Objective: To report a possible association between intracytoplasmic sperm injection (ICSI)-preimplantation genetic diagnosis (PGD) and monozygotic multiple gestation.
Design: Small case series.
Setting: In vitro fertilization unit in an academic medical center.
Patient(s): Three patients were treated with ICSI-PGD for sexing as well as selection against a known translocation.
Intervention(s): Transfer of day 4 embryos to the uterus.
Main outcome measure(s): Clinical pregnancy.
Result(s): Two pairs of monozygotic twins and a triplet pregnancy.
Conclusion(s): Repeated manipulation of the zona pellucida as well as extended embryo culture during ICSI-PGD treatments may result in monozygotic twin and triplet pregnancies.