Lecture 3b: Pregnancy and Physiological Changes Flashcards
What are the main physiological changes during pregnancy?
- Hormonal
- Haematological (blood)
- Gastrointestinal
What happens to progesterone and oestrogen throughout pregnancy?
Rise continually throughout pregnancy - suppressing the menstrual cycle
What happens to HCG throughout pregnancy?
Huge sudden increase then plateau and decline after about 12-16 weeks then continue as low and stable levels
What do high circulating levels of oestrogen promote?
Prolactin production (pituitary gland enlargement)
What do higher levels of prolactin production mediate?
A change in the structure of the mammary gland from ductal to lobular-alveolar = milk hormone
What do high levels of parathyroid hormone promote?
enhance calcium uptake in the gut and reabsorption by the kidney - to support the second skeleton being development
What are the main increased hormonal changes during pregnancy?
- Progesterone
- Oestrogen
- HCG
- Prolactin
- Parathyroid Hormone
- Cortisol
- Aldosterone
What is HPL?
Human Placental Lactogen
Where is HPL produced?
In the placenta
What is the role of HPL?
- Decreases maternal insulin sensitivity and maternal glucose utilisation
- Increases gluconeogenesis
How does decreasing maternal insulin positively influence the fetus?
Raises maternal blood glucose levels, which helps to ensure adequate fetal nutrition
What is chronic hypoglycemia?
blood sugar levels remain consistently lower than normal over an extended period
What does chronic hypoglycemia lead to?
a rise in HPL, which induces lipolysis with the release of FFA’s - become available for mother as a fuel so more glucose can be utilised by the fetus
How does increasing gluconeogenesis positively influence the fetus?
To increase maternal glucose levels so more glucose is available for the fetus
How much does blood volume change during pregnancy?
Increases 40-45% - proportionally with cardiac output
What happens to blood volume in the first trimester?
Plasma volume increases early in pregnancy, faster than RBC volume = hematocrit falls
What happens to blood volume in the second trimester?
Increase in RBC is synchronised with the plasma volume increase = hematocrit stabilises
What is dilution anemia?
the concentration of red blood cells (RBCs) in the blood is reduced due to an increase in plasma volume proportionally - haemoglobin will be lower
If plasma volume increases, will haemoglobin be lower or higher?
Lower
What is the side effects of dilution anemia?
Susceptible to iron deficiency, reduced ferritin and haemoglobin
What are common GI changes during pregnancy?
Constipation, decreased GI motility, heartburn/belching, HCl production decreases
Why does constipation occur during pregnancy?
Pressure from the enlarging uterus on the rectum and lower portion of the colon
Why does GI motility decrease during pregnancy?
Elevated levels of progesterone relax smooth muscle
Why is heartburn/belching common during pregnancy?
Resulting from delayed gastric emptying and gastroesophageal reflux due to relaxation of the lower esophageal sphincter
What is a positive effect of decreased HCl production?
Ulcers become less severe
What is NVP?
Nausea and vomiting in pregnancy
What is NP?
Nausea in pregnancy only
What is morning sickness?
Definition spans from slight dizziness and dry retching to continuous vomiting - not necessarily in the morning
When does morning sickness commonly occur?
Between 5 and 18 weeks - for some women starts earlier and continues after
How many women report some degree of nausea, with or without vomiting?
50-80%
What is hyperemesis gravidarum (HP)?
Extreme form of NVP accompanied by weight loss, electrolyte imbalance and dehydration requiring hospitalisation
How severe is hyperemesis gravidarum (HP)?
Can be life threatening (10%) and can affect the health of the child
What hormone has found to be linked to NVP?
Growth Differentiation Factor 15 (GDF15)
What is the impact of GDF15 on NVP?
Women with severe NVP or HG often have higher levels of GDF15
What are birth outcomes among women experiencing NVP or NP?
Women with NVP or NP more likely to develop pregnancy complications but do exhibit mostly favorable delivery and birth outcomes
What are the goals of treatment for NVP?
- Reduce symptoms
- Prevent consequences
- Minimise fetal effects
What are examples of pregnancy complications among women experiencing NVP?
- Increased pelvic pain
- Proteinuria
- High BP
- Pre-clampsia
How is NVP managed by diet?
- Eat what appeals
- Eat slowly and small amounts often
- Avoid full/empty stomach
- Frequent small CHO
- Cold, clear, carbonated or sour fluids
Can ginger reduce symptoms of NVP?
Improved general symptoms, reduced severity of nausea but did not reduce vomiting
Can B6 reduce symptoms of NVP?
Unclear about effectiveness
Is ginger safe during pregnancy?
No increased risk, some small studies showed conflicting results so we just need to be careful
When does the risk of ginger during pregnancy increase?
Close to labour or in those with history of miscarriage, vaginal bleeding or clotting disorders - NVP tends to be early on so less of an issue
What does of ginger is safe to prescribe?
1g per day - divided into 3-4 doses per day
What is Maori culture towards placenta?
Traditionally bury the placenta to emphasise the relationship between humans and the earth
What is western culture towards placenta?
Most often incinerated or encapsulated
What is placentophagia?
the practice of consuming the placenta after childbirth
What are the suggested benefits of placentophagia?
- Improved lactation, bonding, iron stores, energy, pain
- Prevent postpartum depression
What are the concerns surrounding placentophagia?
- Safe release of placenta from hospital setting
- Introducing harmful bacteria through processing
What is the bottom line for placentophagia?
Limited/no evidence for benefits, exposes mothers and infants to infectious risks - should be discouraged
