ABSTRACT
OBJECTIVE: Monochorionic-triamniotic (MCTA) triplet pregnancies following artificial reproductive technologies are uncommon. We report a case in which one of two transferred embryos differentiated into an MCTA triplet. This study aimed to investigate the potential factors contributing to MCTA triplet pregnancy. CASE REPORT: A 39-year-old woman underwent her second frozen embryo transfer with hatching blastocysts, which resulted in the detection of an MCTA triplet on ultrasonography. She delivered by cesarean section at 32 weeks of gestation, resulting in the birth of three live male infants. Her medical history and in vitro fertilization treatment were reviewed to identify potential causes. CONCLUSION: The etiology of MCTA triplet pregnancy remains multifactorial. In the presented case, prolonged in vitro culture to the blastocyst stage and inner cell mass splitting were potential contributing factors. Further research is needed to fully understand the complexity of MCTA triplet pregnancy.