NURS 306 Quiz 6 OB 2026 [Latest Update] |
WCU | 100% Verified Questions & Answers |
Grade A
Question 1: Which maternal serum marker is most predictive of neural-tube defects when
elevated?
A) hCG
B) AFP
C) Inhibin-A
D) PAPP-A
Correct Answer: B) AFP
Explanation: Elevated maternal serum alpha-fetoprotein (>2.5 MoM) between 15–20 weeks
suggests open NTDs because AFP leaks into amniotic fluid through uncovered fetal vessels.
Question 2: The normal range for amniotic fluid index (AFI) in the third trimester is
A) 2–5 cm
B) 5–8 cm
C) 8–18 cm
D) 20–25 cm
,Correct Answer: C) 8–18 cm
Explanation: AFI 8–18 cm is considered normal; <5 cm indicates oligohydramnios and >24 cm
polyhydramnios, both associated with increased perinatal morbidity.
Question 3: Which uterine change is most responsible for Braxton-Hicks contractions?
A) Estrogen-induced sensitization of myometrial cells
B) Progesterone withdrawal
C) Oxytocin surge
D) Prostaglandin F2α release
Correct Answer: A) Estrogen-induced sensitization of myometrial cells
Explanation: Rising estrogen levels increase gap-junction formation and calcium-channel
expression, making the myometrium more irritable and producing painless "practice" contractions.
Question 4: A G2P1 woman at 28 weeks reports painless vaginal bleeding. Ultrasound shows
placenta covering the internal os. The most likely diagnosis is
A) Placental abruption
B) Placenta previa
C) Vasa previa
D) Cervical polyp
Correct Answer: B) Placenta previa
,Explanation: Painless bleeding in the third trimester with placenta overlying the cervix is
pathognomonic for placenta previa; digital exams are contraindicated.
Question 5: Which hormone maintains corpus luteal progesterone production until the
luteal-placental shift?
A) hCG
B) LH
C) FSH
D) Prolactin
Correct Answer: A) hCG
Explanation: hCG from the trophoblast binds LH receptors on the corpus luteum, sustaining
progesterone synthesis until the placenta takes over at ~10 weeks.
Question 6: The most accurate gestational-age dating parameter in the first trimester is
A) Last menstrual period
B) Crown-rump length on transvaginal ultrasound
C) Fundal height
D) Quickening
Correct Answer: B) Crown-rump length on transvaginal ultrasound
Explanation: CRL measures ±5 days accuracy between 7–13 weeks, outperforming menstrual
history, which can be affected by irregular cycles.
, Question 7: Which finding defines oligohydramnios?
A) AFI <5 cm or single deepest pocket <2 cm
B) AFI 8–18 cm
C) AFI >24 cm
D) MVP >8 cm
Correct Answer: A) AFI <5 cm or single deepest pocket <2 cm
Explanation: These thresholds identify decreased fluid associated with growth restriction, renal
anomalies, or ruptured membranes.
Question 8: Which antibody titer is most concerning for hemolytic disease of the fetus/newborn?
A) Anti-D >1:4
B) Anti-Kell >1:8
C) Anti-Lewis >1:16
D) Anti-M >1:32
Correct Answer: B) Anti-Kell >1:8
Explanation: Kell antibodies cause fetal anemia by suppressing erythroid precursors; titers ≥1:8 or
any rise warrant MCA-PSV surveillance.
Question 9: Which medication is contraindicated in pregnancy for hypertension?
A) Labetalol
WCU | 100% Verified Questions & Answers |
Grade A
Question 1: Which maternal serum marker is most predictive of neural-tube defects when
elevated?
A) hCG
B) AFP
C) Inhibin-A
D) PAPP-A
Correct Answer: B) AFP
Explanation: Elevated maternal serum alpha-fetoprotein (>2.5 MoM) between 15–20 weeks
suggests open NTDs because AFP leaks into amniotic fluid through uncovered fetal vessels.
Question 2: The normal range for amniotic fluid index (AFI) in the third trimester is
A) 2–5 cm
B) 5–8 cm
C) 8–18 cm
D) 20–25 cm
,Correct Answer: C) 8–18 cm
Explanation: AFI 8–18 cm is considered normal; <5 cm indicates oligohydramnios and >24 cm
polyhydramnios, both associated with increased perinatal morbidity.
Question 3: Which uterine change is most responsible for Braxton-Hicks contractions?
A) Estrogen-induced sensitization of myometrial cells
B) Progesterone withdrawal
C) Oxytocin surge
D) Prostaglandin F2α release
Correct Answer: A) Estrogen-induced sensitization of myometrial cells
Explanation: Rising estrogen levels increase gap-junction formation and calcium-channel
expression, making the myometrium more irritable and producing painless "practice" contractions.
Question 4: A G2P1 woman at 28 weeks reports painless vaginal bleeding. Ultrasound shows
placenta covering the internal os. The most likely diagnosis is
A) Placental abruption
B) Placenta previa
C) Vasa previa
D) Cervical polyp
Correct Answer: B) Placenta previa
,Explanation: Painless bleeding in the third trimester with placenta overlying the cervix is
pathognomonic for placenta previa; digital exams are contraindicated.
Question 5: Which hormone maintains corpus luteal progesterone production until the
luteal-placental shift?
A) hCG
B) LH
C) FSH
D) Prolactin
Correct Answer: A) hCG
Explanation: hCG from the trophoblast binds LH receptors on the corpus luteum, sustaining
progesterone synthesis until the placenta takes over at ~10 weeks.
Question 6: The most accurate gestational-age dating parameter in the first trimester is
A) Last menstrual period
B) Crown-rump length on transvaginal ultrasound
C) Fundal height
D) Quickening
Correct Answer: B) Crown-rump length on transvaginal ultrasound
Explanation: CRL measures ±5 days accuracy between 7–13 weeks, outperforming menstrual
history, which can be affected by irregular cycles.
, Question 7: Which finding defines oligohydramnios?
A) AFI <5 cm or single deepest pocket <2 cm
B) AFI 8–18 cm
C) AFI >24 cm
D) MVP >8 cm
Correct Answer: A) AFI <5 cm or single deepest pocket <2 cm
Explanation: These thresholds identify decreased fluid associated with growth restriction, renal
anomalies, or ruptured membranes.
Question 8: Which antibody titer is most concerning for hemolytic disease of the fetus/newborn?
A) Anti-D >1:4
B) Anti-Kell >1:8
C) Anti-Lewis >1:16
D) Anti-M >1:32
Correct Answer: B) Anti-Kell >1:8
Explanation: Kell antibodies cause fetal anemia by suppressing erythroid precursors; titers ≥1:8 or
any rise warrant MCA-PSV surveillance.
Question 9: Which medication is contraindicated in pregnancy for hypertension?
A) Labetalol
