Pregnancy Flashcards
… and … are considered to be among the most important environmental factors influencing the course and outcome of pregnancy?
Maternal diet and nutritional status
How long is gestation and trimesters?
Gestation 40 weeks Divided into trimesters First trimester: 0-12 weeks Second trimester: 13-27 weeks Third trimester: 28-40 weeks
What happens at 0-2 weeks of fetal development?
fertilisation to embryonic disc, less sensitive to teratogenesis ( process by which congenital (disease from birth) malformations are produced) and high rate of lethality (death of embryo).
What happens to a foetus at 3-8 weeks?
Turns from embryo into fetus, most sensitive to teratogenesis, major organs form each of which have a peak sensitivity period.
What happens to a fetus from week 9 to 38?
Turns from fetus to baby, decreasing sensitivity to teratogenesis, period of growth and functional maturation.
Physiological changes during pregnancy?
Maternal weight gain and body composition changes
Blood volume expansion and cardiovascular changes
Renal changes
Respiratory changes
Gastrointestinal changes
Metabolic adaptations
Components of maternal weight gain during pregnancy?
Foetus (only a third of the weight gain, placenta and amniotic fluid
Mammary glands, uterus
Lean body mass, fat
Plasma volume, extracellular body water
Optimal maternal weight gain?
Underweight (< 18.5kg/m2) = 12.5 – 18kg Healthy (18.5 – 24.9kg/m2) = 11.5 – 16kg Overweight (25 – 29.9kg/m2) = 7 – 11.5kg Obese (>30kg/m2) = 6.8kg minimum No one should loose weight
Gastrointestinal Changes?
Adaptations to increase gut absorptive capacity influenced by progesterone and oestrogen
Increased availability to maternal and foetal structures and stores
Reduction in secretion of gastric juices
Gastric emptying slowed (food churned in stomach longer)
Motility of small and large intestine reduced (so food exposed to more enzymes)
The nutrient requirements during pregnancy must provide adequate nutrients to meet…?
The needs of the mother
The needs of the foetus
To some extent, then needs of mother and foetus in the future (lactation)
Maintenance of a normal pregnancy requires energy due to…?
increased mass of the uterus formation of the foetus formation of the placenta the expanded blood volume extra adipose tissue to provide energy reserve for lactation
Energy requirements may increase but what factors might slightly mitigate this effect/ cause issues?
BMR may decrease due to endocrine changes in pregnant women
Physical activity may decrease in the pregnant woman
Food intake may decrease in the pregnant woman
When does energy intake increase in pregnancy?
Last few weeks, average increase under 100 extra calories a day.
What are the recommendations for energy intake in the third trimester? Exceptions
Increase EAR by 200kcals/day above pre-pregnant EAR (only during last trimester)
Large increase in food intake NOT required
Maternal obesity associated with increased risk of congenital malformations
Exceptions:
women underweight at beginning of pregnancy, and women who do not reduce activity may need more
What is a better indicator than the recommendations of energy sufficiency?
Appropriate weight gain and appetite are better indicators of energy sufficiency that the amount of kcal consumed
Protein Requirements
Protein required for growth of the foetus and maternal tissue
Overall gain of almost 1kg protein during pregnancy
most during 1st to 2nd trimester
Increased protein turnover during pregnancy
Excess protein associated with health risks
DRV additional 6g /day (RNI 51g/day)
Current UK intakes in excess of RNI
After 20 weeks foetal liver can synthesise non-essential amino acids from precursors
Importance of lipids in pregnancy?
Crucial for foetal development
membranes and brain
Uptake depends on dietary supply
Effects
Depletion of DHA associated with reduced visual function and learning defects in children, supplementation from 2nd trimester may improved visual aspects and tests on intelligence and achievement in infants.
High intakes of n-3 fatty acids proposed to extend gestation, increase birth weight and reduce risk of premature delivery. Caution with increased intake from potential contamination of fish oils with mercury and other potentially teratogenic agents. Fish oil supplementation may increase maternal bleeding and risk of postpartum haemorrhage.
Importance of vitamin A and food recomendations?
Vitamin A
Required for growth and maintenance of foetus
Maternal requirements increased by 100µg throughout pregnancy but most UK women already consume sufficient
> 8000 µg/d increased risk birth defect
Advise
no liver/ liver products
No Vitamin A supplements
Vitamin C recommendation in third trimester?
