Monozygotic triplet pregnancies are very rare, even after in vitro fertilization (IVF). We present a case of a live birth of triplets from a monochorionic triamniotic pregnancy after blastocyst transfer. A 29-year-old woman underwent intracytoplasmic sperm injection (IVF-ICSI). Her medical history included a 4-year infertility treatment with ovarian stimulation, three cycles of intrauterine insemination, hysteroscopy and an unsuccessful attempt at IVF. During the second IVF attempt, the patient underwent ovulation simulation according to the long GnRH agonist protocol. Eleven metaphase II (MII) oocytes were injected with spermatozoa, resulting in four expanded blastocysts. In the end, two blastocysts (4AA) were transferred into the uterine cavity. Ultrasound examination performed at 7 weeks of gestation showed an ongoing triamniotic triplet pregnancy. Regular uterine contractions began at 33 weeks of gestation and a cesarean section was performed, resulting in a birth of three healthy girls, weighing 2060g (Apgar 7), 1860g (Apgar 6), 2000g (Apgar 6). After 13 days of hospitalization the infants and the mother were discharged home.
Conclusion: The causes of monozygotic multiple gestations in spontaneous and ART pregnancies are poorly understood. They seem to occur more often after IVF. Any definitive relationship between particular stages of the IVF procedure and monozygotic multiple pregnancies remains controversial.