RT Journal Article SR Electronic A1 Sobek, Ales A1 Prochazka, Martin A1 Klaskova, Eva A1 Lubusky, Marek A1 Pilka, Radovan T1 High incidence of monozygotic twinning in infertility treatment JF Biomedical papers YR 2016 VO 160 IS 3 SP 358 OP 362 DO 10.5507/bp.2016.016 UL https://biomed.papers.upol.cz/artkey/bio-201603-0004.php AB Background: Monozygotic twinning is associated with increased perinatal morbidity and mortality. There is evidence that the number of monozygotic twins increases after assisted reproductive techniques. Methods: We searched PUBMED, MEDLINE, and Scopus from 1987 to 2015 for studies analyzing the incidence and possible etiology of monozygotic twinning in infertility patients and critically reviewed the current state of knowledge. Results and Conclusions: Monozygotic twinning is a rare in natural conception but occurs around twice the normal rate after assisted reproduction. Factors associated with this phenomenon remain speculative, though there is some evidence that micromanipulation techniques, prolonged culture, and genetics are involved. In view of the possible complications, adequate pre-conception counselling is advocated.