Increase mothers RNI by 10mg/d
Vitamin D recommendations?
Vitamin D deficiency can be passed on to the baby during pregnancy
Requirement 10µg/d supplementary Vitamin D
If mother supplements with vitamins what should she take?
Avoid use of single vitamin supplementations
If supplementation necessary, use pregnancy suitable multi-vitamins (exclude vit. A)
Zinc requirements?
During pregnancy there is a requirement for extra zinc, but studies have found no benefit to providing zinc supplements. It is likely that there is some metabolic adaptation to provide sufficient zinc so no additional requirements.
Magnesium requirements?
adaptive response and release from maternal stores overcome additional requirements
Iron recommendations and issue?
cessation of menstruation, mobilisation of maternal stores and increased intestinal absorption overcome additional requirements
if supplements required, can contribute to constipation
Common aversions in pregnancy?
Early pregnancy - commonly tea, coffee, alcohol, fried food, eggs
Later pregnancy - sweet foods
What are pregnancy cravings and should they be a reason for concern?
compulsive urge for food not previously desired in excess
Random foods, varying within individuals
Rarely adversely affects overall nutritional intake
What is Pica and what are the potential causes?
Desire for substances not fit for food
Higher prevalence in rural areas or those with childhood or family history of Pica
Not limited to geography, race, sex, culture, social status or pregnancy
Causes:
? Relieves nausea and vomiting
? Craving produced by nutrient or mineral deficiency
What are some common things to desire eating due to pica?
Dirt or clay (geophagia) - most common Starch e.g. laundry starch (amylophagia) Ice Paper Burnt matches, cigarette ashes, Stones or gravel Charcoal Antacid tablets, milk of magnesia Baking soda, coffee grounds
What are some potential consequences of pica?
Toxicity Malnutrition Obesity Interference with absorption of mineral Intestinal obstruction
Nausea and vomiting in pregnancy (NVP) effects most women in the first trimester, what are the recommendations for this?
Eat crackers, melba toast (dry thinly sliced crispy bread) or dry cereal before getting out of bed
Small frequent meals
Keep hydrated, but separate liquids from solids
Avoid tea or coffee
Avoid or limit fatty and spicy foods
Experiment with food temperatures, flavours and textures
What can be taken to reduce nausea and vomiting in pregnancy, but don’t neceserally recomend?
Ginger has been found to improve mild to moderate nausea and vomiting across several studies and meta-analyses.
Additionally, ginger helps stimulate GI tract motility and increase bile and gastric acid secretion.
vitamin B6 (pyridoxine) taken at doses of 10–25 mg every 8 hours reduces symptoms among women with NVP (would be prescribed)
What is Hyperemesis gravidarum? Complications? Management?
Persistent vomiting occurring before the 20th week of gestation
the occurrence of >3 episodes of vomiting per day with associated ketonuria (using fats and proteins as energy) and weight loss of >3 kg or 5% of body weight.
Complications
Benign
Dehydration, acidosis, alkalosis, ketonuria, poor micro and macro-nutrient provision for mother and child
Life Threatening
Management – fluid and electrolyte replacement, anti-emetics, nutrition support
What is pre-eclampsia? Risk factors? Potential prevention?
Characterised by:
hypertension, proteinuria and oedema
Risk factors
< 20 or > 40 years of age, primiparity, BMI, family Hx
Eclampsia includes grand-mal seizures or coma
May be fatal
Prevention
? Magnesium sulphate, ? Calcium, ? Oxidative stress therefore use of antioxidants
Could antioxidant supplementation prevent pre-eclampsia?
Heartburn?
Increased abdominal pressure caused by enlarged uterus pushing up against the stomach and intestines
Progesterone decreases integrity of cardiac sphincter allowing reflux of food and acid
Exacerbated by spicy, fatty, fizzy or acidic foods, and often by lying down
Commonly occurs in third trimester
Recommendations for heartburn?
Small, frequent meals or snacks
Eat slowly
Milk and yoghurt, or antacids
Avoid lying down for 1 - 2 hours after meals
Gestational Diabetes Mellitus? Associations? Treatment?
