Background: Paternal dispermy can be the pathogenesis of complete molar pregnancy.
Case: A 23-year-old, white woman, gravida 4, para 1, was pregnant with a twin gestation by ovulation induction with metrodin. Ultrasound evaluation confirmed an intrauterine pregnancy in conjunction with what appeared to be a hydatidiform mole. The karyotype in the molar pregnancy, obtained from chorionic villus sampling, showed a pair of paternally derived inverted chromosomes 9, confirming the diagnosis of a complete mole. Uncontrollable hemorrhage with a rapid rise in the beta-human chorionic gonadotropin titer necessitated evacuation of the uterus. The patient was followed with beta-human chorionic gonadotropin titers for a year, with no evidence of recurrence.
Conclusion: This case illustrates paternal disomy in a complete molar pregnancy documented by a paternal chromosome 9 inversion.