Maternal Changes In Pregnancy Flashcards
What are the 3 elements that make up the human blastocyst?
- Inner cell mass: Forms the foetus
- Trophoblast: Forms part of the placenta
- Blastocoel: Fluid filled cavity
When does the endometrial reach their maximum during Uterine receptivity?
- Endometrial changes reach their maximum about 7 days after ovulation.
- The implantation window occurs 6-10 days after the LH spike
When does pre decidualization occur during Uterine receptivity?
Pre decidualization occurs 9-10 days after ovulation, decidual cells cover surface of the uterus
What happens when Decidualization occurs?
- Decidualization occurs if pregnancy occurs, decidual cells are modified and become filled with lipids and glycogen
- Decidua becomes maternal part of the placenta
What does glandular secretions contain?
- Growth factors
- Adhesion molecules
- Nutrients
- Vitamins
- Matrix proteins
- Hormones
What happens at day 7-8 of implantation?
- Blastocyst attaches itself to the surface of the endometrial wall (Decidua basalis)
- Trophoblast cells start to assemble to form a syncytiotrophoblast in order to facilitate invasion of the Decidua basalis
What happens at day 9-11 of implantation?
- Syncytiotrophoblast further invades the Decidua basalis
- By day 11, it’s almost completely buried in the Decidua
What happens at day 12 of implantation?
- Decidual reaction occurs
- High levels of progesterone result in the enlargement and coating of the decidual cells in glycogen and lipid rich fluid
- This fluid is taken up by the syncytiotrophoblast and helps sustain the blastocyst early on before the placenta is formed
What happens at day 14 of implantation?
- Cells of the Syncytiotrophoblast start to protrude out to form tree like structures known as primary villi
- Which see then formed around the blastocyst
- Decidual cells between the primary villi begin to clear out leaving behind spaces known as Lacunae which fill the maternal blood
How is a pregnancy recognised maternally?
- Human chorionic gonadotrophin (hCG) secreted by the syncytiotrophoblast increases rapidly and is the basis of a pregnancy test
- hCG prevents the death of the corpus Luteum so the endometrium is not shed
- The corpus Luteum continues to produce steroids estrogen and progesterone.
- Rapid change in maternal systems in response to luteal and later placental steroids
Describe the different stages of the hormone concentration against weeks of pregnancy graph
- Estrogen is produced from the start (week 0)
- progesterone starts production at 2nd week
- Serum hCG is produced just before the 4th week
Describe the different stages of the hormone concentration against weeks of pregnancy graph (PART 2)
- Serum hCG concentration peaks the highest at week 10
- Estrogen and Progesterone concentration gradually increases
- After week 10, Serum hCG conc decreases rapidly and falls below Estrogen & Progesterone conc at around week 24
- At week 24 Estrogen conc surpasses progesterone conc
What is the order of finish for the hormone concentration against weeks of pregnancy graph
- Estrogen
- Progesterone
- Serum hCG
Where is progesterone synthesised from?
Where is it needed?
- Synthesised directly from cholesterol
- Decidualization (CL)
- Smooth muscle relaxation: Uterine quiescence
- Mineralcorticoid effect: Cardiovascular changes
- Breast development (glands and stroma)
Where is Estrogen synthesised from?
Where is it needed?
- Synthesised from steroids derived from foetal and maternal adrenals
- Development of uterine hypertrophy
- Metabolic changes (insulin resistance)
- Cardiovascular changes
- Increased clotting factor production
- Breast development (glands and stroma)
What is the average total weight gain for a women during pregnancy?
Around 9-13 kg
What factors causes most of this weight gain?
- Foetus and placenta: 5 kg
- Fat and protein: 4.5 kg
- Body water: 1.5kg
- Breasts: 1 kg
- Uterus: 0.5 kg
What would happen if this weight gain is not reached?
- Failure to gain or sudden change requires investigation
- Constant weight monitoring can cause anxiety
How is weight expected to increase during pregnancy?
- Around 2 kg in total for the first 20 weeks
- Then approximately 0.5 kg per week until full term at 40 weeks
- A total of 9-13 kg during the pregnancy
How much does the basal metabolic rate increase by?
- 350 kcal/day mid gestation
- 250 kcal/day late gestation
- 9 calories = 1g fat therefore 40g fat for 350 kcal
- Glucose increases in the maternal circulation in order to cross the placenta
How does glucose in the body change in the first trimester of maternal reserves?
- Pancreatic cells increase in number raising circulating insulin
- So more glucose is taken up into tissues
- Fasting serum glucose decreases