ARDMS OB/GYN Sonography Certification Exam 2026:
Comprehensive Board Practice Test — Obstetric Ultrasound, Fetal
Anatomy, Gynaecologic Pathology, Reproductive Health, Maternal
Complications & Clinical Interpretation — 190 Multiple-Choice
Questions with Answers & Detailed Rationales
Obstetrics & Gynecology Sonographer ARDMS Practice Examination
Section 1: First Trimester Obstetrics (Questions 1–25)
Question 1
A 28-year-old G2P1 patient presents for a dating ultrasound at 7 weeks gestation by LMP.
The sonographer identifies a gestational sac within the endometrial cavity. Which
sonographic finding is most consistent with a normal intrauterine pregnancy at this
gestational age?
A. Gestational sac with a double decidual sign and yolk sac present
B. Gestational sac with an echogenic ring and no visible contents
C. Gestational sac with a fetal pole measuring 10 mm and no cardiac activity
D. Gestational sac with a pseudogestational sign and free fluid in the cul-de-sac
Correct Answer: A
Explanation:
The double decidual sign and yolk sac presence confirm normal intrauterine pregnancy at 7
weeks. The yolk sac should be visible when the gestational sac exceeds 8 mm.
Question 2
,A 32-year-old female with a history of ectopic pregnancy presents with pelvic pain and a
positive beta-hCG. Transvaginal ultrasound reveals an empty uterus, a complex adnexal mass
separate from the ovary, and free fluid in the pouch of Douglas. What is the most likely
diagnosis?
A. Corpus luteum cyst
B. Ruptured ectopic pregnancy
C. Ovarian torsion
D. Early intrauterine pregnancy
Correct Answer: B
Explanation:
An adnexal mass separate from the ovary with free pelvic fluid in a patient with positive hCG
strongly suggests ruptured ectopic pregnancy requiring immediate intervention.
Question 3
At what gestational age does the fetal heart normally begin to be visualized on transvaginal
ultrasound?
A. 4 weeks
B. 5 weeks
C. 6 weeks
D. 8 weeks
Correct Answer: C
Explanation:
,Cardiac activity is typically visualized transvaginally at 6 weeks gestation when the fetal pole
measures approximately 5 mm or greater.
Question 4
A sonographer is performing a first-trimester scan and identifies a cystic structure within the
fetal head at 12 weeks. Which structure is this most likely to represent?
A. Choroid plexus cyst
B. Cystic hygroma
C. Physiologic rhombencephalon
D. Dandy-Walker malformation
Correct Answer: C
Explanation:
The rhombencephalon is a normal transient cystic structure in the first trimester that
typically resolves by 14 weeks gestation. It should not be mistaken for pathology.
Question 5
Which sonographic parameter is most accurate for establishing gestational age in the first
trimester?
A. Gestational sac diameter
B. Crown-rump length
C. Yolk sac diameter
D. Beta-hCG levels
, Correct Answer: B
Explanation:
Crown-rump length between 7-13 weeks is the most accurate biometric parameter for
pregnancy dating with a margin of error of ±5 days.
Question 6
A 35-year-old G3P2 patient at 11 weeks gestation undergoes nuchal translucency screening.
The NT measurement is 3.5 mm. What does this finding most likely indicate?
A. Normal variant requiring no further evaluation
B. Increased risk for chromosomal abnormalities
C. Confirmatory diagnosis of Down syndrome
D. Technical error requiring repeat measurement
Correct Answer: B
Explanation:
NT greater than 3.0 mm is considered increased and warrants further genetic counseling and
testing, though it is not diagnostic of any specific condition.
Question 7
Which of the following best describes the sonographic appearance of a subchorionic
hematoma?
A. Anechoic collection between the chorion and myometrium
B. Echogenic mass within the amniotic cavity
Comprehensive Board Practice Test — Obstetric Ultrasound, Fetal
Anatomy, Gynaecologic Pathology, Reproductive Health, Maternal
Complications & Clinical Interpretation — 190 Multiple-Choice
Questions with Answers & Detailed Rationales
Obstetrics & Gynecology Sonographer ARDMS Practice Examination
Section 1: First Trimester Obstetrics (Questions 1–25)
Question 1
A 28-year-old G2P1 patient presents for a dating ultrasound at 7 weeks gestation by LMP.
The sonographer identifies a gestational sac within the endometrial cavity. Which
sonographic finding is most consistent with a normal intrauterine pregnancy at this
gestational age?
A. Gestational sac with a double decidual sign and yolk sac present
B. Gestational sac with an echogenic ring and no visible contents
C. Gestational sac with a fetal pole measuring 10 mm and no cardiac activity
D. Gestational sac with a pseudogestational sign and free fluid in the cul-de-sac
Correct Answer: A
Explanation:
The double decidual sign and yolk sac presence confirm normal intrauterine pregnancy at 7
weeks. The yolk sac should be visible when the gestational sac exceeds 8 mm.
Question 2
,A 32-year-old female with a history of ectopic pregnancy presents with pelvic pain and a
positive beta-hCG. Transvaginal ultrasound reveals an empty uterus, a complex adnexal mass
separate from the ovary, and free fluid in the pouch of Douglas. What is the most likely
diagnosis?
A. Corpus luteum cyst
B. Ruptured ectopic pregnancy
C. Ovarian torsion
D. Early intrauterine pregnancy
Correct Answer: B
Explanation:
An adnexal mass separate from the ovary with free pelvic fluid in a patient with positive hCG
strongly suggests ruptured ectopic pregnancy requiring immediate intervention.
Question 3
At what gestational age does the fetal heart normally begin to be visualized on transvaginal
ultrasound?
A. 4 weeks
B. 5 weeks
C. 6 weeks
D. 8 weeks
Correct Answer: C
Explanation:
,Cardiac activity is typically visualized transvaginally at 6 weeks gestation when the fetal pole
measures approximately 5 mm or greater.
Question 4
A sonographer is performing a first-trimester scan and identifies a cystic structure within the
fetal head at 12 weeks. Which structure is this most likely to represent?
A. Choroid plexus cyst
B. Cystic hygroma
C. Physiologic rhombencephalon
D. Dandy-Walker malformation
Correct Answer: C
Explanation:
The rhombencephalon is a normal transient cystic structure in the first trimester that
typically resolves by 14 weeks gestation. It should not be mistaken for pathology.
Question 5
Which sonographic parameter is most accurate for establishing gestational age in the first
trimester?
A. Gestational sac diameter
B. Crown-rump length
C. Yolk sac diameter
D. Beta-hCG levels
, Correct Answer: B
Explanation:
Crown-rump length between 7-13 weeks is the most accurate biometric parameter for
pregnancy dating with a margin of error of ±5 days.
Question 6
A 35-year-old G3P2 patient at 11 weeks gestation undergoes nuchal translucency screening.
The NT measurement is 3.5 mm. What does this finding most likely indicate?
A. Normal variant requiring no further evaluation
B. Increased risk for chromosomal abnormalities
C. Confirmatory diagnosis of Down syndrome
D. Technical error requiring repeat measurement
Correct Answer: B
Explanation:
NT greater than 3.0 mm is considered increased and warrants further genetic counseling and
testing, though it is not diagnostic of any specific condition.
Question 7
Which of the following best describes the sonographic appearance of a subchorionic
hematoma?
A. Anechoic collection between the chorion and myometrium
B. Echogenic mass within the amniotic cavity
