Are Monochorionic Twins More Likely Subsequent to Blastocyst Transfer? A Case Report and Experience With the “German Middle Way”

Since the introduction of assisted reproductive techniques the amounts of monozygotic twins (MZTs) have been rising. Several studies have suggested that blastocyst culture and the associated prolonged in vitro cultivation time might play a role in the manifestation of monochorionic twins. Due to the recent changes in the interpretation of the German Embryo Protection Act, it became accepted for patients and doctors in some regions of Germany to select for the most suitable embryo prior to implantation, referred to as the “German middle way”. We report a rare case of two sets of monochorionic and diamniotic twins subsequent to blastocyst transfer. A missed abortion of one of the twin sets occurred at the eighth week of gestation. The ongoing pregnancy showed no further signs of pathology and two healthy twins were delivered per cesarean section at 38 weeks. This case demonstrates that patients should be well informed concerning the risk for monochorionic twins subsequent to blastocyst transfer. In our experience, however, blastocyst transfer on day 5 does not seem to increase the risk for monochorionic twins compared to in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) with transfer on day 2. J Clin Gynecol Obstet. 2014;3(3):114-116 doi: http://dx.doi.org/10.14740/jcgo274w