Which of the following is true regarding chorionicity in multifetal pregnancy
**Core Concept**
Chorionicity in multifetal pregnancy refers to the number of separate placentas or the presence of a single placenta (monochorionic) shared by multiple fetuses. This concept is crucial in prenatal diagnosis and management of twin-to-twin transfusion syndrome, discordant growth, and other complications.
**Why the Correct Answer is Right**
In multifetal pregnancies, chorionicity is determined by whether the fetuses share a single placenta (monochorionic-diamniotic, monochorionic-monoamniotic) or have separate placentas (dichorionic-diamniotic). Monochorionic placentas are formed when a single fertilized egg splits in two (monozygotic twins), while dichorionic placentas are formed when two separate eggs are fertilized (dizygotic twins). The correct answer depends on the specific scenario of the multifetal pregnancy.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the chorionicity of the multifetal pregnancy, making it impossible to determine the correct answer.
**Option B:** This option is incorrect because it is too vague and does not provide any information about the chorionicity of the multifetal pregnancy.
**Option C:** This option is incorrect because it is a distractor and does not accurately describe the chorionicity of multifetal pregnancies.
**Clinical Pearl / High-Yield Fact**
Monochorionic placentas are associated with an increased risk of twin-to-twin transfusion syndrome, a condition where one twin receives more blood than the other, leading to growth restriction and potentially life-threatening complications.
**Correct Answer: C.**