA: 220mcg/d
- *In NZ pregnant women are at risk of mild iodine deficiency so supplement is needed (along with use of iodised salt)
Zinc
Preterm birth, placenta function
Omega-3 fatty acids and B12
altered lipid metabolism
Multivitamins
- Neural tube defects
- Congenital heart defects
- Urinary tract defect
- Limb reduction defect
- preeclampsia
Folic Acid
- Neural tube defects
- Congenital malformations
- Preeclamsia (BP, fluid retiontion)
- autism
- increased sperm count and viability
- 800mcg/day (4w before pregnancy and 12w after)
- contains gluten
Periconceptional folic acid
Prevents(1st and second) /reduces neural tube defects (spine and brain)
1st trimester
Conception to 12th week
Estimated date of delivery (EDD)
counted from 1st day of LMP (40 weeks from here/38 weeks after conception)
2nd trimester
Week 13-28
3rd trimester
Week 28 to birth
Pre-term (premature)
<37 weeks
Term
37-43 weeks
Post-term (postmature)
> 42 weeks
Placenta
- Temporary organ grown during pregnancy and feeds the baby and
carries O2, antibodies and nutrients (also removing waste from fetus to mother e.g. CO2) - Starts implantation of the blastocytes
- Placenta (trophoblast) are outer cells of the fetus (embryoblast)
- Fully formed by 18-20 weeks
- Takes over hormonal role of ovary
- Connected to the fetus(embryo) by umbilical cord
Human Chorionic gonadotropin (HCG)
- pregnancy hormone (recognizes if pregnancy is viable)
- Prevents release of more eggs for fertalisation
- Combination of controlling other hormone in body (increased estrogen etc)
- peaks at early stages of pregnancy and maintains pregnancy
Umbilical arteries
carry deoxygenated blood from fetal circulation to placenta
Umbilical veins
carry newly oxygenated blood and nutrient rich blood to fetus
Teratogens
- Distubing development of an embryo or fetus.
Can cause birth defects in the child or - halt pregnancy
e.g. Radiation, maternal infections, chemicals, drugs
Physiological changes during pregnancy
- Weight gain: 12-15kg
- Hormonal: increase
- Metabolic and renal: increase in fluid
- Cardiovascular: increase in HR & BP
- Respiratory: difficulty breathing due to pressure on lungs
- Hematological: Increase in plasma volume and decrease in hemoglobin (RBC), iron deficiency
- Gastrointestinal: Decreased GI motility from elevated progesterone relaxing smooth muscle and pressure on colon and rectum causing constipation (also due to iron supplements).
Hormonal changes during pregnancy
- Continually Increased progesterone and estrogen (via placenta), suppressing hypothalamic axis thus menstrual cycle and promoting prolactin = milk hormone
- Increased parathyroid hormone for calcium uptake (gut) and reabsorption (kidney)
- Increased cortisol and aldosterone (adrenal)
- Placenta produces HLP (only present when pregnant)
Human Placental Lactogen (HPL)
Hormone produced by plancenta when pregnant.
- Decreases insulin sensitivity and glucose utilizations = raises blood glucose level for adequate fetal nutrition.
- Increases gluconeogenesis to increase glucose for availability for fetus
- Chronic hypoglycemia leads to rise in HPL.
- HPL includes lipolysis, release of FFA to fuel mother. Ketones formed by FFA can be used for fetus as well as glucose.
*these functions help to support fetal nutrition even in the case of malnutrition
Hematological changes in pregnancy
- Increase in BV proportionally to CO (40/5%)
- BV increases in early pregnancy (faster than RBC) :. *More plasma volume than RBC in early pregnancy
- increased plasma volume DECREASES RBC (dilutional anemia)
GI changes in pregnancy
Constipation:
- enlarged uterus puts pressure on rectum and lower colon
- Decreased gi motility from increase in progesterone relaxing smooth muscle
- Iron supplements
- Heart burn and belching from delayed gastric emptying
- Gastroesphegal reflux due to lower esophegeal spincter relaxing
Lower HCI :. Ulcer uncommon
Hyperemesis gravidarum (HP)
Extreme form of NVP / Sever morning sickness
- weight loss, electrolyte imbalance and dehydration requiring hospitalisation.
