UW+Mehlm AFP levels 02-14 (1)

Question 1

UW. table. Decr. AFP? 1

Answer 1

Aneuploidies, eg 18 or 21

Question 2

UW. table. Incr. AFP? 3

Answer 2

Open neural tube defects (eg anencephaly, open spina bifida)

Ventral wall defects (eg omphalocele, gastrochisis)

Multiple gestations

Question 3

UW. what produces AFP?

Answer 3

protein produced by the fetal liver and gastrointestinal tract

Question 4

UW. where is present AFP?

Answer 4

present in fetal serum and amniotic fluid.
It is absorbed into the maternal circulation.

Question 5

UW. quad screening for what?

Answer 5

screening test for fetal aneuploidy and congenital defects

Question 6

UW. AFP incr in multiple gestations why?

Answer 6

due to greater fetal tissue volume capable of producing AFP

Question 7

UW. AFP incr. in inaccurate pregnancy dating (because AFP fluctuates with gestational age).

Answer 7

.

Question 8

UW. AFP incr. in inaccurate pregnancy dating. Pagal kad tipo ziurim kad butu accurate?

Answer 8

eg last menstrual period is consistent with fundal height

Question 9

UW. Case - one baby + accurate pregnancy datings. Elevated AFP. Cause?

Answer 9

elevated AFP level suggests a congenital defect

Question 10

UW. abdominal and neuro tube defects allow for greater leakage of AFP into the amniotic fluid, which elevates AFP levels.

Answer 10

.

Question 11

UW. further evaluation post quad test?

Answer 11

Further evaluation is with an ultrasound to evaluate fetal anatomy and confirm pregnancy dating.

Question 12

UW. In what other cases in adult can be incr. AFP?

Answer 12

liver disease (eg, HCC, viral hepatitis) and ovarian germ cell tumors (eg, endodermal sinus tumors, embryonal carcinoma).
This patient (in case) has no symptoms of liver disease (eg, ascites, jaundice) or of an ovarian germ cell tumor (eg, abdominal distension and pain), making a fetal etiology more likely.

Question 13

Mehl. Most common cause of abnormal AFP measurement is ???

Answer 13

“dating error.”

Question 14

Mehl. The USMLE Q will tell you that a pregnant woman has AFP measured 2.6 times the upper limit of normal for her gestational age; next best step =??

Answer 14

“ultrasound”!!!!!!!!!!! [to confirm pregnancy dating]

wrong - “re-measure AFP”

Question 15

Mehl. “re-measure AFP” is wrong because - AFP value measured by the lab isn’t wrong; it’s merely that the estimated gestational age of the pregnancy is wrong. An ultrasound will allow for a re-measuring of the crown-rump length (CRL), which is a typical method for ascertaining approximate gestational age.

Answer 15

.

Question 16

Mehl. apart from dating error also can be increased. Classic cause?

Answer 16

Apart from dating error, classic cause is neural tube defects (i.e., spina bifida).

Question 17

Mehl. Other causes of ­ incr. AFP for usmle are…?3

Answer 17

anencephaly, multiple gestation pregnancies, and omphalocele / gastroschisis.

Question 18

Mehl. too low AFP. Case?

Answer 18

As discussed before, AFP is “down in Down syndrome.”
It’s also low in Edward and Patau but USMLE doesn’t care.

Question 19

UW. 29y.o + 16 weeks. uterus 20 weeks gest. ALP - 3,8 multiples normal. Best next step?

Answer 19

FETAL ULTRASOUND

Question 20

UW. neural tube defects. Risk factors? 4

Answer 20

low folic acid;
methotrexate, entiepilectis
DM
prior pregnancy with neural tube defects

Question 21

UW. neural tube defects. prenatal screening. 2

Answer 21

AFP
2nd trimester UG

Question 22

UW. neural tube defects. prevention in average risk?

Answer 22

0,4 mg folic acid daily

Question 23

UW. neural tube defects. prevention in high risk?

Answer 23

4 mg folic acid daily

Question 24

UW. neural tube defects. when is performed screening for these pathologies?

Answer 24

2nd trimester, 15-20 weeks

Question 25

UW. MCC of high AFP?

Answer 25

incorrect gestational age dating

Question 26

UW. abnormal MSAFP level requires ….??? best next step

Answer 26

requires fetal ultrasound, which can detect multiple gestations, determine an accurate gestational age, and visualize fetal CNS structures.

Question 27

UW. neural tube defects.
A repeat AFP level, even if normal, cannot exclude an NTD due to a tendency for values to regress to the mean, leading to a falsely reassuring result.

Answer 27

.

Question 28

UW. neural tube defects.
A quantitative β-hCG level can be measured in the first trimester to evaluate for suspected abnormal pregnancies (eg, ectopic, hydatidiform mole).

Second-trimester levels, which cannot assess fetal status, do not affect obstetric management.

Answer 28

.

Question 29

(Choice A) AFP and CA-125 are ovarian tumor markers, but both are commonly elevated in pregnancy. CA-125 levels are not measured in young patients (ie, those at low cancer risk) unless they have undergone surgery for ovarian cancer and require levels to follow disease progression.

Answer 29

.