Antenatal diagnosis of all of these disorders is possible except:
**Core Concept**
Antenatal diagnosis refers to the detection of fetal abnormalities or disorders during pregnancy. This can be achieved through various methods such as ultrasound, amniocentesis, and non-invasive prenatal testing (NIPT). The ability to diagnose certain disorders antenatally allows for early intervention, improved outcomes, and informed decision-making for parents.
**Why the Correct Answer is Right**
The correct answer is related to the fact that some disorders are not amenable to antenatal diagnosis due to limitations in current diagnostic techniques or the lack of a clear genetic or pathological basis. For example, some congenital infections or metabolic disorders may not be diagnosable until after birth.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because antenatal diagnosis of chromosomal abnormalities such as Down syndrome is possible through NIPT and amniocentesis.
**Option B:** This option is incorrect because antenatal diagnosis of neural tube defects such as spina bifida can be made through ultrasound and maternal serum alpha-fetoprotein (MSAFP) screening.
**Option C:** This option is incorrect because antenatal diagnosis of certain congenital infections such as cytomegalovirus (CMV) can be made through maternal serum screening and fetal ultrasound.
**Clinical Pearl / High-Yield Fact**
It is essential for obstetricians and prenatal care providers to inform pregnant women about the limitations of antenatal diagnosis and the importance of ongoing fetal monitoring and postnatal evaluation.
**Correct Answer: D.**