Prenatal diagnosis and assessment of fetal state in pregnancy

Question 1

Methods used in screening tests

Answer 1

maternal history
maternal biochemistry
maternal virology
ultrasound

Question 2

Triple test(biochemistry)

Answer 2

B-hcg
alpha - FP
estriol

Question 3

Which two conditions are hcg elevated in

Answer 3

Down’s syndrome

Trophoblastic diseases

Question 4

which two conditions are alpha - fp elevated

Answer 4

Neural tube defects

Omphalocele and gastrochisis

Question 5

which condition is alpha - fp low in

Answer 5

Down’s syndrome

other trisomies

Question 6

Time to do fetal anomaly scan

Answer 6

18-20 weeks

Question 7

when are they done

• Amniocentesis
• Chorionic villus sampling
• Cordocentesis

Answer 7

• Amniocentesis 15 weeks or before
• Chorionic villus sampling 10 weeks or after
• Cordocentesis 20 weeks or after

Question 8

Which invasive test is associated with higher rate of miscarriage, neonatal talipes and respiratory difficulties

Answer 8

Amnioncentesis

Question 9

Which invasive test is associated with cleft lip, palate and digital amputation

Answer 9

CVS

Question 10

sfh
state the correspondences in gestational age
Symphysis pubis
Umbilicus
Below xiphisternum

Answer 10

12 weeks
22 weeks
36 weeks

Question 11

Differentials for SFH higher than gestational age

Answer 11

Wrong dates
Polyhydramnios
Multiple gestations
Intrauterine mass
Bibe baby due to maternal diabetes or constitutionally big baby
Wrong technique

Question 12

Differentials for SFH lower than gestational age

Answer 12

Wrong dates
Oligohydramnios
INtrauterine growth restriction
IUD
Constitutionally small baby
Abnormal lie
Wrong technique

Question 13

Which fetal biometry is a better measurement of gestational age before 12 weeks

Answer 13

CRL

Question 14

Which fetal biometry is a better measurement of gestational age from 12 - 20 weeks

Answer 14

BPD
HC
FL

Question 15

For maximum vertical pool, which suggests oligohydramnios and polyhydramnios

Answer 15

Oligo - <2cm

Poly - >7cm

Question 16

For AFI
oligo
poly

Answer 16

oligo - <5cm

poly - >25cm

Question 17

Define baseline fetal heart rate and normal value

Answer 17

This is the average fetal heart rate in between accelerations and decelerations; it is best
determined over 5-10mins.

normal value - 110 - 160 bpm

Question 18

Define baseline variability

Answer 18

This is the variation in the baseline rate over one minute excluding accelerations and decelerations.

Normal value is 10-25bpm

Question 19

What is baseline variability is a reflection of

Answer 19

Normal baseline variability reflects a normal autonomic nervous system and cardiac conducting system

Question 20

Define fetal heart rate accelerations

What defines a reactive trace

Answer 20

These are increases in the baseline fetal heart rate of at least 15bpm, lasting for at least 15secs.

The presence of 2 or more accelerations in 20-30-min CTG defines a reactive trace.

Question 21

Define a normal antepartum fetal CTG

Answer 21

is defined as a baseline of 120-150bpm, with
baseline variability exceeding 10bpm, and with 2 or more accelerations seen in a 20- 30-min tracing, with no decelerations.

Question 22

What is a reactive non-stress test

Answer 22

It is one with fetal heart rate acceleration of at least 2 in 20-30 minutes associated with fetal movement

Question 23

What is a positive stress test

Answer 23

Dilute oxytocin infusion or repetitive nipple stimulation is done to induce uterine contractions
A positive test is fetal cardiac decelerations in response to uterine contractions, and
this is interpreted as abnormal

It has the highest specificity for detecting the compromised
fetus

Question 24

5 components of BPP

Answer 24

amniotic fluid index
fetal tone
fetal activity (gross body movement)
fetal breathing movements

Question 25

normal BPP results

Answer 25

8-10

Question 26

Modified BPP

Answer 26

NST

AFI

Question 27

Normal fetal kick count

Answer 27

A healthy fetus usually moves or kicks about 10 times within 2
hours