A patient tells you that her mother was a twin, two of her sisters have twins, and several cousins either are twins or gave birth to twins. The patient, too, is expecting twins. Because there is a genetic predisposition to twins in her family, there is a good chance that the patient will have:

Question

Quizplus · Accepted Answer

A genetic predisposition to twins increases the likelihood of having dizygotic or fraternal twins, where two eggs are released and fertilized separately. Monozygotic or identical twins, where one fertilized egg splits into two, occur spontaneously and are not influenced by genetics. Nonzygotic twins is not a term commonly used in describing twin births.

A Patient Tells You That Her Mother Was a Twin