Repro 11 - Pregnancy Part 1 Flashcards
What are the fetal components of the placenta? What do each contain and do?
Cytotrophoblast: Inner layer, contains stem cells, core of chorionic villi. Syncytiotrophoblast: multinucleated outer layer, secretes Beta-hCG, transport of gases, nutrients, wastes. “Synch’s w/ the mom”
What are the maternal components of the placenta? What do each contain and do?
Decidua basalis: base layer of endometrium
Describe the umbilical cord.
Contains 3 vessels and blood flow is reversed from what is expected: 2 umbilical arteries which return deoxygenated blood back to the placenta; they come off from the fetal internal iliac arteries. 1 umbilical vein that brings oxygenated blood from the placenta and drains into the fetal inferior vena cava.
What is Urachus? What is patent urachus?
Urachus: connects fetal bladder to yolk sac. Patent urachus: urachus that did not obliterate, leading to urine discharge from the umbilicus.
What is a vesicourachal diverticulum And how is it formed?
An outpouching of the bladder caused by a urachus that only partially obliterated. If it did not obliterate at all, then it’s called a patent urachus (urine from umbilicus).
What is the Vitelline duct? What happens when it fails to obliterate?
It connects fetal midgut to yolk sac. Failure to obliterate causes fistula to umbilicus, causing Meckel diverticulum.
How long is normal term gestation? What is the average gestation? What is the age of viability?
Term gestation: 37-42 weeks. Average gestation is 40 weeks. Age of viability is 24 weeks.
How do we diagnose pregnancy? How long do we have to wait post conception?
Blood in 1 week. Urine in 2 weeks.
What is the G#P#A#?
G=gravidity: number of pregnancies (includes spontaneous miscarriage, elective abortions, fetal deaths). P= parity: number of deliveries above week 20. A= abortions: number of deliveries below week 20.
What is the difference b/w nulliparous vs nulligravida?
Nulliparous: Never delivered. Nulligravida: Never been pregnant.
What is the difference b/w primiparious vs primigravid?
Primiparous: had one delivery. Primigravid: 1st pregnancy.
What are 4 cardiovascular changes seen in physiologic change during pregnancy?
Cardiac output increases 30-50%. BP decreases in early pregnancy: nadir at 16-20 wks, return to pre-pregnancy levels by term. Plasma volume increase 50%, RBC volume increases 30%. Increased procoagulation factors, leading to hypercoagulable state.
What is the cause of Physiologic anemia of pregnancy?
There is an 50% increase of plasma volume but only 30% in RBC volume. Evolution understood that the biggest risk in delivery is bleeding, so even if that happens, the mother can quickly recover.
What respiratory changes are seen in normal pregnancy and why is it beneficial?
There is an increase in minute ventilation, causing decrease in PACO2 and PaCO2, mild respiratory alkalosis and this causes CO2 transferred more easily from fetus to mother.
Why is there an increase in peripheral resistance to insulin during normal pregnancy?
It is due to human placental lactogen (it shunts nutrient to the fetus), and this worsens thru pregnancy, causing hyperinsulinemia, hyperglycemia, hyperlipidemia.
What happens if mother is Rh (-) while the fetus is Rh (+)?
She can develop anti-Rh antibodies if exposed to fetal blood: In the next pregnancy, the IgG Ab can cross the placenta and attack fetal RBCs if Rh (+), leading to hemolytic anemia.
What is RhoGAM and when is it used?
An Anti-Rh IgG. For Rh(-) negative mothers that have Rh (+) fetus. Always use during 3 trimester (Irriguardless of bleeding), time of miscarriage, and always after delivery.
What is contained in a triple screen Of prenatal testing? In a quad screen?
Triple screen: AFP, hCG, Estriol. The addition of Inhibin A makes it a quad screen.
How would the prenatal triple screen come up in a fetus w/ Trisomy 21?
Decreased AFP. Decreased Estriol. Increased hCG.
How would the prenatal triple screen come up in a fetus w/ Trisomy 18?
All markers going to be decreased: AFP, Estriol, hCG.
What things would cause an increase in AFP in prenatal screening?
Neural tube defects. Abdominal wall defects. Multiple gestations.
What is the most common cause of abnormal serum screen?
Incorrect dating.
What are the five indications for amniocentesis?
Abnormal maternal serum triple/quad screen. High risk for trisomy or other genetic defects (above 35y.o, carrier of AR disease). Evaluation of fetal lung maturity (lecithin;sphingomyelin ration above 2.0). In Rh-sensitized pregnancy to detect fetal blood type or fetal hemolysis. Testing for infection/
When can amniocentesis be performed for genetic evaluation? For fetal lung maturity evaluation?
For genetic evaluation: 15-17 weeks. For fetal lung maturity: 3rd trimester.