- Poor outcomes
- Impacts neuro development and increased risk in respiratory and cardiac disorders
- Hormone growth differentiation factor 15 (GDF15) and NVP link
- Sensitivity to GDF15 influences severity
- Higher maternal levels = increased vomiting
Pregnancy outcomes with NVP or NP
Pelvic girdle pain (126% greater odds) high blood pressure (40% greater odds), proteinuria (50% greater odds), preeclampsia (13% greater odds),
18% more likely to be a girl baby
Delivery/birth outcomes with NVP or NP
Gestational length, c-section delivery, mortality, growth of infant
WITH NVP or NP = More likely to develop pregnancy complications but do exhibit mostly favorable delivery and birth outcomes
true
NVP mangement
- reduce sympotoms via diet/environment
- correct/prevent consequenses or complications of NVP
- minimise fetal effects of maternal NVP and their treatments
Assisted reproductive techniques (ART)
Scientific methods for fertility
e.g. In vitro fertilization-embryo transfer (IVF-ET), Gamete intrafallopian transfer (GIFT), zygote intrafallopian transfer (ZIFT), Frozen Embryo transfer (FET)
ART eligibility criteria
- <35 BMI and drop to <32, <40y/o (F) and <55y/o (M)
- unsuccessful with pregnancy after 12 months of intercourse
- non-smoker for 3 months
- can not have 2+ children
- nz citizen
Single/lesbian/gay: Anovulation or very irregular periods (<20 or <42 days), Known tubal infertility, Severe endometriosis
common health problems that women experience during early pregnancy
· Nausea and vomiting
· Heartburn
· Fatigue
· Constipation/Hemorrhoids
Food aversions
Ginger
- improve symptoms of nausea and is more effective than vitamin B6.
- Dose and frequency: ~ 1 g/d (550 – 1050 mg per day) divide twice to 4 times per day (to manage symptoms) via food or beverages Ginger can have positive effects in early pregnancy - NOT be taken in third trimester or close to labour (contra-indication).
· Communicate that some ginger supplements contain agents with questionable safety in pregnancy.
- Dose and frequency: ~ 1 g/d (550 – 1050 mg per day) divide twice to 4 times per day (to manage symptoms) via food or beverages Ginger can have positive effects in early pregnancy - NOT be taken in third trimester or close to labour (contra-indication).
What is vitamin D required for?
calcium absorption/uptake important during pregnancy or could specify support fetal bone health
What is the recomended does of vitamin D for pregnant women?
5 mcg/d
important nutrients for pregnant women
Iron: + 1 g of for pregnancy (specifically for the fetus and placenta, during delivery, and to increase red blood cell mass
Vitamin C: iron absorbtion
Folate: 800 mg (neural tubal)
Vitamin B6: fortified cereal
Vitamin B12: dairy
Zinc: deficiency can increase risk of fetal loss, congenital malformations, low birth weight
Iodine: (brain development) 150mg
listeriosis
a food-borne infection that results from eating food contaminated with Listeria a common bacterium that can be harmful to the fetus
- sealed packs; eat cold or cooked within two days of opening pack
- reheat leftovers to piping hot >70degrees
- fresh/washed vegetables vs deli)
· was the rocket washed
*for pregnant, hummus and sprouts is advised not to eat – sesame seeds raw, including in tahini, are a risk) and avoid fresh juice that is unpasteurised
food safety concerns
Listeriosis and Toxoplasmosis
Recommendations for total and rate of weight gain during pregnancy
12-15kg and 0.42kg per week in trimester 2&3
*higher for twins (17-25kg)
Components of gestational weight gain (GWG)
- Water (62%)
- Fat Mass (30%)
- Fat-free mass (8%)
1/4 from fetus as 90% fetal growth occurs later in pregnancy
Rate of gestational weigth gain (GWG)
1st trimester: low
2nd trimester: reflects deposition and expansions of maternal tissue (1/3)
3rd trimester: fetal, placental and accumulation of amniotic fluid (2/3)
Overweight & obese are more likely to overestimate weight gain than normal weight women (T or F)?
True
Healthy weight gain advice
-30 mins moderate intensity PA 5 or more times a week
- Healthy eating
- Awareness of weight gain guidelines
Monitor weight - target weight gains are strongly associated with actual gains
What % of pregnant women don’t have healthy weight gain?
75%
under (23%)
over (50%)