Question

Husband asks for paternal testing of his twins. One twin is found to be his son & other is not. Diagnosis?

• A. Superfecundation
• B. Superfoetation
• C. Posthumous child
• D. None of the above

Hint:

Consider which condition allows twins in the same pregnancy to have different biological fathers.

Answer 1

The Correct Option is A

Step 1: Understand the clinical scenario.
A husband undergoes paternity testing of his twins and discovers that one twin is biologically his son while the other is not. This means the two twins have different biological fathers.

Step 2: Define the relevant terms.
Superfecundation is the fertilization of two or more ova released during the same menstrual cycle by spermatozoa from separate acts of sexual intercourse, potentially from different males. This results in twins with different biological fathers (heteropaternal superfecundation). Superfoetation refers to fertilization of a second ovum during an already established pregnancy -- an extremely rare event producing fetuses of different gestational ages. Posthumous child refers to a child born after the father's death, which is unrelated to this scenario.

Step 3: Apply to the scenario.
Since paternity testing reveals twins from the same pregnancy with different biological fathers, this is the hallmark of heteropaternal superfecundation. Two ova were released in the same menstrual cycle and each was fertilized by spermatozoa from a different man.

Conclusion: The correct answer is Superfecundation.