clinical issues with placenta

Question 1

can drugs/chemicals cross placenta?

Answer 1

nearly all to some degree

Question 2

what does chronic alcohol consumption do to fetus?

Answer 2

increase the risk of fetal alcohol syndrome

Question 3

what can cocaine abuse during pregnancy lead to?

Answer 3

a. fetal/newborn addition

b. preterm labor in 25% in women using cocaine compared to 8% in women without cocaine.

Question 4

what could cause preterm labor in cocaine users?

Answer 4

possibly due to increased constriction of placental blood vessels and/or increased contractility of uterus

Question 5

what happens to abnormal blastocysts?

Answer 5

they occur at a significant frequency and most are probably never realized to exist. others persist.

Question 6

what are gestational trophoblastic tumors (GTTs)?

Answer 6

encompass a number of neoplastic disorders derived from trophoblastic cells. such disorders include partail and complete hydatidiform moles, as well as choriocarcinomas.

Question 7

Are GTTs common? curable?

Answer 7

uncommon and have a high cure rate (90-95% for choriocarcinomas)

Question 8

how often do hydatidiform moles occur?

Answer 8

0.1-0.5% of pregnancies. about 80% of GTTs are non-malignant hydatidiforms.

Question 9

how is molar incidence related to maternal reproductive age?

Answer 9

incidence increases with extremes in maternal reproductive age. incidence is higher in women younger than 20 and older than 40.

Question 10

what other factors increase incidence of hydatidiform moles?

Answer 10

prior molar pregnancies, lower socioeconomic status, and certain ABO blood groups. variations in incidence have also been correlated with geographic regions and cultures.

Question 11

how are cells of a complete hydatidiform mole diploid?

Answer 11

the result of a sperm fertilizing an oocyte with a degenerated female pronucleus (46XX). paternal chromosomes may duplicate resulting in a diploid cell - an extreme example of the phenomenon of parental imprinting.

Question 12

does complete hydatidiform mole have an embryoblast?

Answer 12

no. it is characterized by diffuse trophoblastic hyperplasia and diffuse villous edema

Question 13

describe partial hydatidiform moles?

Answer 13

have partial embryoblast development and are usually triploid with 2 sets of paternal chromosomes of a normal oocyte (69XXY). trophoblastic hyperplasia and villous edema are focal.

Question 14

dispermic fertilization

Answer 14

2 sets of paternal chromosomes

Question 15

what do hydatidiform trophoblastic cells secrete? why?

Answer 15

hCG to maintain pregnancy giving an abnormally high hCG - a partial basis for diagnosis particularly for complete hydatidiform moles.

Question 16

what happens to moles usually?

Answer 16

they are usually spontaneously aborted in the second trimester. however, remnants of trophoblastic cells may form tumors resulting in persistent trophoblastic disease.

Question 17

trophoblastic diseiase

Answer 17

tumors are usually benign, but sometimes become malignant choriodcarcinomas characterized by extensive vascularization and uterine bleeding. All GTTs are characterized by high hCG levels.