Pregnant women with no prior history of diabetes Mostly resolves after birth Associated with: Increased incidence of prematurity Peri-natal mortality Treatment: Low sugar, high fibre diet, regular meals Occasionally require insulin injections
Alcohols potential effect on pregnancy?
Placenta protective, but fat-soluble toxins and teratogens, e.g. alcohol, able to cross
Alcohol during pregnancy may result in
spontaneous abortion, central nervous system impairment, birth defects, foetal alcohol syndrome
attachment disorders (children), difficulties in social situations (adolescents), increased trouble with the law, inappropriate sexual behaviour, depression, failure to care for children and suicide (adulthood)
What are pregnant women with a BMI over 30 more at risk of?
Higher gestational diabetes mellitus (GDM) and pregnancy-induced hypertension (PIH) rate
Higher chronic hypertension rate
Higher cesarean section rate
Higher preterm birth and PROM rate
Higher meconium-stained amniotic fluid rate
Higher LGA infant rate
More frequent low APGAR scores at 1 and 5 min
Higher perinatal death rate, hypoglycemia and the newborn ICU requirement
Higher infection rate
What are pregnant women who are under BMI of 18.5 at risk of?
Higher placental abruption rate Higher vaginal delivery rate Higher SGA (small gestational age) infant rate
Between what weeks in pregnancy do all major organs start to develop?
Between week 3 to 5.
What changes about a pregnant women’s blood?
During pregnancy cardiovascular system needs to adapt to supply large organs and maintain blood suplly to placenta ensuring foetal nutrient supply so overall blood volume increases. When this hsappens compostition of blood changes, mainly plasma increases reducing proportion of proteins notably albumin (involved in plasma pressure and transport in blood). To meet increased demands of oxygen support haemoglobin increases but is still lower than before, so harder to diagnos anemia.
Renal changes in a pregnant women?
Need to pee more often but volume has not increased this is in response to blood and cardiovascular changes (increased plasma)
Respiratory changes in pregnant women?
Diaphragm has a greater range of motion, ribs flair outwards at the bottom so greater amount of air inhaled and expelled. Later on foetus growth starts to get in the way but efficiency is maintained.
Insulin issues in pregnancy and how are the overcome?
Hormones in pregnancy cause some insulin resistance but in 2nd 3rd trimester insulin is 2.-2.5 times higher, some do still develop gestational diabetes though.
What is the factorial method of generating requirements for pregnant women?
Non-pregnant Requirement + increased requirements (increased body mass) - decreased requirements (decreased physical activity, nutrient losses, increased absorbtion)
Requirements for calcium?
mobilisation of calcium stores and increased calcium absorption suggest no additional Ca required
Adolescent pregnancy - supplements required as both mother and foetus require extra calcium
Requirements for zinc?
adaptive response - no additional requirements
Nutrition support for NVP in order of which they would be tried?
Oral nutrition, nasogastric tube, nasojejunal tube (goes past stomach), parentenal nutrition (needle in arm nutrition).
More permanent options: Percutaneous Endoscopic Gastrostomy (tube straight frm stomach wall) and Percutaneous Endoscopic Gastro Jejunostomy (tube from stomach t jejunum)
Constipation and hemorrhoids causes in pregnancy and recommendations?
Progesterone slows peristaltic action of smooth muscles in bowel
Enlarging uterus displaces internal organs (disrupts movement through the GI tract)
Recommendations:
Increased fluid intake
High fibre diet
Increased physical activity
Risks for gestational diabetes?
Ethnicity, over 40, previous elevated blood glucose, previous gestational diabetes, Family history of diabetes (1st degree relative (parents) with diabetes or sister with GDM), polycystic ovary syndrome, previous perinatal loss (miscarriage), multiple pregnancies, BMI over 30, previous large birth weight baby, Medications (corticosteroids (steriods), antipsychotics)
What is toxoplasmosis, what can it lead to, food items that can cause it?
Toxoplasmosis - parasite infection foetal abnormalities, blindness, mental retardation avoid- raw/ undercooked meat unpasteurised goats milk/ milk products unwashed fruit and vegetables cat faeces
What is listeriosis? major sources? results in?
Listeriosis Food poisoning monocytogen Major sources: raw/ undercooked meat unpasteurised milk/cheese Results in: Brain damage
What puts pregnant women at risk of toxoplasmosis?
Unwashed fruit and veg
