R8 - Fetal and Placenta

Question 1

Cytotrophoblast

Answer 1

– Mononuclear
– Regenerative
– Structural, adhesive and invasive
* Chorionic villi, basal plate, extravillous, invasive, amnion

Question 2

Syncytiotrophoblast

Answer 2

– Multinuclearcellmass
– Endocrine, metabolic function
– Lines lacunar blood spaces
– Exchange barrier of placenta

Question 3

Transport barrier

Answer 3

1. Microvillous membrane
2. Syncytiotrophoblast cell
3. Basal membrane
4. Villous mesenchyme
5. Fetal capillary endothelium

Question 4

Placental Functions

Answer 4

• Gas exchange
• Nutrient delivery
• Waste removal
• Endocrine organ
• Immunologic barrier
• Controls parturition

-beauty products

Question 5

Villous Maturation

Answer 5

Facilitates transport
-terminal villi expansion, syncytial knots
-villous compaction, capillary expansion
-cytotrophoblast attrition

Question 6

The _____ fetal PaO2 is equivalent to uterine venous effluent

Answer 6

highest

Question 7

Fetal Oxygen Transport Adaptations

Answer 7

-High flow, low resistance
-Fetal polycythemia
-Fetal hemoglobin: greater O2 affinity
-Fetal Bohr: increase pH in cap, decrease CO2

Question 8

Fetal Hemoglobin

Answer 8

– α2γ2
– ↑ O2 affinity
– ↑ O2 content
– ↑ O2 saturation

Question 9

Fetal gas exchange falters if…

Answer 9

-Maternal hypotension <70
-Maternal oxygen desaturation <94
-Excessive uterine contractions
-Failed endovascular invasion

Question 10

Fetal Circulation

Answer 10

-PARALLEL circuit
-High pulmonary vascular resistance
-Intra- and extracardiac shunts
-Low systemic vascular resistance

Question 11

H-P-A Axis in the Fetus

Answer 11

-Developed at 6-12 weeks
-Pituitary: all adult hormones present, typical feedback control, receptive to CRH placental
-Adrenal: 30x larger than adult

Question 12

Energy requirements

Answer 12

87 kcal/kg/day

Question 13

Determinants of Fetal Growth

Answer 13

-Physio: gender, race, parity, altitude, maternal birth weight

-Patho: genetics, infection, malnutrition, vascular disease, toxins, multiple gestation

Question 14

Fetus regulates own growth
– Independent ofmaternal hormones, but…

Answer 14

• Dependent on substrate delivery
  – Most powerful determinant
  – Activates fetal growth control mechanisms

Question 15

Intrauterine Growth Restriction

Answer 15

2nd leading cause of perinatal mortality

Detection
– Poor maternal weight gain
– Lagging fundal height
– Ultrasound estimated weight
– Birth weight
– Ponderal index

Question 16

Causes of IUGR

Answer 16

SYM: genetic, infections, toxins

ASYM: placental, maternal, environmental

Question 17

Fetal Overgrowth

Answer 17

Maternal diabetes
-hyperglycemia, hyperinsulinemia
-birth injury, C section, childhood obesity