172 Obstetrics and Gynecology Board Review •••
❍ How does the fetal heart rate change in the first trimester?
It increases from 100 to 115 beats per minute (bpm) before 6 weeks to 145 to 160 bpm at 8 weeks’ gestation after
which it plateaus at 135 to 145 bpm. The variability also increases during this time.
❍ The term-missed abortion has been replaced by what term(s)?
Embryonic or fetal demise.
❍ What is the percentage chance for miscarriage after cardiac activity seen in an 8 weeks’ gestation?
2% to 3%.
❍ What are some common synonyms for an intrauterine blood collection in the first trimester?
Subchorionic hemorrhage or hematoma, implantation hemorrhage, and perigestational hemorrhage.
❍ In the presence of an intrauterine hematoma, the risk of a spontaneous abortion is associated with?
(1) Increasing size of the hematoma
(2) Advanced maternal age
(3) Earlier gestational age
(4) Structural uterine anomalies
(5) History of miscarriage
❍ True/False: An abnormal appearing yolk sac is associated with early pregnancy failure?
True.
❍ Recurrent miscarriage is defined as?
Three or more consecutive first trimester spontaneous losses.
❍ What is the arrow in this first trimester ultrasound pointing to?
Physiologic herniation of the midgut.